A thermodynamically consistent nonlocal damage model for concrete materials with unilateral effects
A thermodynamically consistent nonlocal damage model for concrete materials with unilateral effects
复制标题
具有单向效应的混凝土材料的热力学一致非局部损伤模型
DOI：
10.1016/j.cma.2015.09.010
复制
发表时间：
2015-12-01
影响因子：
7.2
通讯作者：
Fu, Ting-Ting
中科院分区：
文献类型：
--
作者：
He, Wei;Wu, Yu-Fei;Fu, Ting-Ting
针对混凝土材料损伤建模中存在的问题，提出了混凝土材料的自洽本构模型。采用两个分离的等效应变和相应的新损伤演化规律，增强了对混凝土非对称性行为的描述能力，这是经典应变驱动模型无法同时再现的拉压强度差异和峰后行为。与单边效应有关的裂纹张开-闭合准则描述为，使用应变张量的迹而不是特定二阶张量的谱分解，这导致闭合载荷循环时的不连续应力-应变响应或虚假能量耗散。一个积分型非局部正则化被纳入解决问题的应变软化引起的网格非客观性涉及网格尺寸和网格偏差的依赖性。应变驱动的形式和显式积分的本构方程提高了数值算法的鲁棒性。使用现有的基准测试结果的相关研究，以证明该模型的性能。(C)2015 Elsevier B. V.版权所有。
This paper proposes a thermodynamically consistent constitutive model for concrete materials to solve several problems encountered in the existing damage modeling. Two separated equivalent strains and the corresponding new damage evolution laws are used to enhance the representation of asymmetrical behaviors of concrete, of which the different strengths and post-peak behaviors between tension and compression cannot simultaneously be reproduced by the classical strain-driven models. The crack opening-closure criterion related to the unilateral effect is described, using the trace of the strain tensor rather than the spectral decomposition of a specific second-order tensor, which leads to either a discontinuous stress-strain response or spurious energy dissipation upon closed load cycles. An integral-type nonlocal regularization is incorporated to solve the problem of strain-softening induced mesh non-objectivity involving mesh-size and mesh-bias dependencies. The strain-driven formalism and the explicit integration of constitutive equations improve the robustness of the numerical algorithm. Correlative studies using available benchmark test results are presented to demonstrate the performance of the model. (C) 2015 Elsevier B.V. All rights reserved.