Elasto-Plastic Analysis of Perforated Plates Containing Triangular Penetration Patterns of 10 Percent Ligament Efficiency

The finite element method is utilized to obtain the elasto-plastic stress and strain fields in a perforated plate made of a work-hardening material. The perforated plate contains penetrations arranged in a triangular pattern with a ligament efficiency of 10 percent and is considered to be in a state of plane stress. Stress distributions as well as strain concentration factors are presented for the two orthogonal uniaxial and the pure shear load cases. Effective elasto-plastic equivalent solid plate properties are presented in terms of Hill’s anisotropic deformation plasticity theory. The localized stress and plastic strain distributions are discussed in terms of the work-hardening characteristics of the material. Conclusions are drawn relevant to the plastic design and analysis of perforated plates.