【摘要】 运用连续介质损伤力学的方法,分析轴压圆钢管混凝土(CFST)短柱在高应力水平下的非线性徐变效应.提出一种新的均匀约束条件下的混凝土塑性损伤本构模型(DPM-UC),以便于模拟高应力下的塑性和损伤演化;以DPM-UC为基础,提出一种新的考虑混凝土徐变三维特性的非线性徐变效应分析理论框架,建立相应的数值分析方法,并嵌入到有限元分析软件ABAQUS中.将不同应力水平下的徐变试验结果与分析结果进行对比,结果显示:当承受较大应力水平时,采用非线性与线性徐变理论的计算结果差异明显,采用非线性徐变理论的预测值与实测值更为接近,验证了所提方法的可靠性与合理性.更多还原

【Abstract】 The nonlinear creep effect of axial loaded short concrete-filled circular steel tubular columns under high stress levels was studied based on the continuum damage mechanics method. First, a new damaged plasticity model for uniform confined concrete(DPM-UC) was proposed, making it convenient to simulate the plasticity and damage evolution of concrete under high stress levels. Next, a new theoretical frame for nonlinear creep effect analysis considering 3 D characteristic was presented based on DPM-UC; a corresponding numerical analysis method was established and subsequently implemented into the finite element software ABAQUS. Finally, the analytical results were compared with the experimental results under different stress levels. Results show that the calculated results of nonlinear and linear creep theory differ significantly under high stress levels. The predictive value presented by the nonlinear creep theory is closer to the test results, thus the reliability and validity of the proposed method are verified.更多还原