University of Illinois at Urbana-Champaign, Urbana, IL
Ford Motor Company, Dearborn, MI
Pages: 10 Published: Jan 2000
An experimental study of the strength and failure behavior of an orthotropic G-10 glass fiber-reinforced epoxy laminate has been conducted. Tubular specimens were loaded in combinations of tension, compression, torsion, internal pressure, and external pressure to produce a variety of stress states. Previous work involved the loading of two simultaneously applied in-plane stresses. This investigation furthers the previous work by simultaneously applying three in-plane stresses. One interesting observation from this work is that combined axial compression and torsion loading results in a much lower failure strength than combined hoop compression and torsion even though the stress state is identical. For the same torsion stress, axial compression is more damaging than hoop compression because torsion loading rotates fibers aligned in the axial direction to accommodate the shear strains. Hoop fibers do not rotate and remain aligned in the compressive loading direction. A simple failure mode dependent maximum stress theory that considers low-energy compressive failure modes such as delamination and fiber buckling provides a reasonable fit to the experimental data.
composite strength, multiaxial loading, failure theories
Paper ID: STP13494S