【摘要】 设置高温中和高温后不同的钢筋笼,用以区分高温中和高温后模型的异同,利用ABAQUS损伤塑性模型考虑混凝土损伤的积累,建立模拟高温中荷载对高温后钢筋混凝土梁受剪承载力影响的三维有限元分析模型。通过与试验结果的对比,验证了该模型具有较好的精度。采用该模型分析高温中不同荷载水平及作用位置对高温后钢筋混凝土梁受剪承载力的影响,结果表明:随着高温中荷载的增加,高温后钢筋混凝土梁受剪承载力降低;当高温中荷载小于其极限荷载的0.6倍时,受剪承载力降低较小,当高温中荷载大于其极限荷载0.6倍时,降低明显;对于高温中和高温后作用点相同的情况,剪跨比越小,受剪承载力下降越大;随着高温中荷载的增加,残余应变增大,但高温后刚度变化较小。更多还原

【Abstract】 Based on ABAQUS concrete damaged plasticity material model,a 3D finite element model was built for simulating the effect of loads during high temperature on the shear strength of RC beams after fire.Two reinforcement cages were set,one for during high temperature and the other for after.The model was validated by comparing the simulation results with the real fire tests.By means of this model,the factors,load magnitude and location during high temperature,were studied for their influences on the shear strength of RC beams after fire.The results show that as the increasing of loads during high temperature,the shear bearing capacity decreases.While the load is less than 60 percent of the ultimate bearing capacity,the shear bearing capacity decreases slowly,and it decreases rapidly when the load is more than 60%.The results also show while the load location is the same during and after fire,the smaller the shear span ratio is,the more the shear bearing capacity decreases;as the increasing of load during high temperature,the residual strain grows but the stiffness changes little.更多还原