STP 1357 describes worldwide recent developments on this topicand examines their practical applications. It also identifiesimportant unsolved fundamental problems. 18 peer-reviewed papersare grouped under the subheadings of Polymers and Composites.

Polymers covers:
• Chemical and Physical Aging
• Nonlinear Viscoelasticity and Iscoplasticty.

Composites addresses:
• Effect of Physical Aging on Time-Dependent Behavior
• Multiaxial Nonlinear Effect
• Compressive Behavior
• Nonlinear Viscoelasticity and Viscoplasticty
• Failure and Failure Mechanisms
• Hygrothermal Effects
• Durability Accelerated Strength Testing

Audience: Engineers and researchers who are interested indurability of composite materials; specific issues of timedependent and non-linear behavior; and the mechanics ofcomposites.