Bio


Professor Chang's primary research interest is in the areas of multi-functional materials and intelligent structures with particular emphases on structural health monitoring, intelligent self-sensing diagnostics, and multifunctional energy storage composites for transportation vehicles as well as safety-critical assets and medical devices. His specialties include embedded sensors and stretchable sensor networks with built-in self-diagnostics, integrated diagnostics and prognostics, damage tolerance and failure analysis for composite materials, and advanced multi-physics computational methods for multi-functional structures. Most of his work involves system integration and multi-disciplinary engineering in structural mechanics, electrical engineering, signal processing, and multi-scale fabrication of materials. His recent research topics include: Multifunctional energy storage composites, Integrated health management for aircraft structures, bio-inspired intelligent sensory materials for fly-by-feel autonomous vehicles, active sensing diagnostics for composite structures, self-diagnostics for high-temperature materials, etc.

Academic Appointments


Honors & Awards


  • Life-Time Achievement Award, Society of Prognostic Health Management (2018)
  • Life-Time Achievement Award, SPIE NDE/SHM (2010)
  • Structural Health Monitoring (SHM) Lifetime Achievement Award, International Workshop on Structural Health Monitoring (2004)
  • Fellow, American Institute of Aeronautics and Astronautics (AIAA) (2001)
  • Fellow, American Society of Mechanical Engineers (ASME) (1998)
  • Presidential Young Investigator Award, National Science Foundation (1988)

Boards, Advisory Committees, Professional Organizations


  • Co-founder and chair, Aerospace Industry Steering Committee on Structural Health Monitoring (AISC-SHM) (2006 - 2008)
  • member, US Army Research Laboratories Advisory Board (2014 - 2017)
  • Chair and organizer, International Workshop on Structural Health Monitoring (1997 - Present)
  • Editor-in-Chief, Int. J. of Structural Health Monitoring (2012 - Present)
  • Associate Editor, AIAA Journal (2024 - Present)

Professional Education


  • PhD, Michigan (1983)

2024-25 Courses


Stanford Advisees


  • Postdoctoral Faculty Sponsor
    Tanay Topac
  • Master's Program Advisor
    Adam Ctverak, Jason Gunn, Bryan Tiang, Martin Zhou
  • Doctoral (Program)
    Gabriela Gonzalez Ayala

All Publications


  • Thermo-mechanical properties of shape-recoverable structural composites via vacuum-assisted resin transfer molding process and in-situ polymerization of poly (tert-butyl acrylate-co-acrylic acid) copolymer COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING Jeon, J., So, B., Choi, Y., Han, Y., Kim, T., Shin, G., Lee, J., Kim, H., Kim, J., Farhangdoust, S., Chang, F., Kim, M., Lee, M., Yun, S., Kang, T. 2024; 185
  • Design and Manufacture of Multifunctional 3-D Smart Skins with Embedded Sensor Networks for Robotic Applications. Sensors (Basel, Switzerland) Ransom, E., Chen, X., Mangram, W., Nasrollahi, A., Topac, T., Chang, F. K. 2024; 24 (11)

    Abstract

    An investigation was performed to develop a process to design and manufacture a 3-D smart skin with an embedded network of distributed sensors for non-developable (or doubly curved) surfaces. A smart skin is the sensing component of a smart structure, allowing such structures to gather data from their surrounding environments to make control and maintenance decisions. Such smart skins are desired across a wide variety of domains, particularly for those devices where their surfaces require high sensitivity to external loads or environmental changes such as human-assisting robots, medical devices, wearable health components, etc. However, the fabrication and deployment of a network of distributed sensors on non-developable surfaces faces steep challenges. These challenges include the conformal coverage of a target object without causing prohibitive stresses in the sensor interconnects and ensuring positional accuracy in the skin sensor deployment positions, as well as packaging challenges resulting from the thin, flexible form factor of the skin. In this study, novel and streamlined processes for making such 3-D smart skins were developed from the initial sensor network design to the final integrated skin assembly. Specifically, the process involved the design of the network itself (for which a physical simulation-based optimization was developed), the deployment of the network to a targeted 3D surface (for which a specialized tool was designed and implemented), and the assembly of the final skin (for which a novel process based on dip coating was developed and implemented.).

    View details for DOI 10.3390/s24113441

    View details for PubMedID 38894231

    View details for PubMedCentralID PMC11175095

  • Design of Active Sensing Smart Skin for Incipient Slip Detection in Robotics Applications IEEE-ASME TRANSACTIONS ON MECHATRONICS Liu, C., Huh, T., Chen, S. X., Lu, L., Kopsaftopoulos, F., Cutkosky, M. R., Chang, F. 2022
  • Enabling self-shape estimation of composite structures using distributed microfabricated strain gauge networks JOURNAL OF COMPOSITE MATERIALS Chen, X., Nasrollahi, A., Ransom, E., Topac, T., Chang, F. 2022
  • Si-based self-programming neuromorphic integrated circuits for intelligent morphing wings JOURNAL OF COMPOSITE MATERIALS Nathan, D., Deo, A., Haughn, K., Yi, S., Lee, J., Gao, D., Shenoy, R., Xu, M., Tran, I. C., Zheng, J., Rong, Z., Wang, M., Shaffer, C. M., Wu, C., Topac, T., Chen, X., He, L., Chang, F., Williams, R., Inman, D. J., Chen, Y. 2022
  • Hybrid Models for Situational Awareness of an Aerial Vehicle from Multimodal Sensing AIAA JOURNAL Topac, O., Ha, S., Chen, X., Gamble, L., Inman, D., Chang, F. 2022

    View details for DOI 10.2514/1.J061926

    View details for Web of Science ID 000876402500001

  • Warped Gaussian processes for predicting the degradation of aerospace structures STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Pfingstl, S., Braun, C., Nasrollahi, A., Chang, F., Zimmermann, M. 2022
  • A systematic approach to resolve high impedance of multifunctional energy storage composites JOURNAL OF ENERGY STORAGE Bombik, A., Ha, S., Nasrollahi, A., Chang, F. 2022; 54
  • Design of a Robust Tool for Deploying Large-Area Stretchable Sensor Networks from Microscale to Macroscale. Sensors (Basel, Switzerland) Ransom, E., Chen, X., Chang, F. 2022; 22 (13)

    Abstract

    An investigation was conducted to develop an effective automated tool to deploy micro-fabricated stretchable networks of distributed sensors onto the surface of large structures at macroscale to create "smart" structures with embedded distributed sensor networks. Integrating a large network of distributed sensors with structures has been a major challenge in the design of so-called smart structures or devices for cyber-physical applications where a large amount of usage data from structures or devices can be generated for artificial intelligence applications. Indeed, many "island-and-serpentine"-type distributed sensor networks, while promising, remain difficult to deploy. This study aims to enable such networks to be deployed in a safe, automated, and efficient way. To this end, a scissor-hinge controlled system was proposed as the basis for a deployment mechanism for such stretchable sensor networks (SSNs). A model based on a kinematic scissor-hinge mechanism was developed to simulate and design the proposed system to automatically stretch a micro-scaled square network with uniformly distributed sensor nodes. A prototype of an automatic scissor-hinge stretchable tool was constructed during the study with an array of four scissor-hinge mechanisms, each belt-driven by a single stepper motor. Two micro-fabricated SSNs from a 100 mm wafer were fabricated at the Stanford Nanofabrication Facility for this deployment study. The networks were designed to be able to cover an area 100 times their manufacturing size (from a 100 mm diameter wafer to a 1 m2 active area) once stretched. It was demonstrated that the proposed deployment tool could place sensor nodes in prescribed locations efficiently within a drastically shorter time than in current labor-intensive manual deployment methods.

    View details for DOI 10.3390/s22134856

    View details for PubMedID 35808351

  • Numerical and experimental evaluation of mechanical performance of the multifunctional energy storage composites JOURNAL OF COMPOSITE MATERIALS Wang, Y., Chang, F. 2021
  • Kirigami auxetic structure for high efficiency power harvesting in self-powered and wireless structural health monitoring systems SMART MATERIALS AND STRUCTURES Farhangdoust, S., Georgeson, G., Ihn, J., Chang, F. 2021; 30 (1)
  • Reliability of crack quantification via acousto-ultrasound active-sensing structural health monitoring using surface-mounted PZT actuators/sensors STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Yadav, S., Mishra, S., Kopsaftopoulos, F., Chang, F. 2020
  • Design and Integration of a Wireless Stretchable Multimodal Sensor Network in a Composite Wing. Sensors (Basel, Switzerland) Chen, X., Maxwell, L., Li, F., Kumar, A., Ransom, E., Topac, T., Lee, S., Faisal Haider, M., Dardona, S., Chang, F. 2020; 20 (9)

    Abstract

    This article presents the development of a stretchable sensor network with high signal-to-noise ratio and measurement accuracy for real-time distributed sensing and remote monitoring. The described sensor network was designed as an island-and-serpentine type network comprising a grid of sensor "islands" connected by interconnecting "serpentines." A novel high-yield manufacturing process was developed to fabricate networks on recyclable 4-inch wafers at a low cost. The resulting stretched sensor network has 17 distributed and functionalized sensing nodes with low tolerance and high resolution. The sensor network includes Piezoelectric (PZT), Strain Gauge (SG), and Resistive Temperature Detector (RTD) sensors. The design and development of a flexible frame with signal conditioning, data acquisition, and wireless data transmission electronics for the stretchable sensor network are also presented. The primary purpose of the frame subsystem is to convert sensor signals into meaningful data, which are displayed in real-time for an end-user to view and analyze. The challenges and demonstrated successes in developing this new system are demonstrated, including (a) developing separate signal conditioning circuitry and components for all three sensor types (b) enabling simultaneous sampling for PZT sensors for impact detection and (c) configuration of firmware/software for correct system operation. The network was expanded with an in-house developed automated stretch machine to expand it to cover the desired area. The released and stretched network was laminated into an aerospace composite wing with edge-mount electronics for signal conditioning, processing, power, and wireless communication.

    View details for DOI 10.3390/s20092528

    View details for PubMedID 32365628

  • Static Tactile Sensing for a Robotic Electronic Skin via an Electromechanical Impedance-Based Approach. Sensors (Basel, Switzerland) Liu, C. n., Zhuang, Y. n., Nasrollahi, A. n., Lu, L. n., Haider, M. F., Chang, F. K. 2020; 20 (10)

    Abstract

    Tactile sensing is paramount for robots operating in human-centered environments to help in understanding interaction with objects. To enable robots to have sophisticated tactile sensing capability, researchers have developed different kinds of electronic skins for robotic hands and arms in order to realize the 'sense of touch'. Recently, Stanford Structures and Composites Laboratory developed a robotic electronic skin based on a network of multi-modal micro-sensors. This skin was able to identify temperature profiles and detect arm strikes through embedded sensors. However, sensing for the static pressure load is yet to be investigated. In this work, an electromechanical impedance-based method is proposed to investigate the response of piezoelectric sensors under static normal pressure loads. The smart skin sample was firstly fabricated by embedding a piezoelectric sensor into the soft silicone. Then, a series of static pressure tests to the skin were conducted. Test results showed that the first peak of the real part impedance signal was sensitive to static pressure load, and by using the proposed diagnostic method, this test setup could detect a resolution of 0.5 N force. Numerical simulation methods were then performed to validate the experimental results. The results of the numerical simulation prove the validity of the experiments, as well as the robustness of the proposed method in detecting static pressure loads using the smart skin.

    View details for DOI 10.3390/s20102830

    View details for PubMedID 32429364

  • Multifunctional energy storage composite structures with embedded lithium-ion batteries JOURNAL OF POWER SOURCES Ladpli, P., Nardari, R., Kopsaftopoulos, F., Chang, F. 2019; 414: 517–29
  • A Self-Adaptive 1D Convolutional Neural Network for Flight-State Identification. Sensors (Basel, Switzerland) Chen, X., Kopsaftopoulos, F., Wu, Q., Ren, H., Chang, F. 2019; 19 (2)

    Abstract

    The vibration of a wing structure in the air reflects coupled aerodynamic⁻mechanical responses under varying flight states that are defined by the angle of attack and airspeed. It is of great challenge to identify the flight state from the complex vibration signals. In this paper, a novel one-dimension convolutional neural network (CNN) is developed, which is able to automatically extract useful features from the structural vibration of a recently fabricated self-sensing wing through wind-tunnel experiments. The obtained signals are firstly decomposed into various subsignals with different frequency bands via dual-tree complex-wavelet packet transformation. Then, the reconstructed subsignals are selected to form the best combination for multichannel inputs of the CNN. A swarm-based evolutionary algorithm called grey-wolf optimizer is utilized to optimize a set of key parameters of the CNN, which saves considerable human efforts. Two case studies demonstrate the high identification accuracy and robustness of the proposed method over standard deep-learning methods in flight-state identification, thus providing new perspectives in self-awareness toward the next generation of intelligent air vehicles.

    View details for PubMedID 30641961

  • A Self-Adaptive 1D Convolutional Neural Network for Flight-State Identification SENSORS Chen, X., Kopsaftopoulos, F., Wu, Q., Ren, H., Chang, F. 2019; 19 (2)

    View details for DOI 10.3390/s19020275

    View details for Web of Science ID 000458569300058

  • Active Sensing for Measuring Contact of Thin Film Gecko-Inspired Adhesives IEEE ROBOTICS AND AUTOMATION LETTERS Tae Myung Huh, Liu, C., Hashizume, J., Chen, T. G., Suresh, S. A., Chang, F., Cutkosky, M. R. 2018; 3 (4): 3263–70
  • Characterization of Distributed Microfabricated Strain Gauges on Stretchable Sensor Networks for Structural Applications SENSORS Chen, X., Topac, T., Smith, W., Ladpli, P., Liu, C., Chang, F. 2018; 18 (10)

    View details for DOI 10.3390/s18103260

    View details for Web of Science ID 000448661500088

  • Characterization of Distributed Microfabricated Strain Gauges on Stretchable Sensor Networks for Structural Applications. Sensors (Basel, Switzerland) Chen, X., Topac, T., Smith, W., Ladpli, P., Liu, C., Chang, F. 2018; 18 (10)

    Abstract

    Smart structures mimic biological systems by using thousands of sensors serving as a nervous system analog. One approach to give structures this sensing ability is to develop a multifunctional sensor network. Previous work has demonstrated stretchable sensor networks consisting of temperature sensors and impact detectors for monitoring external environments and interacting with other objects. The objective of this work is to develop distributed, robust and reliable strain gauges for obtaining the strain distribution of a designated region on the target structure. Here, we report a stretchable network that has 27 rosette strain gauges, 6 resistive temperature devices and 8 piezoelectric transducers symmetrically distributed over an area of 150 * 150 mm to map and quantify multiple physical stimuli with a spatial resolution of 2.5 * 2.5 mm. We performed computational modeling of the network stretching process to improve measurement accuracy and conducted experimental characterizations of the microfabricated strain gauges to verify their gauge factor and temperature coefficient. Collectively, the results represent a robust and reliable sensing system that is able to generate a distributed strain profile of a common structure. The reported strain gauge network may find a wide range of applications in morphing wings, smart buildings, autonomous cars and intelligent robots.

    View details for PubMedID 30274158

  • Integrity monitoring of adhesively bonded joints via an electromechanical impedance-based approach STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Zhuang, Y., Kopsaftopoulos, F., Dugnani, R., Chang, F. 2018; 17 (5): 1031–45
  • Functionalization of stretchable networks with sensors and switches for composite materials STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Guo, Z., Kim, K., Salowitz, N., Lanzara, G., Wang, Y., Peumans, P., Chang, F. 2018; 17 (3): 598–623
  • Flight State Identification of a Self-Sensing Wing via an Improved Feature Selection Method and Machine Learning Approaches SENSORS Chen, X., Kopsaftopoulos, F., Wu, Q., Ren, H., Chang, F. 2018; 18 (5)

    View details for DOI 10.3390/s18051379

    View details for Web of Science ID 000435580300078

  • Estimating state of charge and health of lithium-ion batteries with guided waves using built-in piezoelectric sensors/actuators JOURNAL OF POWER SOURCES Ladpli, P., Kopsaftopoulos, F., Chang, F. 2018; 384: 342–54
  • Flight State Identification of a Self-Sensing Wing via an Improved Feature Selection Method and Machine Learning Approaches. Sensors (Basel, Switzerland) Chen, X., Kopsaftopoulos, F., Wu, Q., Ren, H., Chang, F. 2018; 18 (5)

    Abstract

    In this work, a data-driven approach for identifying the flight state of a self-sensing wing structure with an embedded multi-functional sensing network is proposed. The flight state is characterized by the structural vibration signals recorded from a series of wind tunnel experiments under varying angles of attack and airspeeds. A large feature pool is created by extracting potential features from the signals covering the time domain, the frequency domain as well as the information domain. Special emphasis is given to feature selection in which a novel filter method is developed based on the combination of a modified distance evaluation algorithm and a variance inflation factor. Machine learning algorithms are then employed to establish the mapping relationship from the feature space to the practical state space. Results from two case studies demonstrate the high identification accuracy and the effectiveness of the model complexity reduction via the proposed method, thus providing new perspectives of self-awareness towards the next generation of intelligent air vehicles.

    View details for PubMedID 29710832

  • A stochastic global identification framework for aerospace structures operating under varying flight states MECHANICAL SYSTEMS AND SIGNAL PROCESSING Kopsaftopoulos, F., Nardari, R., Li, Y., Chang, F. 2018; 98: 425-447
  • Design and analysis of radially polarized screen-printed piezoelectric transducers JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Salowitz, N. P., Kim, S., Kopsaftopoulos, F., Li, Y., Chang, F. 2017; 28 (7): 934-946
  • Stand-Alone Stretchable Absolute Pressure Sensing System for Industrial Applications IEEE Transactions on Industrial Electronics Guo, Y., Schütz, S., Vaghi, A., Li, Y., Guo, Z., Chang, F., Barrettino, D., Wang, S. X. 2017; 64 (11): 8739-8746

    View details for DOI 10.1109/TIE.2017.2701763

  • Analytical model of lap-joint adhesive with embedded piezoelectric transducer for weak bond detection JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Dugnani, R., Chang, F. 2017; 28 (1): 124-140
  • Adhesive bond-line degradation detection via a cross-correlation electromechanical impedance-based approach STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Dugnani, R., Zhuang, Y., Kopsaftopoulos, F., Chang, F. 2016; 15 (6): 650-667
  • A Super Stretchable Organic Thin-Film Diodes Network That Can Be Embedded Into Carbon Fiber Composite Materials for Sensor Network Applications JOURNAL OF MICROELECTROMECHANICAL SYSTEMS Guo, Z., Aboudi, U., Peumans, P., Howe, R. T., Chang, F. 2016; 25 (3): 524-532
  • Monitoring fatigue-induced transverse matrix cracks in laminated composites using built-in acousto-ultrasonic techniques STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Wilson, C. L., Chang, F. K. 2016; 15 (3): 335-350
  • Damage detection sensitivity characterization of acousto-ultrasound-based structural health monitoring techniques STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Janapati, V., Kopsaftopoulos, F., Li, F., Lee, S. J., Chang, F. 2016; 15 (2): 143-161
  • Bio-Inspired Stretchable Absolute Pressure Sensor Network. Sensors Guo, Y., Li, Y., Guo, Z., Kim, K., Chang, F., Wang, S. X. 2016; 16 (1)

    Abstract

    A bio-inspired absolute pressure sensor network has been developed. Absolute pressure sensors, distributed on multiple silicon islands, are connected as a network by stretchable polyimide wires. This sensor network, made on a 4'' wafer, has 77 nodes and can be mounted on various curved surfaces to cover an area up to 0.64 m × 0.64 m, which is 100 times larger than its original size. Due to Micro Electro-Mechanical system (MEMS) surface micromachining technology, ultrathin sensing nodes can be realized with thicknesses of less than 100 µm. Additionally, good linearity and high sensitivity (~14 mV/V/bar) have been achieved. Since the MEMS sensor process has also been well integrated with a flexible polymer substrate process, the entire sensor network can be fabricated in a time-efficient and cost-effective manner. Moreover, an accurate pressure contour can be obtained from the sensor network. Therefore, this absolute pressure sensor network holds significant promise for smart vehicle applications, especially for unmanned aerial vehicles.

    View details for DOI 10.3390/s16010055

    View details for PubMedID 26729134

    View details for PubMedCentralID PMC4732088

  • Electromagnetic Navigation Linear Displacement Transducer Based on Magnetic Field Gradient Technique IEEE TRANSACTIONS ON MAGNETICS Zhang, M., Or, S. W., Wang, S., Chang, F. 2015; 51 (11)
  • Load monitoring and compensation strategies for guided-waves based structural health monitoring using piezoelectric transducers JOURNAL OF SOUND AND VIBRATION Roy, S., Ladpli, P., Chang, F. 2015; 351: 206-220
  • Ultrasonic guided wave active sensing for monitoring of split failures in reinforced concrete STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Wu, F., Chan, H., Chang, F. 2015; 14 (5): 439-448
  • Linearly dispersive signal construction of Lamb waves with measured relative wavenumber curves SENSORS AND ACTUATORS A-PHYSICAL Cai, J., Yuan, S., Qing, X. P., Chang, F., Shi, L., Qiu, L. 2015; 221: 41-52
  • On-line updating Gaussian mixture model for aircraft wing spar damage evaluation under time-varying boundary condition SMART MATERIALS AND STRUCTURES Qiu, L., Yuan, S., Chang, F., Bao, Q., Mei, H. 2014; 23 (12)
  • Recent advancements and vision toward stretchable bio-inspired networks for intelligent structures STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Salowitz, N., Guo, Z., Roy, S., Nardari, R., Li, Y., Kim, S., Kopsaftopoulos, F., Chang, F. 2014; 13 (6): 609-620
  • Trends on research in structural health monitoring STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Guemes, A., Salowitz, N., Chang, F. 2014; 13 (6): 579-580
  • Microfabricated Expandable Sensor Networks for Intelligent Sensing Materials IEEE SENSORS JOURNAL Salowitz, N. P., Guo, Z., Kim, S., Li, Y., Lanzara, G., Chang, F. 2014; 14 (7): 2138-2144
  • A novel physics-based temperature compensation model for structural health monitoring using ultrasonic guided waves STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Roy, S., Lonkar, K., Janapati, V., Chang, F. 2014; 13 (3): 321-342
  • In situ damage classification for composite laminates using Gaussian discriminant analysis STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Larrosa, C., Lonkar, K., Chang, F. 2014; 13 (2): 190-204
  • Modeling of piezo-induced ultrasonic wave propagation in composite structures using layered solid spectral element STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Lonkar, K., Chang, F. 2014; 13 (1): 50-67
  • Bio-inspired stretchable network-based intelligent composites JOURNAL OF COMPOSITE MATERIALS Salowitz, N., Guo, Z., Li, Y., Kim, K., Lanzara, G., Chang, F. 2013; 47 (1): 97-105
  • Development of High Performance BS-PT Based Piezoelectric Transducer for Structural Health Monitoring of High-Temperature Polymer-Matrix Composite Structures Li, Y. -H., Kim, S. -J., Nardari, R., Oropeza, D., Chang, F. -K 2013
  • Screen Printed Piezoceramic Actuators/Sensors Microfabricated on Organic Films and Stretchable Networks Salowitz, N., Guo, Z., Kim, S. -J., Li, Y. -H, Lanzara, G., Chang, F. -K 2013
  • Monitoring Transverse Matrix Cracking in Composite Laminates Using Ultrasonic Guided Waves Larrosa, C., Chang, F. -K 2013
  • Structural damage detection using ultrasonic guided waves under varying ambient temperature and loading environments Roy, S., Ladpli, P., Lonkar, P., Chang, F. -K 2013
  • A vision on stretchable bio-inspired networks for intelligent structures Salowitz, N., Guo, Z., Roy, S., Nardari, R., Li, Y. -H, Kopsaftopoulos, F., Chang, F. 2013
  • Sensor Network Configuration Effect on Detection Sensitivity of an Acousto-Ultrasound-based Active SHM System Janapati, V., Kopsaftopoulos, F., Roy, S., Mueller, I., Lee, S., J., Ladpli, P., Chang, F. 2013
  • A structural health monitoring fastener for tracking fatigue crack growth in bolted metallic joints STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Rakow, A., Chang, F. 2012; 11 (3): 253-267
  • Bio-inspired intelligent sensing materials for fly-by-feel autonomous vehicles 11th IEEE Sensors Conference Salowitz, N., Guo, Z., Kim, S., Li, Y., Lanzara, G., Chang, F. IEEE. 2012: 363–365
  • Real-time prediction of impact-induced damage for composite structures based on failure analysis and efficient database methods Roy, S., Mueller, I., Janapati, V., Das, S., Chang, F. -K 2012
  • A Model-assisted Integrated Diagnostics for Structural Health Monitoring Lonkar, K., Janapati, V., Roy, S., Chang, F. -K 2012
  • Bio-inspired intelligent sensing materials for fly-by-feel autonomous vehicles Salowitz, N., Guo, Z., Kim, S., J., Li, Y. -H, Lanzara, G., Chang, F. -K 2012
  • Real time in-situ damage classification, quantification and diagnosis for composite structures Larrosa, C., Chang, F. -K 2012
  • Strain/Elongation Sensitive Metal-Coated Polyimide Microwires for Micro-Scaled Highly Expandable Sensor Networks Lanzara, G., Guo, Z., Salowitz, N., Chang, F. -K 2012
  • Design of Optimal Layout of Active Sensing Diagnostic Network for Achieving Highest Damage Detection Capability in Structures Janapati, V., Lonkar, K., Chang, F., K. 2012
  • STRUCTURAL HEALTH MONITORING OF HIGH TEMPERATURE COMPOSITES ASME International Mechanical Engineering Congress and Exposition (IMECE) Salowitz, N., Li, Y., Kim, S., Roy, S., Chang, F. AMER SOC MECHANICAL ENGINEERS. 2012: 273–280
  • Real-time prediction of impact-induced damage for composite structures based on failure analysis and efficient database methods Conference on Health Monitoring of Structural and Biological Systems Roy, S., Mueller, I., Janapati, V., Das, S., Chang, F. SPIE-INT SOC OPTICAL ENGINEERING. 2012

    View details for DOI 10.1117/12.917528

    View details for Web of Science ID 000304193700047

  • A dynamic crash model for energy absorption in braided composite materials - Part II: Implementation and verification JOURNAL OF COMPOSITE MATERIALS Flesher, N. D., Chang, F., Janapala, N. R., Starbuck, J. M. 2011; 45 (8): 867-882
  • A dynamic crash model for energy absorption in braided composite materials. Part I: Viscoplastic material model JOURNAL OF COMPOSITE MATERIALS Flesher, N. D., Chang, F., Janapala, N. R. 2011; 45 (8): 853-865
  • Bio-Inspired Smart Skin Based on Expandable Network Guo, Z., Kim, K., Lanzara, G., Salowitz, N., Peumans, P., Chang, F. -K 2011
  • Structural Health Monitoring SYSTEM HEALTH MANAGEMENT: WITH AEROSPACE APPLICATIONS Chang, F., Markmiller, J. C., Yang, J., Kim, Y., Johnson, S. B., Gormley, T. J., Kessler, S. S., Mott, C. D., PattersonHine, A., Reichard, K. M., Scandura, P. A. 2011: 419-428
  • Micro-Fabricated, Expandable Temperature Sensor Network for Macro-Scale Deployment in Composite Structures Guo, Z., Kim, K., Lanzara, G., Salowitz, N., Peumans, P., Chang, F. -K 2011
  • Physics Based Temperature Compensation Strategy for Structural Health Monitoring 8th International Workshop on Structural Health Monitoring Roy, S., Lonkar, K., JANAPATI, V., Chang, F. DESTECH PUBLICATIONS, INC. 2011: 1139–1149
  • A Robust Impact Force Determination Technique for Complex Structures Mueller, I., Vonnieda, K., Das, S., Chang, F. -K 2011
  • Accelerated aging experiments for prognostics of damage growth in composite materials Saxena, A., Goebel, K., Larrosa, C., Janapati, V., Roy, S., Chang, F. -K 2011
  • Development of a bio-inspired stretchable network for intelligent composites Salowitz, N., Guo, Z., Li, Y. -H, Kim, K., Lanzara, G., Chen, Y., Chang, F. 2011
  • On the Performance Quantification of Active Sensing SHM Systems using Model-assisted POD Methods Mueller, I., Janapati, V., Banerjee, S., Lonkar, K., Roy, S., Chang, F. -K 2011
  • Characterization of temperature, load and damage effects using piezo-electric transducer patches based on fuzzy clustering Lopes, V., Gonsalez, C., da Silva, S., Roy, S., Kode, K., Sunor, F., Chang, F. 2011
  • Development of SEM-based PESEA Code for Modeling PZT Induced Acousto-ultrasonic Waves Propagating in Metallic & Composite Structures Lonkar, K., Chang, F. -K 2011
  • High Temperature Intelligent Composites Li, Y. -H., Kim, S. -J., Salowitz, N., Roy, S., Larrosa, C., Janapati, V., Chang, F. 2011
  • Damage classification in composite laminates, matrix micro-cracking and delamination Larrosa, C., Lonkar, K., Shankar, S., Chang, F. -K 2011
  • In-situ damage assessment of composite laminates via active sensor networks Larrosa, C., Janapati, V., Roy, S., Chang, F. -K 2011
  • A Spider-Web-Like Highly Expandable Sensor Network for Multifunctional Materials ADVANCED MATERIALS Lanzara, G., Salowitz, N., Guo, Z., Chang, F. 2010; 22 (41): 4643-4648

    View details for DOI 10.1002/adma.201000661

    View details for Web of Science ID 000284002600014

    View details for PubMedID 20824665

  • Editorial-2009 Technology Review and Update: Selected Highlights from IWSHM 2009 STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Chang, F., Guemes, A. 2010; 9 (3): 197-198
  • Adhesive Layer Effects on PZT-induced Lamb Waves at Elevated Temperatures STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Ha, S., Lonkar, K., Mittal, A., Chang, F. 2010; 9 (3): 247-256
  • Prediction of Progressive Damage State at the Hot Spots using Statistical Estimation JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Banerjee, S., Qing, X. P., Beard, S., Chang, F. 2010; 21 (6): 595-605
  • Design of micro-scale highly expandable networks of polymer-based substrates for macro-scale applications SMART MATERIALS AND STRUCTURES Lanzara, G., Feng, J., Chang, F. 2010; 19 (4)
  • Adhesive interface layer effects in PZT-induced Lamb wave propagation SMART MATERIALS AND STRUCTURES Ha, S., Chang, F. 2010; 19 (2)
  • Sensor Network Optimization for a Passive Sensing Impact Detection Technique STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Markmiller, J. F., Chang, F. 2010; 9 (1): 25-39
  • The Needs for SHM Technology Classification Mueller, I., Chang, F. -K 2010
  • A Spider Web-Like Highly Expandable Sensor Network Advanced Materials Lanzara, G., Salowitz, N., Guo, Z., Chang, F. -K 2010; 41 (22): 44643-4648.
  • An Integrated Health Management System for Real-Time Impact Monitoring and Prediction of Impact-Induced Damage on Composite Structures Mueller, I., Das, S., Roy, S., Janapati, V., Vonnieda, K., Zhang, D., Chang, F. 2010
  • An Integrated Health Management System for Real-time Impact Monitoring and Prediction of Impact-Induced Damage on Composite Structures Conference on Health Monitoring of Structural and Biological Systems 2010 Mueller, I., Das, S., Roy, S., Janapati, V., Vonnieda, K., Zhang, D., Chang, F. SPIE-INT SOC OPTICAL ENGINEERING. 2010

    View details for DOI 10.1117/12.849667

    View details for Web of Science ID 000285545600044

  • Optimizing a spectral element for modeling PZT-induced Lamb wave propagation in thin plates SMART MATERIALS & STRUCTURES Ha, S., Chang, F. 2010; 19 (1)
  • Design and characterization of a carbon-nanotube-reinforced adhesive coating for piezoelectric ceramic discs SMART MATERIALS & STRUCTURES Lanzara, G., Chang, F. 2009; 18 (12)
  • Development of a real-time active pipeline integrity detection system SMART MATERIALS & STRUCTURES Qing, X. P., Beard, S., Shen, S. B., Banerjee, S., Bradley, I., Salama, M. M., Chang, F. 2009; 18 (11)
  • Influence of Interface Degradation on the Performance of Piezoelectric Actuators JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Lanzara, G., Yoon, Y., Kim, Y., Chang, F. 2009; 20 (14): 1699-1710
  • Monitoring Impact Events Using a System-Identification Method AIAA JOURNAL Park, J., Ha, S., Chang, F. 2009; 47 (9): 2011-2021

    View details for DOI 10.2514/1.34895

    View details for Web of Science ID 000269898800003

  • Optimal placement of sensors for sub-surface fatigue crack monitoring THEORETICAL AND APPLIED FRACTURE MECHANICS Teo, Y. H., Chiu, W. K., Chang, F. K., Rajic, N. 2009; 52 (1): 40-49
  • Damage Detection for Composite Laminate Plates with A Distributed Hybrid PZT/FBG Sensor Network JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Wu, Z., Qing, X. P., Chang, F. 2009; 20 (9): 1069-1077
  • A new type of plasma wakefield accelerator driven by magnetowaves PLASMA PHYSICS AND CONTROLLED FUSION Chen, P., Chang, F., Lin, G., Noble, R. J., Sydora, R. 2009; 51 (2)
  • The effects of structural variations on the health monitoring of composite structures International Workshop on Structural Assessment of Composite Structures Chiu, W. K., Tian, T., Chang, F. K. ELSEVIER SCI LTD. 2009: 121–40
  • An integrated health management and prognostic technology for composites airframe structures Mueller, I., Larrosa, C., Roy, S., Mittal, A., Lonkar, K., Chang, F. -K 2009
  • A robust structural health monitoring technique for airframe structures Mueller, I., Chang, F. -K, Roy, S., Mittal, A., Lonkar, K., Larrosa, C. 2009
  • An integrated diagnostic to prognostic SHM technology for structural health management Mueller, I., Larrosa, C., Roy, S., Chang, F. -K 2009
  • Model-Based Impact Monitoring by Inverse Methods using Particle Swarm Optimization Mueller, I., Chang, F. -K 2009
  • Adhesive Layer Effects on Temperature-sensitive Lamb Waves Induced by Surface-mounted PZT Acutators Ha, S., Mittal, A., Lonkar, K., Chang, F. -K 2009
  • SACL Activities in Structural Health Monitoring Guo, Z., Mueller, I., Lanzara, G., Janapala, N., Lonkar, K., Mittal, A., Chang, F. 2009
  • Design of Planar Electrodes for Multifunctional Piezoelectric Sensors Salowitz, N., Lanzara, G., Guo, Z., Rose, J., Chang, F. -K 2009
  • Multifunctional Sensor Nodes in Stretchable Network for Structural Health Monitoring Lanzara, G., Salowitz, N., Guo, Z., Chatterjee, D., Kim, K., Peumans, P., Chang, F. 2009
  • Health monitoring of bonded composite repair in bridge rehabilitation SMART MATERIALS AND STRUCTURES Wu, Z., Qing, X. P., Ghosh, K., Karbhar, V., Chang, F. 2008; 17 (4)
  • In vitro atherosclerotic plaque characterization by acoustic impedance monitoring, Part I: Sensor modeling, design, and fabrication JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Dugnani, R., Chang, F. K. 2008; 19 (7): 815-826
  • In vitro atherosclerotic plaque characterization by acoustic impedance monitoring, Part II: Experimentation and validation JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Dugnani, R., Chang, F. K. 2008; 19 (7): 827-835
  • Time-domain spectral element method for built-in piezoelectric-actuator-induced lamb wave propagation analysis AIAA JOURNAL Kim, Y., Ha, S., Chang, F. 2008; 46 (3): 591-600

    View details for DOI 10.2514/1.27046

    View details for Web of Science ID 000253403200006

  • Pitch-catch active sensing methods in structural health monitoring for aircraft structures STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Ihn, J., Chang, F. 2008; 7 (1): 5-19
  • A large area flexible expandable network for structural health monitoring Conference on Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems Lanzara, G., Feng, J., Chang, F. SPIE-INT SOC OPTICAL ENGINEERING. 2008

    View details for DOI 10.1117/12.781803

    View details for Web of Science ID 000257062100045

  • Design and experimental validation of a structural health monitoring fastener ASME International Mechanical Engineering Congress and Exposition Rakow, A., Chang, F. AMER SOC MECHANICAL ENGINEERS. 2008: 707–713
  • A potential link from damage diagnostics to health prognostics of composites through built-in sensors JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME Chang, F., Markmiller, J. F., Ihn, J., Cheng, K. Y. 2007; 129 (6): 718-729

    View details for DOI 10.1115/1.2730530

    View details for Web of Science ID 000250936900005

  • Energy absorption features of 3-D braided rectangular composite under different strain rates compressive loading AEROSPACE SCIENCE AND TECHNOLOGY Gu, B., Chang, F. 2007; 11 (7-8): 535-545
  • Built-in sensor network for structural health monitoring of composite structure JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Qing, X. P., Beard, S. J., Kumar, A., Ooi, T. K., Chang, F. 2007; 18 (1): 39-49
  • A new SMART sensing system for aerospace structures UNMANNED SYSTEMS TECHNOLOGY IX Zhang, D. C., Yu, P., Beard, S., Qing, P., Kumar, A., Chang, F. 2007; 6561

    View details for DOI 10.1117/12.720124

    View details for Web of Science ID 000248227700006

  • An approach to cost-effective, robust, large-area electronics using monolithic silicon IEEE International Electron Devices Meeting Huang, K., Dinyari, R., Lanzara, G., Kim, J. Y., Feng, J., Vancura, C., Chang, F., Peumans, P. IEEE. 2007: 217–220
  • Detection of bolt loosening in C-C composite thermal protection panels: I. Diagnostic principle SMART MATERIALS AND STRUCTURES Yang, J. Y., Chang, F. K. 2006; 15 (2): 581-590
  • Detection of bolt loosening in C-C composite thermal protection panels: II. Experimental verification SMART MATERIALS AND STRUCTURES Yang, J. K., Chang, F. K. 2006; 15 (2): 591-599
  • Debond detection using embedded piezoelectric elements in reinforced concrete structures - Part I: Experiment STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Wu, F., Chang, F. K. 2006; 5 (1): 5-15
  • Debond detection using embedded piezoelectric elements for reinforced concrete structures - Part II: Analysis and algorithm STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL Wu, F., Chang, F. K. 2006; 5 (1): 17-28
  • Structural health monitoring of composite repair patches in bridge rehabilitation Smart Structures and Materials 2006 Conference Wu, Z., Ghosh, K., Qing, X., Karbhari, V., Chang, F. SPIE-INT SOC OPTICAL ENGINEERING. 2006

    View details for DOI 10.1117/12.667177

    View details for Web of Science ID 000238486200067

  • A hybrid piezoelectric/fiber optic diagnostic system for structural health monitoring 1st International Conference on Structural Health Monitoring and Intelligent Infrastructure Qing, X. L., Kumar, A., Zhang, C., Gonzalez, I. F., Guo, G. P., Chang, F. K. IOP PUBLISHING LTD. 2005: S98–S103
  • Scattering of plate waves by a cylindrical inhomogeneity JOURNAL OF SOUND AND VIBRATION Wang, C. H., Chang, F. K. 2005; 282 (1-2): 429-451
  • Design of Active Structural Health Monitoring Systems for Aircraft and Spacecraft Structures DAMAGE PROGNOSIS: FOR AEROSPACE, CIVIL AND MECHANICAL SYSTEMS Chang, F., Ihn, J., Blaise, E., Inman, D. J., Farrar, C. R., Lopes, Steffen 2005: 323-341
  • Detection and monitoring of hidden fatigue crack growth using a built-in piezoelectric sensor/actuator network: I. Diagnostics SMART MATERIALS & STRUCTURES Ihn, J. B., Chang, F. K. 2004; 13 (3): 609-620
  • Detection and monitoring of hidden fatigue crack growth using a built-in piezoelectric sensor/actuator network: II. Validation using riveted joints and repair patches SMART MATERIALS & STRUCTURES Ihn, J. B., Chang, F. K. 2004; 13 (3): 621-630
  • A synthetic time-reversal imaging method for structural health monitoring SMART MATERIALS & STRUCTURES Wang, C. H., Rose, J. T., Chang, F. K. 2004; 13 (2): 415-423
  • Ferroelectric and piezoelectric properties of disk shape lead zirconate titanate thick films MATERIALS TRANSACTIONS Iijima, T., Ito, S., Matsuda, H., Dugnani, R., Chang, F. K. 2004; 45 (2): 233-235
  • Damage tolerance of notched composite laminates with reinforcing strips JOURNAL OF COMPOSITE MATERIALS Qing, X. L., Chang, F. K., Starnes, J. 2003; 37 (2): 111-128
  • Vibration analysis of delaminated composite beams and plates using a higher-order finite element INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES Hu, N., Fukunaga, H., Kameyama, M., Aramaki, Y., Chang, F. K. 2002; 44 (7): 1479-1503
  • Magneto-rheological fluid dampers for control of bridges ASME International Mechanical Engineering Congress and Exposition Gordaninejad, F., Saiidi, M., Hansen, B. C., Ericksen, E. O., Chang, F. K. SAGE PUBLICATIONS LTD. 2002: 167–80
  • Energy absorption of braided composite tubes INTERNATIONAL JOURNAL OF CRASHWORTHINESS Beard, S. J., Chang, F. K. 2002; 7 (2): 191-206
  • Design of braided composites for energy absorption JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS Beard, S., Chang, F. K. 2002; 15 (1): 3-12
  • Structural damage identification using piezoelectric sensors INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES Fukunaga, H., Hu, N., Chang, F. K. 2002; 39 (2): 393-418
  • The manufacture of composite structures with a built-in network of piezoceramics COMPOSITES SCIENCE AND TECHNOLOGY Lin, M., Chang, F. K. 2002; 62 (7-8): 919-939
  • The response of composite joints with bolt-clamping loads, Part II: Model verification JOURNAL OF COMPOSITE MATERIALS Sun, H. T., Chang, F. K., Qing, X. L. 2002; 36 (1): 69-92
  • The response of composite joints with bolt-clamping loads, Part 1: Model development JOURNAL OF COMPOSITE MATERIALS Sun, H. T., Chang, F. K., Qing, X. L. 2002; 36 (1): 47-67
  • Structural health monitoring from fiber-reinforced composites to steel-reinforced concrete European COST F3 Conference on System Identification and Structural Health Monitoring Wang, C. S., Wu, F., Chang, F. K. IOP PUBLISHING LTD. 2001: 548–52
  • Special issue on structural health monitoring - Preface SMART MATERIALS & STRUCTURES Guemes, A., Boller, C., Chang, F. K. 2001; 10 (3): U3-U3
  • Impact identification of stiffened composite panels: II. Implementation studies SMART MATERIALS & STRUCTURES Seydel, R., Chang, F. K. 2001; 10 (2): 370-379
  • Impact identification of stiffened composite panels: I. System development SMART MATERIALS & STRUCTURES Seydel, R., Chang, F. K. 2001; 10 (2): 354-369
  • Characterization of matrix crack-induced laminate failure - Part II: Analysis and verifications JOURNAL OF COMPOSITE MATERIALS Johnson, P., Chang, F. K. 2001; 35 (22): 2037-2074
  • Characterization of matrix crack-induced laminate failure - Part I: Experiments JOURNAL OF COMPOSITE MATERIALS Johnson, P., Chang, F. K. 2001; 35 (22): 2009-2035
  • Modelling of splitting and delamination in notched cross-ply laminates COMPOSITES SCIENCE AND TECHNOLOGY Wisnom, M. R., Chang, F. K. 2000; 60 (15): 2849-2856
  • Experimental study on clamping effects on the tensile strength of composite plates with a bolt-filled hole COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING Yan, Y., Wen, W. D., Chang, F. K., Shyprykevich, P. 1999; 30 (10): 1215-1229
  • Identifying impacts in composite plates with piezoelectric strain sensors, Part II: Experiment JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Tracy, M., Chang, F. K. 1998; 9 (11): 929-937
  • Structural health monitoring JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Pines, D. J., Chang, F. K. 1998; 9 (11): 875-875
  • Identifying impacts in composite plates with piezoelectric strain sensors, Part I: Theory JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Tracy, M., Chang, F. K. 1998; 9 (11): 920-928
  • Composite hip prosthesis design .2. Simulation JOURNAL OF BIOMEDICAL MATERIALS RESEARCH Yildiz, H., Chang, F. K., Goodman, S. 1998; 39 (1): 102-119

    Abstract

    An investigation was performed to study the mechanical performance of fiber-reinforced composite hip prostheses. In Part I of the study, a three-dimensional finite element code was developed for analyzing a composite hip prosthesis in a femur. The material properties of the composite were treated as anisotropic and inhomogeneous while the properties of the femoral bone were treated as anisotropic and homogeneous. All the materials were assumed to behave linear-elastically. Thermoplastic graphite/PEEK material was selected for the study. No slippage was assumed at the interface between the implant and the surrounding femoral bone. In Part II, numerical simulations were performed using the code to study the performance of a composite prosthesis in the femur. The stress/strain distributions, micromotions, and strain energy density of the surrounding femoral bone were evaluated and found to be related to initial fixation and long-term stability of the prosthesis in the femur. Numerous fiber orientations were studied, and the results of the calculations were compared with those generated from a prosthesis made of cobalt chrome and Ti-6Al-4V titanium alloys. Based on the analysis, it was shown that compared to conventional metallic implants more favorable stresses and deformations could be generated in the femur using composite implants. In addition, by changing fiber orientations according to femoral loads, a composite implant could be designed specifically for the left or the right femur.

    View details for PubMedID 9429102

  • Composite hip prosthesis design .1. Analysis JOURNAL OF BIOMEDICAL MATERIALS RESEARCH Yildiz, H., Ha, S. K., Chang, F. K. 1998; 39 (1): 92-101

    Abstract

    An investigation was performed to study the mechanical performance of fiber-reinforced composite hip prostheses in a femur. The main objective of the study was to evaluate the effect of fiber orientation of a composite femoral implant on the response of the surrounding femoral bone. A three-dimensional finite element analysis was developed for analyzing a composite implant in the femur. A three-dimensional composite element was proposed to take into account ply drop-off due to a change of cross-section of the composite implant. The element could accommodate multidirectional layers and tapered composites. The material properties of the composite were treated as anisotropic and inhomogeneous while the properties of femoral bone were treated as anisotropic and homogenous. All the materials were assumed to behave linear-elastically. The thermoplastic graphite/PEEK material system was selected for the study. In this presentation, as the first part of the study, the development of the finite element analysis will be described. Numerical calculations were generated and compared with existing data and numerical results available from studies related to metal hip prostheses in the literature. Experiments on the composite hip implants were also conducted for further verification of the analysis and the computer simulations. In Part II, using the finite element code, an extensive study was performed to evaluate the stress/strain distributions, micromotions, and strain-energy density of the surrounding femoral bone, which have been related to initial fixation and long-term stability of the prosthesis in a femoral bone. Numerous fiber orientations were studied, and results of the calculations were compared with those generated by the prosthesis made of cobalt alloy and titanium alloy.

    View details for Web of Science ID 000070995300012

    View details for PubMedID 9429101

  • Active damage detection in filament wound composite tubes using built-in sensors and actuators JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Beard, S., Chang, F. K. 1997; 8 (10): 891-897
  • Identification of impact force and location using distributed sensors AIAA JOURNAL Choi, K. Y., Chang, F. K. 1996; 34 (1): 136-142
  • Bearing failure of bolted composite joints .1. Experimental characterization JOURNAL OF COMPOSITE MATERIALS Wang, H. S., Hung, C. L., Chang, F. K. 1996; 30 (12): 1284-1313
  • Strength envelope of bolted composite joints under bypass loads JOURNAL OF COMPOSITE MATERIALS Hung, C. L., Chang, F. K. 1996; 30 (13): 1402-1435
  • Bearing failure of bolted composite joints .2. Model and verification JOURNAL OF COMPOSITE MATERIALS Hung, C. L., Chang, F. K. 1996; 30 (12): 1359-1400
  • IDENTIFYING DELAMINATION IN COMPOSITE BEAMS USING BUILT-IN PIEZOELECTRICS .1. EXPERIMENTS AND ANALYSIS JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Keilers, C. H., Chang, F. K. 1995; 6 (5): 649-663
  • IDENTIFYING DELAMINATION IN COMPOSITE BEAMS USING BUILT-IN PIEZOELECTRICS .2. AN IDENTIFICATION METHOD JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES Keilers, C. H., Chang, F. K. 1995; 6 (5): 664-672
  • COMPOSITE PANELS CONTAINING MULTIPLE THROUGH-THE-WIDTH DELAMINATIONS AND SUBJECTED TO COMPRESSION .1. ANALYSIS COMPOSITE STRUCTURES KUTLU, Z., Chang, F. K. 1995; 31 (4): 273-296
  • COMPOSITE PANELS CONTAINING MULTIPLE THROUGH-THE-WIDTH DELAMINATIONS AND SUBJECTED TO COMPRESSION .2. EXPERIMENTS AND VERIFICATION COMPOSITE STRUCTURES KUTLU, Z., Chang, F. K. 1995; 31 (4): 297-314
  • PREDICTING SCALING EFFECT ON THE NOTCHED STRENGTH OF PREPREG AND FIBER TOW-PLACED LAMINATED COMPOSITES JOURNAL OF COMPOSITE MATERIALS Shahid, I., Sun, H. T., Chang, F. K. 1995; 29 (8): 1063-1095
  • AN ACCUMULATIVE DAMAGE MODEL FOR TENSILE AND SHEAR FAILURES OF LAMINATED COMPOSITE PLATES JOURNAL OF COMPOSITE MATERIALS Shahid, I., Chang, F. K. 1995; 29 (7): 926-981
  • MATRIX CRACKING EFFECT ON DELAMINATION GROWTH IN COMPOSITE LAMINATES INDUCED BY A SPHERICAL INDENTER JOURNAL OF COMPOSITE MATERIALS Liu, S., Chang, F. K. 1994; 28 (10): 940-977
  • MATRIX CRACKING AND DELAMINATION IN LAMINATED COMPOSITE BEAMS SUBJECTED TO A TRANSVERSE CONCENTRATED LINE LOAD JOURNAL OF COMPOSITE MATERIALS Sheng, L., KUTLU, Z., Chang, F. K. 1993; 27 (5): 436-470
  • FINITE-ELEMENT ANALYSIS OF COMPOSITE STRUCTURES CONTAINING DISTRIBUTED PIEZOCERAMIC SENSORS AND ACTUATORS AIAA JOURNAL Ha, S. K., KEILERS, C., Chang, F. K. 1992; 30 (3): 772-780
  • MODELING COMPRESSION FAILURE OF LAMINATED COMPOSITES CONTAINING MULTIPLE THROUGH-THE-WIDTH DELAMINATIONS JOURNAL OF COMPOSITE MATERIALS KUTLU, Z., Chang, F. K. 1992; 26 (3): 350-387
  • EFFECT OF LAMINATE CONFIGURATION AND IMPACTORS MASS ON THE INITIAL IMPACT DAMAGE OF GRAPHITE EPOXY COMPOSITE PLATES DUE TO LINE-LOADING IMPACT JOURNAL OF COMPOSITE MATERIALS Choi, H. Y., Wang, H. S., Chang, F. K. 1992; 26 (6): 804-827
  • A MODEL FOR PREDICTING DAMAGE IN GRAPHITE EPOXY LAMINATED COMPOSITES RESULTING FROM LOW-VELOCITY POINT IMPACT JOURNAL OF COMPOSITE MATERIALS Choi, H. Y., Chang, F. K. 1992; 26 (14): 2134-2169
  • IMPACT DAMAGE RESISTANCE OF GRAPHITE EPOXY LAMINATED COMPOSITES POLYMER COMPOSITES - 90 CONF Choi, H. Y., Chang, F. K. SOC PLASTICS ENG INC. 1991: 1294–1300
  • A NEW APPROACH TOWARD UNDERSTANDING DAMAGE MECHANISMS AND MECHANICS OF LAMINATED COMPOSITES DUE TO LOW-VELOCITY IMPACT .2. ANALYSIS JOURNAL OF COMPOSITE MATERIALS Choi, H. Y., WU, H. Y., Chang, F. K. 1991; 25 (8): 1012-1038
  • A NEW APPROACH TOWARD UNDERSTANDING DAMAGE MECHANISMS AND MECHANICS OF LAMINATED COMPOSITES DUE TO LOW-VELOCITY IMPACT .1. EXPERIMENTS JOURNAL OF COMPOSITE MATERIALS Choi, H. Y., DOWNS, R. J., Chang, F. K. 1991; 25 (8): 992-1011
  • MODELING THE VISCOPLASTIC BEHAVIOR OF FIBER-REINFORCED THERMOPLASTIC MATRIX COMPOSITES AT ELEVATED-TEMPERATURES JOURNAL OF COMPOSITE MATERIALS Ha, S. K., Wang, Q. L., Chang, F. K. 1991; 25 (4): 334-374
  • DAMAGE TOLERANCE OF LAMINATED COMPOSITES CONTAINING AN OPEN HOLE AND SUBJECTED TO TENSILE LOADINGS JOURNAL OF COMPOSITE MATERIALS Chang, K. Y., Liu, S., Chang, F. K. 1991; 25 (3): 274-301
  • DAMAGE TOLERANCE OF LAMINATED COMPOSITES CONTAINING AN OPEN HOLE AND SUBJECTED TO COMPRESSIVE LOADINGS .1. ANALYSIS JOURNAL OF COMPOSITE MATERIALS Chang, F. K., Lessard, L. B. 1991; 25 (1): 2-43
  • DAMAGE TOLERANCE OF LAMINATED COMPOSITES CONTAINING AN OPEN HOLE AND SUBJECTED TO COMPRESSIVE LOADINGS .2. EXPERIMENT JOURNAL OF COMPOSITE MATERIALS Lessard, L. B., Chang, F. K. 1991; 25 (1): 44-64
  • EFFECT OF LOAD DISTRIBUTION ON THE FIBER BUCKLING STRENGTH OF UNIDIRECTIONAL COMPOSITES JOURNAL OF COMPOSITE MATERIALS Lessard, L. B., Chang, F. K. 1991; 25 (1): 65-87
  • STUDY ON IMPACT DAMAGE IN LAMINATED COMPOSITES 1989 ARMY SYMP ON SOLID MECHANICS : MECHANICS OF ENGINEERED MATERIALS AND APPLICATIONS Chang, F. K., Choi, H. Y., Jeng, S. T. ELSEVIER SCIENCE BV. 1990: 83–95
  • ANALYSIS OF THICK LAMINATED COMPOSITES JOURNAL OF COMPOSITE MATERIALS Chang, F. K., Perez, J. L., Chang, K. Y. 1990; 24 (8): 801-822
  • DELAMINATION EFFECTS ON COMPOSITE SHELLS JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME Chang, F. K., KUTLU, Z. 1990; 112 (3): 336-340
  • STIFFNESS AND STRENGTH TAILORING OF A HIP-PROSTHESIS MADE OF ADVANCED COMPOSITE-MATERIALS JOURNAL OF BIOMEDICAL MATERIALS RESEARCH Chang, F. K., Perez, J. L., Davidson, J. A. 1990; 24 (7): 873-899

    Abstract

    This work is concerned with the design of hip prostheses using advanced fiber reinforced composite materials. The major focus of the study is to evaluate how the stiffness and strength of composite hip prostheses can be affected by variations in ply orientation and stacking sequence for a selected manufacturing method. This investigation involved both analytical and experimental work. An analytical model was developed which consists of a stress analysis and a failure analysis. A finite element program was developed during the course of the investigation for analyzing stresses, strains, and deformations of composite stems with a simplified configuration. Failure and mode of failure were predicted by appropriately selected failure criteria. Experiments were also performed on T300/976 graphite/epoxy composites to verify the analysis and the computer calculations. Both testing and analysis accounted for the various combinations of in-plane and out-of-plane (torsion) loading that can act on the prosthetic hip. Simplified composite stems with a 120 layer thickness were fabricated and tested. An excellent agreement was found between the measured strain data and the numerical calculations. Using the program, parametric studies were performed. It was found that an optimal design of hip stems can be achieved by using advanced fiber-reinforced composite materials, but great care must be taken when selecting the appropriate ply orientation and stacking sequence for a chosen fabrication method.

    View details for Web of Science ID A1990DK01300006

    View details for PubMedID 2398076

  • CHARACTERIZATION OF IMPACT DAMAGE IN LAMINATED COMPOSITES SAMPE JOURNAL Chang, F. K., Choi, H. Y., Jeng, S. T. 1990; 26 (1): 18-25
  • STUDY ON THE CRUSHING RESPONSE OF CYLINDRICAL COMPOSITE SHELLS SUBJECTED TO TRANSVERSE LOADING JOURNAL OF COMPOSITES TECHNOLOGY & RESEARCH Chang, F. K., KUTLU, Z. 1990; 12 (4): 239-244
  • PREDICTING MODULI AND STRENGTHS REDUCTION OF UNIDIRECTIONAL GRAPHITE EPOXY COMPOSITES DUE TO HYGROTHERMAL EFFECTS JOURNAL OF REINFORCED PLASTICS AND COMPOSITES Chang, F. K., Shahid, I., ENGDAHL, R. A. 1989; 8 (2): 106-132
  • STRENGTH AND RESPONSE OF CYLINDRICAL COMPOSITE SHELLS SUBJECTED TO OUT-OF-PLANE LOADINGS JOURNAL OF COMPOSITE MATERIALS Chang, F. K., KUTLU, Z. 1989; 23 (1): 11-31
  • TRANSIENT DYNAMIC ANALYSIS OF LAMINATED COMPOSITE PLATES SUBJECTED TO TRANSVERSE IMPACT COMPUTERS & STRUCTURES WU, H. Y., Chang, F. K. 1989; 31 (3): 453-466
  • MODELING OF UNIDIRECTIONAL PREFORMED COMPOSITES JOURNAL OF REINFORCED PLASTICS AND COMPOSITES Chang, F. K., Chang, K. Y., Engdahl, R. 1988; 7 (6): 582-600
  • COMPRESSION RESPONSE OF LAMINATED COMPOSITES CONTAINING AN OPEN HOLE SAMPE QUARTERLY-SOCIETY FOR THE ADVANCEMENT OF MATERIAL AND PROCESS ENGINEERING Chang, F. K., Lessard, L., Tang, J. M. 1988; 19 (4): 46-51
  • THE EFFECT OF TESTING METHODS ON THE SHEAR-STRENGTH DISTRIBUTION IN LAMINATED COMPOSITES JOURNAL OF REINFORCED PLASTICS AND COMPOSITES Chang, F. K., Tang, J. M., Peterson, D. G. 1987; 6 (4): 304-318
  • A PROGRESSIVE DAMAGE MODEL FOR LAMINATED COMPOSITES CONTAINING STRESS-CONCENTRATIONS JOURNAL OF COMPOSITE MATERIALS Chang, F. K., Chang, K. Y. 1987; 21 (9): 834-855
  • POST-FAILURE ANALYSIS OF BOLTED COMPOSITE JOINTS IN TENSION OR SHEAR-OUT MODE FAILURE JOURNAL OF COMPOSITE MATERIALS Chang, F. K., Chang, K. Y. 1987; 21 (9): 809-833
  • THE INSITU PLY SHEARSTRENGTH DISTRIBUTIONS IN GRAPHITE - EPOXY LAMINATED COMPOSITES JOURNAL OF COMPOSITE MATERIALS Chang, F. K., Chen, M. H. 1987; 21 (8): 708-733
  • THE STRENGTHS OF FIBER REINFORCED COMPOSITE BENDS JOURNAL OF COMPOSITE MATERIALS Chang, F. K., Springer, G. S. 1986; 20 (1): 30-45
  • EFFECTS OF PARTIAL CLOSURE AND FRICTION ON A RADIAL CRACK EMANATING FROM A CIRCULAR HOLE INTERNATIONAL JOURNAL OF FRACTURE COMNINOU, M., Chang, F. K. 1985; 28 (1): 29-36
  • DESIGN OF COMPOSITE LAMINATES CONTAINING PIN LOADED HOLES JOURNAL OF COMPOSITE MATERIALS Chang, F. K., Scott, R. A., Springer, G. S. 1984; 18 (3): 279-289
  • FAILURE STRENGTH OF NONLINEARLY ELASTIC COMPOSITE LAMINATES CONTAINING A PIN LOADED HOLE JOURNAL OF COMPOSITE MATERIALS Chang, F. K., Scott, R. A., Springer, G. S. 1984; 18 (5): 464-477
  • FAILURE OF COMPOSITE LAMINATES CONTAINING PIN LOADED HOLES - METHOD OF SOLUTION JOURNAL OF COMPOSITE MATERIALS Chang, F. K., Scott, R. A., Springer, G. S. 1984; 18 (3): 255-278
  • THE EFFECT OF LAMINATE CONFIGURATION ON CHARACTERISTIC LENGTHS AND RAIL SHEAR-STRENGTH JOURNAL OF COMPOSITE MATERIALS Chang, F. K., Scott, R. A., Springer, G. S. 1984; 18 (3): 290-296