强震作用下框架结构的优化设计

An Optimal Design Method for Spacial Frame Structures under Severe Earthquake Loading

摘要:

针对第三水准"大震不倒"的抗震设防目标,提出一种在强震作用下框架结构的优化设计方法。依据"用相同的投资获最好的设计"的设计理念,以在强烈地震波的作用下框架结构最大的层间相对位移最小化作为优化目标,建立了同时满足体积约束的优化数学模型。采用动力有限元分析模型和高效的显式动力分析方法进行结构分析,获得最大的层间相对位移;采用改进的复形法求解优化数学模型;在显式动力分析软件ANSYS/LS-DYNA的基础上进行二次开发,实现了一个三维框架结构的抗震优化设计。数值结果表明该设计方法不一定获得抗震结构的最优设计,但能获得一系列抗震性能良好的设计,具有现实的工程意义。

Abstract:

To aim at the third level seismic fortification target： not collapse in severe earthquake conditions, an optimal design method for spacial frame structures under the severe earthquake loading is perfrothed. According to the design concept： get the best design with the same cost, the optimization mathematics model is established to minimize the maximal relative displacement between neighbor floors in building structure under severe earthquake loading, meanwhile, to satisfy the structural volume constraint. The model is solved with the improved complex method. At last, the 3-D seismic optimal design of a space frame is demonstrated by the second exploitation based on the explicit dynamic analysis soft ANSYS/LS - DYNA. The numerical value result indicates the design method not always achieve the optimum design of the seismic structures, but it can obtain a series of better seismic designs. So the optimal design method can be used in the practical engineering.