Significance of Strain Hardening and Strain Rate Effects on the Transient Response of Elastic-Plastic Spherical Shells

摘要

Formulae describing the transient response of uniformly loaded thin spherical shells governed by elastic-plastic material laws are developed. It is shown that realistic values of material strain hardening and strain rate sensitivity (rate-dependent yield surface) have a significant effect on both dynamic and final shell deflections. The corresponding rigid-plastic solution is developed and compared to the elastic-plastic solution. Peak deflections are found to agree to within 20 percent for ratios of plastic-to-elastic energy greater than 3. A numerical solution of the corresponding problem with a strain-rate-dependent tangent modulus indicates that the static tangent modulus is generally sufficiently accurate for structural calculations. (Author)