Relating stress concentrations in triangular steel bridge piers to simple beam models

Abstract

Triangular piers integrate both support surface for bearings and lateral stiffness to resist horizontal force. It is generally known that in the triangle’s corner large stress concentrations may appear. Therefore curved transitions are provided at these locations. To determine these stress concentrations the use of highly dense FE-models and indeed also engineering judgement, is needed. The latter applies to most software packages. On the other hand, one might consider to use simple beam elements, the axes coinciding with the real pier axes. In doing this, the stress concentrations will be missed and unsafe design is the result. The main aim of the research is to compare the results of an equivalent beam model to elaborate shell element models, which include the necessary transition curves. For each type of external force and rounding parameters the stress concentration factor for the undisturbed cross-sections is established. The work is presently in progress and the first results show definitely plausible factors. However, for small stress magnitude, the results are less convincing.