[提要]  通过4根组合梁的纯扭试验，并参考另外已有的4根组合梁的试验结果，讨论了受扭组合梁的破坏形态。根据软化桁架模型理论，通过平衡、变形和协调条件，建立了组合梁抗扭特性分析的方程式，并给出了一种计算组合梁抗扭特性（抗扭强度、扭转角、开裂角、钢筋和混凝土应力、应变等）的简化算法，结果表明：理论值和试验值符合较好，可供组合梁的抗扭设计使用。
[关键词]  钢-混凝土组合梁 软化模型 抗扭特性 试验 分析

Experimental investigation of 4 steel-concrete composite beams was conducted to study the torisonal behaviors of steel-concrete composite beams. Based on the softened truss model theory, the equations were derived from equilibrium, compatibility and material's constitutive relations, and an efficient algorithm was proposed togive the ultimate torsional strength, the angle of twist, the stress and strain of reinforced steel and concrete and so on. The calculated conclusions were coincided well with experimental values.
Keywords: steel-concrete composite beam; the softened t,russ model; experimental research; theoretical analysis; torisonal behaviors