STUDIES OF STRESS CONCENTRATION BY USING SPECIAL HYBRID STRESS ELEMENTS

The stresses around rectangular holes of rounded corners and rounded notches are analysed by using the combination of three kinds of three-dimensional special hybrid stress nite elements. One kind of three- dimensional hybrid stress nite element with a traction-free inclined surface has been developed here based on an extended Hellinger{Reissner principle by a rational approach. Other two kinds of 12-node three- dimensional hybrid stress elements with a traction-free cylindrical surface and a traction-free perpendicular surface, respectively, were derived based on the Hellinger{Reissner principle. Examples have indicated that the combination of these special solid elements is far superior in predicting the stress concentration factors, the distributions of circumferential stresses and normal stresses for solids with holes and notches