曲线钢-混凝土结合梁桥的混凝土收缩徐变效应计算

Calculation for Effect of Concrete Shrinkage and Creep on the Steel-Concrete Composite Beam Bridge

将混凝土的应变分解为瞬时应变、徐变和收缩应变三部分之和,基于CEB-FIP模型提出了模拟收缩徐变的简明本构模型.根据本构模型给出了收缩徐变产生的单元等效结点力增量计算式,并结合迭代法逐步计算原理给出了计算收缩徐变的有限元公式.最后,应用收缩徐变模型和对应的有限元计算理论编制程序计算了曲线钢-混凝土结合梁桥的收缩徐变效应,结果表明收缩徐变对曲线钢-混凝土结合梁桥的内力和变形均有很大的影响.

The strain of concrete was decomposed into instantaneous strain, creep strain and shrinkage strain. A simple constitutive model for modeling shrinkage and creep effect on concrete was proposed based on CEt3-FIP model. The proposed model was applied to derive the element equivalent nodal force increment, and the finite element formulation for shrinkage and creep calcula- tion was presented based on the step-by-step iterative method. Finally, the shrinkage and creep mod- el and its corresponding finite element formulation were applied to calculate the effect of shrinkage and creep on the curved steel-concrete composite beam bridge. The result of calculation shows that the shrinkage and creep of concrete have a great influence on internal force and deformation in the curved steel-concrete composite beam bridge.