中文摘要：

组合梁结构在实际工程中常处于弯扭复合受力状态,为探讨预应力单箱组合梁在复合弯扭作用下的扭转承载性能,引入了弯矩影响系数和预应力影响系数,提出了预应力单箱组合梁在弯扭作用下的开裂扭矩计算公式.并在大扭弯比条件下,基于空间桁架理论,推导了预应力单箱组合梁在弯扭作用下的极限扭矩计算公式.为了验证该理论的正确性,设计了4根模型梁试件进行弯扭加载试验.理论计算值与试验值的对比结果表明,由理论计算公式得出的结果与实际吻合良好,可为研究组合梁结构的复合弯扭问题提供一定的理论参考.

英文摘要：

The composite beam structures are always in a state of combined bending and torsion in practical engineering.In order to probe into the torsional bearing capacity of prestressed single-box composite beam under the action of combined bending and torsion,the formulas of cracking torque calculation on the single-box composite beam were proposed by introducing the influence coefficients of bending moment and prestressing force.Under the conditions of big bending-torsion ratio,the ultimate torque computational formulas of prestressed single-box composite beam were deduced under combined bending and torsion based on the space truss theory.For verifying the correctness of the suggested theories,four specimens of model were designed and studied.Through comparatively analyzing the experimental results and the theoretical results,it is shown that they are in good agreement,and it is a theoretical reference for researching the problems of combined bending and torsion of composite beam structures.