Elastic Stress and Strain Distribution in Deep Composite Beams.

The distributions of stresses and strains in deep composite beams subjected to bending with shear, have been examined. Initially photoelastic models v/ere used. A method of manufacturing suitable photoelastic models is described, and a method of separating stresses, using a modified form of the well known shear difference method, has been developed. This enables a digital computer to be used to carry out the many calculations required to determine the separate stresses. This method is fully described and the computer program presented as an appendix, A number of finite element programs have been written, and a sample program, using elements which allow linear variations of strain within them is presented as an appendix so that other investigators may make use of it. These finite element programs have been used to determine the distribution of stresses and strains in five different beams. Using the maximum tensile strain as the criteria of fracture for the matrix, crack patterns have been developed in each of the five beams. At each stage of crack development, the distributions of stresses and strains have been determined, and for some representative samples, these distributions are presented in a graphical form