钢筋混凝土矩形梁受双向弯扭作用的极限分析

Limit Analyses of Rectangular RC Beams under Torsion and Bending in Two Directions

提出了一个新的钢筋混凝土矩形构件在双向弯矩和扭矩共同作用下的极限分析方法。首先根据构件所受到的外力确定构件破坏时的破坏翘曲面,其次通过分析得到破坏翘曲面上的应力分布,最后利用平衡方程得到双向弯扭作用下的强度计算公式。根据极限分析原理,提出的方法为一个偏于安全的下限解,得到的结果应比实际破坏荷载偏小。该方法计算简单,与现有试验结果符合较好,可进一步推广到更复杂的受力情况。

A new limit analysis method for rectangular reinforced concrete （RC） beams subjected to combined torsion and bending in two directions was proposed. Based on the warped failure surface determined by external loads, with an assumed reasonable stress distribution, new strength equations were derived from the equilibrium conditions, which should be a lower bound in limit analyses. The new equation is simple and conceptually clear. Comparing with existing test results, it is shown that the new method is in good agreement with existing test resuhs. It may also be used in more complex external loadings cases.