Center for Advanced Materials of High Quality Dynamic Performance (Center ofExcellence) (Research)

摘要

Since October, 1986 the Center for Advanced Materials of High Quality DynamicPerformance has been established at the University of California, San Diego, by the Army Research Office, Durham, as part of DoD's University Research Initiative. This phase of this URI continued to June, 1992 (including a no-cost extension). This multidisclipinary Center focused on a coordinated macroscopic and microscopic experimental and theoretical characterization and constitutive modeling of the mechanical response and failure modes of advanced materials at ultrahigh strain rates. The Center has developed unique state-of-the-art instrumentation for controlled mechanical testing of metals, metal-matrix composites, ceramics, and ceramic composites, over the full range of strain rates from quasi-static to greater than 10 to the 6th/s, and temperatures from -200 deg C to greater than 1000 deg C with complete time-resolved data acquisition systems. Among the Center's major contributions are novel dynamic recovery techniques invented for split Hopkinson bars, normal and oblique plate impact experiments, and laser-induced compression/tension involving pulses of extremely short duration and high amplitude. These are expected Sc impact the nature of future high strain rate testing. This is paralleled by physically-based micromechanical models of high strain rate plastic flow of metals, microcracking, phase transformation, and damage evolution in advanced an their composites. A breakthrough has been made in computational algorithms, which provides a powerful tool for constitutive computational modeling of the nonlinear response and failure modes of ductile materials. (MM).