Some properties of linear strain triangles and optimal finite element models

A detailed study of the linear strain triangle (LST), which is very applicable in plane stress finite element analysis, is presented. Based on analytical stiffnesses, it is shown that the LST stiffnesses are easily obtainable from the stiffnesses of the corresponding simple constant strain triangle (CST). The optimization of finite element models is related to the configuration of the elements, and this analysis is also based upon the LST element. A procedure for changing to an improved finite element model is presented which does not require re-analysis. Several examples are discussed.