基于黏结的型钢陶粒混凝土推出试验有限元模拟

Finite element simulation of push-out test of shape steelceramsite concrete with mutual bondability

考虑混凝土保护层厚度、配箍率、混凝土强度和型钢埋置长度等影响因素,对型钢陶粒混凝土推出试件进行有限元分析.分析中引入了型钢和陶粒混凝土界面黏结滑移本构关系,陶粒混凝土应力-应变关系采用包括上升段和下降段的分段式方程.有限元分析表明:试件中型钢正应力在同一横截面上是相同的,从加载端到自由端正应力变化梯度逐渐减小;等效约束系数小于0.01的试件发生劈裂破坏,大于等于0.01的发生推出破坏;有限元计算承载力和滑移与试验结果吻合较好,为型钢陶粒混凝土构件进行有限元分析提供参考.

Taking account of such factors as the concrete protective cover thickness,reinforcement ratio,concrete strength,and embedment length of shape steel,the finite element analysis of push-out specimen of shape steel-ceramsite concrete was carried out.Bond slip constitutive relation of shape steel-ceramsite concrete interface was introduced into the analysis and sectional equation was used to express the stressstrain relationship of the ceramsite concrete.Finite element analysis result indicates that the normal stress within shape steel in the specimen will be the same on the same cross-section and the stress gradient will gradually decrease from the loading end to the free end.Specimens with equivalent restraint coefficient less than 0.01 will be subjected to split failure and those specimens with the coefficient greater than or equal to 0.01 will be subjected to push-off failure.The bearing capacity and slip obtained with finite element computation will well be consistent with that of experiment and the foregoing finite element simulation will provide a reference for finite element analysis of shape steel-ceramsite concrete member.