基于双线形软化黏聚区模型的混凝土路面损伤开裂及承载力分析

Analysis of damage and bearing capacity of concrete pavement based on double linear softening cohesive zone model

为探究混凝土塑性软化对混凝土路面损伤及承载力的影响,基于双线形软化黏聚区模型,结合ABAQUS有限元软件,对三点加载混凝土小梁试验全过程进行模拟.比较了单、双线形软化黏聚区模型,计算了应力比为0.15、0.25、0.35的双线形软化黏聚区模型的模拟误差,分析了Winkler地基上混凝土路面板从加载到断裂全过程的承载力和截面应力分布变化.结果表明,采用应力比为0.25的双线形软化黏聚区模型,小梁的加载力裂纹张开位移曲线模拟结果与试验结果一致,小梁和混凝土板的极限承载力分别出现在底部混凝土发生损伤和开裂阶段,混凝土板极限承载力大小为板底拉应力达到混凝土抗拉强度时的1.75倍,为板底刚开始出现宏观裂缝时的1.09倍.Winkler地基上的混凝土板加载破坏表现出脆性断裂特征.

To study the effect of concrete plastic softening on the damage and bearing capacity of concrete pavement,the whole process of the three-point loading concrete beam test was simulated by the finite element soft ABAQUS based on the double linear softening cohesive zone model.The single and double linear softening cohesive zone models were compared,and the simulation deviations of the double linear softening cohesive zone model with different stress ratios of 0.15,0.25 and 0.35 were calculated.The bearing capacity and the cross-section stress distribution of the concrete pavement on the Winkler foundation from loading to fracture were analyzed.The results show that using the double linear softening cohesive zone model with the stress ratio of 0.25,the simulation results of the loading force-crack opening curve are in agreement with the test ones.The ultimate bearing capacities of the beam and the concrete slab occur when the concrete at the bottom is in the damage phase and the cracking phase,respectively.The ultimate bearing capacity of the concrete slab is 1.75 times of that when the concrete at the bottom reaches its tensile strength,and 1.09 times of that when the macro-crack appears at the bottom of slab.The loading failure of the concrete slab on the Winkler foundation shows brittle fracture characteristics.