Research Assistant, Penn State University, University Park, PA
Associate Professor, Penn State University, University Park, PA
Pages: 18 Published: Jan 2003
The effect that various loads have on a 6092/SiC/17.5p-T6 particulate reinforced aluminum composite is determined. In addition to the mechanical response from tensile, compressive, and shear loading, yield loci in the axial-shear stress plane are constructed using axial-torsional loading of a thin-walled tube. Yield loci are determined by multiple yield probes of a single specimen using a 40 × 10-6 equivalent offset strain definition of yielding. Cyclic tensile straining to increasingly higher amplitudes indicated a modulus reduction of 16% prior to fracture, strongly suggesting accumulation of internal damage, but no change in the elastic Poisson's ratio was observed. Cyclic compressive loading resulted in no observable change in modulus. Cyclic shear loading led to a minimal shear modulus reduction of approximately 6%. The initial yield locus in the axial-shear stress plane had an eccentricity in the compressive stress direction that is known as a strength differential. The strength-differential was measured to be 55% and is believed to be associated with thermal residual stresses from heat treatment. After shear prestraining subsequent yield loci were constructed. Hardening was observed to be primarily kinematic.
yield surface, discontinuously reinforced aluminum, internal damage
Paper ID: STP38416S