高温下混凝土化学塑性-损伤耦合本构模拟及破坏分析

Coupled Chemo-Elastoplastic-Damage Constitutive Model of Concrete at High Temperature and Failure Analysis

提出了一个用于模拟高温下混凝土中化学-热-湿-力学耦合行为的化学塑性-损伤耦合本构模型。发展了用于积分率形式的耦合本构方程的三步算子分裂算法。导出了化学-热-湿-力学(CTHM)耦合本构模型的一致性切线模量矩阵,以保证对于全局耦合控制方程Newton迭代过程的二阶收敛率。算例数值结果显示了本文发展的化学塑性-损伤耦合本构模型在重现火灾和热辐射条件下的混凝土中化学-热-湿-力学耦合行为的有效性。

A coupled elastoplastic-damage constitutive model taking chemo-induced material elastoplastic-damage effects into account to simulate coupled chemo-thermo-hygro-mechanical behavior in concretes at high temperature, is proposed. A three-step operator split algorithm for the integration of the rate coupled constitutive equations is developed. Consistent tangent modulus matrices for coupled chemo-thermo-hygro-mechanical analysis are derived to preserve the quadratic rate of convergence of the Newton iterative procedure for fulfilling the global equations governing the coupled process. The numerical results illustrate the performance of the proposed constitutive model in reproducing coupled chemo-thermo-hygro-mechanical behavior in concretes in fire and thermal radiation.