改进敏感性指标法的杆系结构易损性分析

中国民航大学机场学院,天津 300300

空间结构; 杆系结构; 张弦桁架结构; 易损性分析; 敏感性指标; 抗连续倒塌

Vulnerability analysis of truss structure by an improved sensitivity index method
Liu Guoguang, Wu Zhiwei, Cheng Guoyong, and Chen Qi

Liu Guoguang, Wu Zhiwei, Cheng Guoyong, and Chen QiAirport College, Civil Aviation University of China, Tianjin 300300, P.R.China

spatial structure; truss structure; truss string structure; vulnerability analysis; sensitivity index; anti-progressive collapse

DOI: 10.3724/SP.J.1249.2014.05504

备注

为分析空间杆系结构的易损性,将日本钢结构协会建议的结构敏感性指标改进为体现移除杆件影响的单元敏感性指标. 利用有限元软件ALGOR,计算平面梯形桁架在5种杆件移除工况下剩余杆件的敏感性指标,检验利用单元敏感性指标法判断杆件移除顺序和识别结构倒塌模态的可行性. 将单元敏感性指标法用于张弦桁架结构易损性分析,研究双索张弦桁架结构在不同工况下剩余杆件的单元敏感性指标和结构竖向位移,阐述冗余索降低张弦桁架结构易损性的作用机理,通过有限元软件ANSYS,对构件敏感性指标进行数值计算,分析双索张弦桁架结构动力破坏模态

To analyze the vulnerability of truss structure, the structural sensitivity index suggested by the Japan Steel Construction Society was replaced by a member sensitivity index for reflecting the influences of removing bars. The member sensitivity index of a trapezoid truss in two dimensions was calculated by finite element software ALGOR under five working conditions of removing bars. The feasibility of member sensitivity index method was validated in determining the destroyed sequences of structural members and identifying the mode of structural collapse. Vulnerability analysis of truss structure was conducted by using the member sensitivity index method, structural member sensitivity indexes of remained bars. The structural vertical displacements under different working conditions of truss string structure with double cables were analyzed to illustrate the mechanism of vulnerability changes of truss string structure with the help of redundant cable. A dynamic progressive collapse characteristic analysis of truss string structure with double cables was carried out by the member sensitivity index method through finite element software ANSYS, by which the dynamic failure mode and progressive collapse characteristic of truss string structure with double cables were obtained. The results show that the member sensitivity index method is effective in analyzing vulnerability of spatial truss structure. The structural redundancy degree is increased by setting redundant cable and X-type supporting bars, which decrease member sensitivity index and structural vulnerability and enhance structural anti-progressive collapse ability under dynamic loads. The member sensitivity index method is verified to be feasible in analyzing vulnerability of truss structure.

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