钢筋混凝土弹塑性损伤本构模型  

Elastoplastic Model with Damage for Reinforced Concrete

作　　者：展婷变[1] 宁建国[2] 王志华[3] 任会兰[2] 

机构地区：[1]中北大学机电工程学院,山西太原030051 [2]北京理工大学爆炸科学与技术国家重点实验室,北京100081 [3]太原理工大学材料强度和结构冲击山西重点实验室,山西太原030024

出　　处：《中北大学学报（自然科学版）》2017年第3期380-390,共11页Journal of North University of China(Natural Science Edition)

基　　金：国家自然科学基金资助项目(11390362);山西省青年科技研究基金资助项目(201601D202005);中北大学2016年校科研基金资助项目

摘　　要：钢筋混凝土在加载过程中内部应力应变是不均匀的,因而很难通过试验直接得出本构关系.为了避开非均匀性对研究本构关系带来的困难,通过钢筋混凝土的载荷变形关系,提出了钢筋混凝土弹塑性损伤本构模型.该模型假设钢筋混凝土的力学行为由两部分组成,一是由微裂纹形成的损伤行为,它具有零屈服强度的刚性完全塑性本构关系;二是基体行为,服从不包括软化的弹塑性本构关系.在加载过程中,变形的增加使前一种行为转化为后一种行为.模型包括4个阶段:线弹性阶段、混凝土为主体的弹塑性阶段、钢筋为主体的弹塑性阶段和应变软化阶段.模型反映了损伤引起了钢筋混凝土应变软化、剪切刚度降低和诱致各向异性.采用Willam-Wanke塑性本构描述混凝土的非线性行为,其参数标定通过Hsu的软化桁架理论以及Vecchio&Collins的修正压应力理论进行,考虑了钢筋混凝土中钢筋与混凝土之间的相互作用.运用此模型分析钢筋混凝土梁的载荷-挠度关系,并与实验结果相比较,验证了模型的正确性.During the loading process, stress and strain are inhomogeneous in the reinforced concrete, so it is difficult to determine the constitutive relation from the tests.In order to ignore the difficulties in identifying the influence of such nonhomogeneities, an elastoplastic model with damage for reinforced concrete is proposed by the observed load-deformation relations in this paper.It is assumed that behaviour of reinforced concrete element is decomposed in two parts.In the first part, which refers to the damaged part, the behaviour is depicted as rigid, perfectly plastic with zero yield strength.The second part, representing topical behaviour, is non-softening and obeys an elastoplastic constitutive law.During the loading process, topical behaviour is “transformed＆quot; to damaged one.The model is divided into four intervals： the elastic stage, the based elastoplastic stage on concrete, the based elastoplastic stage on reinforcement and the strain softening stage.The damage variable is responsible for the softening in strength, for the degradation of the elastic shear modulus, and for induced anisotropy.The parameters of rebar and concrete are calibrated by the softened truss mod proposed by Abdeldjelil ·Hsu and the modified compression field theory proposed by Vecchio · Collins, considering the interaction between the concrete and reinforcement.The model is applied to analyze the load-deflection relationships of RC beams and shows very good agreement with the experimental results.

关 键 词：钢筋混凝土 塑性 本构 损伤 强度 

分 类 号：O347[理学—固体力学]