ABAQUS在超高层结构动力弹塑性分析的应用研究

Application study on ABAQUS in dynamic elasto-plastic analysis of super high-rise buildings

为提高ABAQUS在超高层建筑动力弹塑性模拟方面的适用性问题,提高ABAQUS的建模、计算效率及应用的灵活性,基于塑性损伤力学理论独立开发了适用于混凝土梁柱纤维模型的混凝土一维拉压循环加载材料模型。利用钢筋混凝土板的塑性绞线理论解决了异形钢筋混凝土板的导荷问题,同时利用铺网格法实现了对楼板及墙单元的精细剖分。通过用户子程序开发,实现了在ABAQUS显式算法中应用振型阻尼,避免了在显式算法中采用瑞雷阻尼带来的模拟精度难以保证的问题。根据ABAQUS的能力和特点,完善了隐式算法和显式算法对超高层结构的模拟路径。通过采取适当措施在两种算法中均实现了计算精度与计算速度的统一。对比研究算例显示,隐式积分算法与振型叠加法结果较为接近。显式积分算法对阻尼比的取值较为敏感,同样的阻尼比取值达到的阻尼效果比隐式积分算法大。

The main research interest is to improve the feasibility of ABAQUS in modeling the dynamic elasto-plastic behaviors of super high-rise buildings, and to improve the modeling and computational efficiency and the application flexibility of ABAQUS. A material model based on plastic and fracture mechanics was proposed for concrete under uniaxial tensile-compression cyclic loading. Upon plastic hinge theory of reinforced concrete slab, an innovative meshing procedure including load transferring mechanism was recommended for irregular shaped slabs. Meanwhile, the laying grid meshing method was also introduced for elastic slabs and walls for an explicit meshing purpose. The orthogonal damping matrix was formed for the structural system and the corresponding damping load of each story was applied through user subroutine. According to the capabilities and characteristics of ABAQUS, the simulation path of implicit and explicit algorithms for super high-rise structures was improved. The unification of calculation accuracy and calculation speed was achieved in both methods by taking appropriate measures. The comparison study shows that the implicit method achieves closer result to mode supposition method than the explicit method taking the same damping ratio. The explicit integration algorithm is sensitive to the value of damping, and the same damping ratio value results a greater damping effect in explicit method than in implicit method.