摘要
为研究钢框架结构在倒塌过程中的动态受力性能，采用气缸作为激发装置模拟框架柱瞬间失效的情况，对平面钢框架结构开展了抗倒塌动力试验研究。试验结果表明：框架柱失效后，框架梁在很短的时间内由弯曲为主的受力状态转变为受拉为主的悬链线受力状态，期间主要经历了弹性受力、塑性铰出现和悬链线破坏等过程。基于对试验过程的数值模拟以及DoD规范中的公式，分析了结构抗倒塌时的动力效应放大系数取值方法。分析结果表明：采用静力弹性法对钢框架结构进行连续倒塌分析时，荷载动力效应放大系数可取2； 采用静力弹塑性分析时，需采用变化的荷载动力效应放大系数，其取值范围为1~2； DoD规范中的荷载动力效应放大系数公式可在一定程度上较为准确地反映钢结构的动力效应，但该公式无法反映结构进入强化阶段后荷载动力效应放大系数回升的情况。
In order to study the dynamic performance of steel frames during the collapse course, the dynamic experimental study of plane steel frame was carried out by adopting an air cylinder to simulate the scenario of a sudden column loss. Experiment results show that the situation of beams changes from initial mainly bending to finally mainly tension shortly after the column failure scenario, and the status of beams during collapse course undergoes the elastic status, plastic hinge formation, catenary formation and collapse in sequence. The dynamic amplification factor was discussed based on the numerical simulation and the DoD code. The results show that the load dynamic amplification factor can be 2 when using static elastic method to conduct the progressive collapse analysis; while the load dynamic amplification factor is variable when using static inelastic method, and the variation range is from 1 to 2. The load dynamic amplification factor formula in the DoD code can accurately reflect the dynamic effect of steel frames during collapse process to certain extent. But the formula cannot predict the rebound of load dynamic amplification factor while the structure enters hardening phase.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2016年第12期144-152,共9页
Journal of Building Structures
基金
国家自然科学基金项目(51608234)
江苏省自然科学基金项目(BK20160534)
关键词
钢框架结构
连续倒塌
动力试验
动力效应放大系数
steel frame structure
progressive collapse
dynamic experiment
dynamic amplification factor
