混凝土宏观本构模型研究进展

State-of-the-art of macroscopic constitutive models of concrete

近年来,随着结构工程的快速发展,对结构在罕遇地震和风载作用下的精准数值模拟与性能化设计提出了更高需求。结构工程中的混凝土属于准脆性材料,试验表明混凝土具有显著的受压软化、受拉软化、剪切软化和捏拢效应等特性。针对上述特性,概述了结构工程数值模拟中常用的6种混凝土数值模型,包括非线性弹性模型、脆性裂缝模型、弹塑性裂缝模型、损伤模型、微平面模型和基于解耦假定的全量型本构模型,并基于文献调研评价了已有模型的不足。多面塑性模型对于混凝土构件单调加载取得了较好的预测精度;塑性损伤模型较难模拟裂面剪切行为;基于解耦假定的全量型模型可近似考虑混凝土的受压软化、受拉软化、捏拢效应、主拉应变导致的强度折减效应和剪切软化等问题。此外,概述了宏观本构模型有待进一步研究的问题。可为结构工程中混凝土本构模型的选用和参数标定提供相关依据。

Recently,with the rapid development of structural engineering,the high-fidelity nonlinear numerical simulation and performance-based design of engineering structures under rare earthquake and wind load are strongly required.The concrete material in structural engineering is quasi-brittle material,and experimental studies have shown that the concrete has notable major characteristics such as compression softening,tension softening,shear softening and pinching effect.Six kinds of concrete constitutive models in structural engineering,including nonlinear elastic model,brittle cracking model,elasto-plastic crack model,damage model,microplane model and total value model based on decoupling assumption were reviewed.The weakness of existing models was evaluated based on the literature review.Multi-surface plasticity models achieve relatively good prediction accuracy for uniaxial loading of concrete members.Plasticity damage models may be difficult to simulate the shear force transfer across cracked surfaces.The total value model based on decoupling assumption can approximately considering the compression softening,tension softening,pinching effect,strength degradation due to principal tensile strain,and shear softening.In addition,prospective problems of macroscopic constitutive models that need to be investigated were illustrated.This paper provides reference for the selection of concrete constitutive models and parameter calibration in structural engineering.