弾塑性接合要素のトラス置換による定式化 : 有効強度理論の一応用例

抄録

The purpose of this paper is to formulate a two-dimensional elastic-plastic joint element through three truss elements. The joint element consists of three members forming a truss structure : one vertical and two diagonal elements with different stress strain relations. The yielding condition of the joint element is determined by two factors : one takes account of possible combination in the order of the members turning to the plastic phase, and the other gives appropriate properties of the three elements in comparison with experiments or theories : Young's modulus, compressive strength and tensile one. The present element is much simpler than others to express a discontinuous plane in the plastic phase based on mathematical formulations. Results of numerical analyses are as follows : 1) In case of plain concrete under combined stress, the yielding condition from the present theory is consistent with curve given by experiment. 2) According to analysis of stresses and maximum load in soil due to slippage failure under a footing, the analytical results correspond well to the theoretical values given by Reissner. Thus two-dimensional elastic-plastic joint element presented herein is available for FEM analysis to express a discontinuous plane in the plastic phase.