Inelastic post-buckling of columns

The concept of integrating through paper thickness to account for the stress reversal has been extensively applied before for the optimum design of slender cantilever columns. In this the earlier procedure of integrating through the thickness as indicated by the present authors, is used to determine the axial load and bending moment that each section can carry, and this is further used to compute the state of deformation in the structure. This indirect numerical iterative analysis allows the post-buckling behavior of a structure for nonlinearly elastic material to be determined as function of the parameters in the stress-strain laws

Convenient construction of tetrahedral finite elements for the quasi-harmonic equation

It is shown that in the finite-element formulation of the general quasi-harmonic equation using tetrahedral elements, for every member of the element family there exists just one numerical universal matrix indpendent of the size, shape and material properties of the element. Thus the element matrix is conveniently constructed by manipulating this single matrix along with a set of reverse sequence codes at the same time accounting for the size, shape and material properties in a simple manner