钢筋混凝土薄膜元理论

Theory of Reinforced Concrete Membrane Elements

承受平面内剪应力和正应力的钢筋混凝土和预应力混凝土薄膜元的软化桁架模型已经发展起来。这种模型满足二维应力平衡条件、莫尔应变协调条件和混凝土的双轴软化本构关系。它不仅能预估薄膜元的强度，而且能表达荷载－变形关系的全过程。本文叙述了两种软化桁架模型，它们的区别是对混凝土压杆角度的假定不同。首先概述已完整建立起来的转角软化桁架模型，然后给出定角软化桁架模型的新发展。

A softened-truss model has been developed for reinforced and prestressed concrete membrane elements subjected to in-plane shear and nomal stresses. This model satisfies the twodimensional stress equilibrium, Mohr's circular strain compatibility and the softened biaxial constitutive laws of concrete.It can predict not only the strength, but also the load deformation history of a membrane element. This paper describes two types of softened-truss model,depending on the assumption for the angle of concrete strutS.The rotating-angle softenedtruss model,which is well established, is first summarized.Then the new development of the fixed-angle softened-truss model is given.