基于时变力学分析的某高层框架-核心筒结构施工模拟

Construction simulation of a high frame-tube structure based on time-varying mechanics

基于时变力学理论,讨论了施工过程模拟的力学原理和慢速时变结构基于时间冻结法和有限元生死单元技术的求解方法。采用观测层以下各层不施加重力加速度的方法模拟了施工过程中的找平措施,使得观测层的变形仅由其上各层的重力荷载和施工荷载引起,而不受其下各层累积变形的影响;同时各层的质量和刚度仍然计入总体结构的质量和刚度矩阵,满足了结构整体分析的要求。用三种不同的施工模拟方法对某典型的高层框架-核心筒结构进行了对比分析。结果表明,由于近似模拟施工方法考虑了施工找平措施的影响,计算结果比一次加载法更加接近施工过程的实际情况;同时,近似模拟施工方法的质量矩阵和刚度矩阵在整个模拟过程中只需组集一次,建模过程和计算所需工作量均远小于精确模拟施工方法。

The mechanics principle and the solution method of construction simulation based on the time freezing method and birth-and-death element technique are discussed according to the time-varying mechanics theory. The construction leveling measures is simulated by not exerting gravity in the layers under the observed layer, which made the deformation of the observed layer not accumulate by the lower layers, but resulted in the gravity load and construction loads of the upper layers. Meanwhile, the mass and stiffness are counted in the mass matrix and stiffness matrix of the overall structure, which meet the requirements of the response analysis. The construction simulation of a typical high frame-tube structure is performed with 3 different kinds of construction simulation methods. The result shows that the solution of the approximate construction simulation method is more accurate than the one-time loading method for considering the construction leveling measures. Moreover, the computational cost is far less than the accurate construction simulation method because its mass and stiffness matrixes are both assembled one -off.