混凝上倒T形盖梁疲劳过程模拟

引入一类双标量弹性疲劳损伤本构模型,对桥梁工程中常见的倒T形盖梁进行疲劳全过程分析。该模型采用受拉损伤内变量和受压损伤内变量来描述微观受拉和受压损伤机制对混凝土宏观力学性能劣化的影响,并根据有效应力空间的热力学原理确立了疲劳损伤的演化法则。通过将疲劳损伤本构模型与非线性有限元分析方法相结合,可以精细预测混凝土倒T形盖梁在疲劳荷载作用下的非线性行为,尤其是疲劳加载过程中裂缝的产生和扩展过程,为实际工程的疲劳分析和设计提供了依据。

Simulation of Fatigue Process of Concrete Inverted T-shaped Bent Cap

This paper introduces a bi-scalar elastic fatigue damage constitutive model to analyze the whole fatigue process of inverted T-shaped hent cap commonly in the bridge engineering.This model uses the internal variable of tensile damage and the internal variable of compression damage to describe the influence of microcosmic tension and compression damage mechanism on the deterioration of macro-mechanical properties of concrete.And based on the thermodynamic principle of effective stress space,the evolutional rule of fatigue damage is determined.The combination of the fatigue damage constitutive model and the nonlinear finite element analysis method can accurately predicate the nonlinear behavior of concrete inverted T-shaped bent cap under the fatigue loading effect,especially the formation and expansion process of crack in the fatigue loading process,which provide the basis for the fatigue analysis and design of the practical projects.