基于Druck-Prager和MISO模型的混凝土三轴压缩行为有限元模拟

Finite Element Simulation of Concrete Behavior under Triaxial Compression Based on Druck-Prager and MISO Models

本文采用有限元分析软件ANSYS模拟了不同围压(0,25.5,51.2 MPa)条件下素混凝土圆柱试样压缩响应特征。首先,综合对比分析了Druck-Prager模型及多线性强化(MISO)模型的模拟效果。此外,进一步基于MISO模型分析了混凝土试件端部约束条件对模拟结果的影响。最终得到的主要结论包括:(1)单轴压缩条件下,有限元模拟结果与试验结果一致性较好,且Druck-Prager模型更适宜模拟混凝土体应变特征;(2)施加围压时,MISO模型所得抗压强度较保守,而Druck-Prager模型高估了混凝土抗压强度;(3)就MISO模型而言,端部摩擦约束对混凝土应力—应变曲线无显著影响,但会加剧混凝土体积膨胀(剪胀)。

In the present study, ANSYS, a finite element software, was employed to simulate compressive response of plain concrete cylinder specimens with different confining pressure(σL= 0 MPa, 25.5 MPa and 51.2 MPa). First, the simulation results based on DruckPrager and MISO models were comprehensively analyzed and co MPared. Furthermore, the effects of end restraint conditions of concrete specimens on performance of simulation were analyzed using MISO model. Ultimately, the main conclusions were figured out, including(1) under the condition of uniaxial compression, the results of finite element simulation were in accordance with the test results,and the Druck-Prager model was more suitable for simulating the volume strain of concrete;(2) with confining pressure, the compressive strength generated by MISO model was conservative, while Druck-Prager model overestimated the compressive strength of concrete;(3) in terms of the MISO model, friction constraint on ends had no significant effect on stress-strain curve of concrete, but it could promote volume expansion(shear dilation) of concrete.