SEDL / STP / STP1003-EB / STP10026S

A Test Method to Measure the Response of Composite Materials Under Reversed Cyclic Loads

Bakis, CE
Research associate, instructor, and professor, Virginia Polytechnic Institute and State University, Blacksburg, VA

Simonds, RA
Research associate, instructor, and professor, Virginia Polytechnic Institute and State University, Blacksburg, VA

Stinchcomb, WW
Research associate, instructor, and professor, Virginia Polytechnic Institute and State University, Blacksburg, VA

Pages: 14    Published: Jan 1989

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Abstract

A test method to measure the response of composite materials under reversed cyclic loads is described. The method approximates the long-term response of a component by permitting the composite specimen to respond to the imposed loads and fail in an unconstrained mode rather than in a constrained mode. The method has been successfully used for the reversed cyclic loading of unnotched and notched graphite/epoxy and graphite/PEEK laminates of various stacking sequences. Included in the paper are monotonic tensile and compressive stiffness and strength data at several points in the fatigue lifetime and damage development information obtained via X-ray radiography for quasi-isotropic T300/5208 and AS4/PEEK laminates with unloaded circular holes.