UCLA Extension

Damage Tolerance and Durability of Composite Materials

Composite structures must be capable of performing their function throughout a specified lifetime while meeting safety and economic objectives. These structures are exposed to a series of events that include loading, environment, and damage threats. These events, either individually or cumulatively, can cause structural degradation, which—in turn—can affect the ability of the structure to perform its function.

This course is aimed at providing an in-depth understanding of the mechanisms of composite degradation and analytical tools to predict response to damage threats in service, including fatigue loading, impact damage and environmental effects.

Coordinator and Lecturer

Jenn-Ming Yang, PhD, Professor and Chair, Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, UCLA. Professor Yang has over 25 years of research and teaching experience in fiber-reinforced composite materials for aerospace structural and propulsional applications. He has performed research in composite processing and process simulation, microstructural characterization and mechanical testing, micromechanical modeling, and life prediction. He received the Presidential Young Investigator’s Award from the National Science Foundation in 1990 and has been the PI/Co-PI in various federal funded research programs, including NSF, FAA, AFOSR, and NASA. Professor Yang has published over 180 technical papers in composite materials and high-temperature materials for aerospace structures. He received his PhD degree from the University of Delaware in 1986.

Course Program

Overview of Damage Tolerance and Durability of Composites

  • Damage modes
  • Failure modes
  • Aircraft damage tolerance
  • Methods for compliance to aviation regulations

Micromechanical Analysis of Composite Stiffness and Strength

  • Tensile strength of unidirectional composites
  • Factors affecting composite strength
  • Compressive strength
  • Transverse strength and shear strength
  • Strength under multiaxial loading

Stiffness Evolution

  • Stiffness change due to matrix cracking
  • Time-dependent stiffness change
  • Temperature-dependent stiffness change

Damage Initiation

  • Life factor approach
  • Load enhancement factor approach
  • Ultimate strength approach

Damage Growth under Fatigue Loading

  • Damage accumulation
  • Progressive failure
  • Life prediction methodology

Residual Strength

  • Residual strength under long-term loading
  • Strength evolution due to damage accumulation
  • Residual strength with impact damage

Analysis Methods

  • Large through-penetration damage
  • Single delamination and disbond
  • Impact damages
  • Cuts and gouges

Design Guidelines and Application Examples


For more information contact the Short Course Program Office:
shortcourses@uclaextension.edu | (310) 825-3344 | fax (310) 206-2815

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