三种混凝土本构模型在圆钢管再生混凝土轴压短柱有限元分析中的比较  

Comparison among Three Constitutive Models in Finite Element Analysis of Recycled Aggregate Concrete-Filled Circular Steel Tube Short Column under Axial Compression

作　　者：许福[1,2] 李科锋 曾楠[1] 邓旭辉 刘映良[1] 龙志林 

机构地区：[1]湘潭大学土木工程与力学学院,湖南湘潭411105 [2]工程结构动力学与可靠性分析湖南省普通高等学校重点实验室,湖南湘潭411105

出　　处：《湘潭大学自然科学学报》2017年第3期28-33,共6页Natural Science Journal of Xiangtan University

基　　金：国家自然科学基金项目(51401176;51471139);湖南省自然科学基金项目(14JJ3078)

摘　　要：为研究再生混凝土本构模型的特点及适用性,基于三种不同核心再生混凝土本构模型对钢管再生混凝土轴压短柱受力全过程进行非线性有限元分析,从极限承载力、轴压刚度、耗能因子等方面对数值模拟结果与93组试验数据进行对比分析.结果表明:在极限承载力方面,未考虑约束作用对峰值应力影响的本构模型计算结果偏安全;基于统一理论的本构模型计算结果对套箍系数较大的试件符合较好,而套箍系数较小时结果偏保守;考虑取代率、含钢率、钢材屈服强度对核心再生混凝土强度及弹性模量影响的约束再生混凝土本构模型,计算结果与试验结果符合程度较高.轴压刚度方面的分析表明,按照弹性叠加原理计算的构件轴压刚度相对于试验值偏低,而考虑再生混凝土取代率的组合轴压刚度计算方法及本构得到的计算刚度值与试验结果符合良好,另外两种本构的计算值偏于不安全.此外,三种本构模型计算的耗能因子均高于试验值,表现为模拟的荷载-位移下降段比试验曲线平缓.In order to invest igate the character ist ics and appl icabi l i ty of the recycled aggregate concrete （RAC） const i tut ive models, the whole process of load-displacement curves of recycled aggregate fi l led-con- crete circular steel tube short columns）RACFST） under axial compression were simulated by using nonl in-ear fini te element analysis（FEA） method based on three di f ferent const i tut ive models of core RAC. Compar -isons between the calculated results and 93 available exper imental tests by considerat ion ul t imate load-bear-ing capacity, axial compression st if fness and energy dissipat ion coef f icients were proposed as well. The re-sul t shows that load-bearing capacity predicted by adopt ing const i tut ive model regardless of the influence of const raint effect on peak stress is comparat ively conservat ive. Constitut ive models based on the unif ied theo-ry agree wi th the exper imental results for specimens wi th larger confinement index bet ter than those wi th smal ler ones. Whi le const i tut ive model of confined recycled concrete by considering the effects of replace-ment ratio, steel ratio, yield st rength of steel on the st rength and elastic modules of RAC agree wel l wi th experiments. Axial compression st if fness analysis indicates that, st if fness value calculate according to the e-last ic superposit ion principle is low relat ive to the exper imental data. Axial compression st if fness obtainswi th combinat ion calculat ion method and the const i tut ive model by considering the replacement rat io of RAC are in good agreement wi th the test resul ts, however, the calculated values of the other two const i tut ives show to be unsafe. In addi tion,the calculat ion of energy dissipat ion coef f icients based on the three kinds of const i tut ive model, are higher than the test results as the numer ical load-displacement curves decrease gently than the test curve f lat tens.

关 键 词：钢管再生混凝土 本构模型 有限元分析 承载力 轴压刚度 耗能因子 

分 类 号：TU398.9[建筑科学—结构工程]