钢筋混凝土复合受扭构件抗扭承载力统一方程的研究

Unity equation of torsional capacity for reinforced concrete members subjected to combined torsion

钢筋混凝土压弯剪复合受扭构件的受力性能非常复杂,其计算模型多样化,承载力计算结果具有很大的离散性.采用变角空间桁架理论对复合受扭构件进行受力分析,推导出了复合受扭构件抗扭承载力基本式.考虑构件形式、加载方式的影响,以混凝土轴心抗压强度为参数,建立了新的抗扭承载力统一方程.通过对不同强度、不同受力方式、不同加载制度共59根复合受扭试件的受扭承载力进行计算,并与美国ACI规范、我国现行混凝土设计规范进行对比,结果表明统一方程计算得到的承载力理论值与试验值吻合较好.

The mechanics performance of reinforced concrete members subjected to axial compression, bending, shear and torque is very complex. Several calculation models have been established to estimate the torsional capacity of combined torsion members. However, the calculation results of different models have a great variation. In this paper, variable-angle space truss model is adopted for analyzing the mechanics performance of reinforced concrete members subjected to combined torsion. With respect to various shapes of specimens, various load modes, and various strength of concrete, a unity equation about torsional capacity of combined torsional member is obtained. Based on the unity equation, the torsional capacity of 59 combined torsional specimens is calculated. In contrast with the equation of ACI and the code of China, the torsional capacity calculated by the unity equation agrees well with the results of experiment and is much better than the results of ACI code and China code.