Locations of optimal stress points in higher-order elements

The locations of optimal stress points in Lagrangian and serendipity elemen ts are determined by using the symbolic mathematical tool MATHEMATICA(C). I t is found that, for the Lagrange family of elements of order more than two , the co-ordinates of optimal stress points slightly differ from those of t he reduced Gauss integration points. Some of the serendipity family of elem ents have either none or only one optimal stress point at the element centr e. Thus, when using higher-order elements in the p- or hp-version, it is mo re desirable to employ the Lagrange family of elements. Copyright (C) 1999 John Wiley & Sons, Ltd.