硫酸盐、干湿循环和冻融循环耦合作用下混凝土单轴受压模拟

基于硫酸盐腐蚀混凝土单轴受压试验结果，通过对《混凝土结构设计规范》(GB50010—2010)中无腐蚀混凝土单轴压应力-应变关系中的混凝土损伤演化参数进行修正，建立了硫酸盐、干湿循环和冻融循环耦合作用下混凝土单轴受压本构模型。采用修正后的本构模型，以及ABAQUS软件自带的损伤塑性模型，考虑损伤因子的影响，较好地模拟了硫酸盐、干湿循环和冻融循环耦合作用下混凝土的单轴受压行为。有限元模拟结果表明：随着硫酸盐干湿循环次数和冻融循环次数的增大，混凝土最大受压损伤因子逐渐增大，损伤范围也逐渐扩大；最大主拉应力逐渐减小，中部压应力逐渐增大，等效塑性应变逐渐增大，混凝土破坏更严重；破坏均属于最大拉应变强度破坏。所提有限元模型可动态反映参数变化过程中混凝土的应力发展与损伤状态，可应用于硫酸盐、干湿循环和冻融循环耦合作用下混凝土单轴受压的模拟。

Uniaxial compression simulation of concrete under the coupled actions of sulfate, dry-wet cycles and freeze-thaw cycles

Based on the uniaxial compression test results of sulfate erosion concrete, a revised model was established by considering damage evolution parameter to uniaxial compression constitutive model of non-corrosion concrete in the Code for Design of Concrete Structures (GB50010-2010). Using the modified constitutive model and the plastic damage model of ABAQUS software, considering the influence of damage factors, the uniaxial compression behavior of concrete under the coupling effects of sulfate, drying-wetting cycle and freezing-thawing cycle was well simulated. Finite element simulation results show that as the increase of sulfate dry-wet cycles and of freeze-thaw cycles, the maximum damage factor of concrete and the damage range gradually increase. The maximum principal tensile stress continuously decreases, and compressive stress and equivalent plastic strain of the middle section increase gradually, and the failure of concrete becomes more serious. All samples fail under maximum tensile strain. The proposed finite element model can dynamically reflect the stress development and damage state of concrete with the change of parameter, and can be used to simulate the uniaxial compression behavior of concrete under the coupling effects of sulfate, dry-wet cycle and freeze-thaw cycle.