竖向收进成束钢框筒结构受力性能分析

Mechanical Performance Analysis of Steel Bundled-tube Structure With Vertical Setback

为研究竖向收进方式对成束钢框筒结构性能指标的影响,探讨合理竖向收进方案,设计了沿竖向采用不同方式进行收进的系列算例模型.分析竖向收进部位裙梁及筒体柱的受力特点以及结构弹塑性层间位移角、损伤发生时间和能量耗散等.分析结果表明:等效风效应系数与基底剪力和倾覆力矩有相同的变化规律,可作为竖向收进方案的初选指标.竖向收进部位裙梁及筒体柱存在内力突然增大的现象,且具有明显的规律性.依据规范选波进行时程输入下,竖向均匀收进的算例模型筒体柱未出现塑性损伤,裙梁出现塑性损伤的时刻不同,但出现损伤时刻对应的结构总输入能较为接近.结果表明,成束钢框筒结构竖向收进起始位置应尽可能远离嵌固端,沿竖向宜分多次均匀收进.

In order to study the effect of different setback methods on performance indexes and the reasonable setback methods of bundled-tube s truc tu re,the calculation models with different setback were designed. Mechanical characteristics of columns and spandrel beams of uniform vertical setback models were analyzed. Elastic-plastic mechanical performance of the structures such as elastic-plastic story d r if t, time of damage happen and energy dissipation were researched. The results show that the changing rule of the equivalent wind effect coefficient is the same as the base shearing force and base anti-overturning moment,and is considered as reference indicator before initial setback method is decided. The internal force of columns and spandrel beams show regular abrupt in the vertical setback location. The time history analysis results of models with uniform vertical setback show that the columns do not occur plastic damage; the spandrel beams occur plastic damage at different time. The energy dissipation values,at the time of plastic damage occurance are approximated. The location of the initial setback should be as far as possible from the embedded en d. The reasonable setback method should be uniform.