Analytical Investigation of Stress Concentrations Due to Holes in Fiber Reinforced Plastic Laminated Plates,Three-Dimensional Models.

摘要

A three-dimensional analysis for the stress distributions around a hole in a laminated plate is presented. The method of stress analysis is based on a complementary energy formulation with three-dimensional equilibrium finite elements. Three Maxwell stress functions are associated with each element. Finite element representations for the stress functions include positive and negative powers of the radial coordinate, r. This representation was found to give better stress solutions than the conventional representations with only positive powers of r. Numerical verification checks of the analysis for two-dimensional problems are presented. Three-dimensional finite element solutions are presented for four-and six-layered plates with symmetric lay-up angles. Material properties representing boron/epoxy laminas are used. Problems are selected to show the influence of laminate stacking sequence on the transverse normal and shear stresses around the hole. Stresses obtained from two-dimensional effective modulus representations are compared with three-dimensional results. (Author)