摘要
在动力荷载作用下单层网壳结构杆件受力和结构承载力处于动态变化中,因此要得到准确的结构实时动力响应,必须建立能够模拟杆件实时受力性能的杆件计算模型。根据单层网壳结构杆件的受力特点,总结出受压杆件的两种失稳类型。引入国际标准化组织推荐的空间受力圆钢管失稳判别准则,采用3节点塑性铰单元和Marshall模型分别模拟受压杆件失稳前后的受力性能,建立了杆件计算模型,该计算模型能够模拟杆件在动力荷载作用下经历失稳、拉直与塑性铰形成直至消失的过程。计算结果表明:采用有限元软件通用梁单元模拟单层网壳结构杆件将高估结构在地震作用下的承载力;应用本文的杆件计算模型,可以准确得到单层网壳结构在地震作用下的杆件受力变化过程及由此造成的结构承载力的动态变化过程,实现了对单层网壳结构动力响应全过程的精细化模拟。
Under dynamic excitation,the loads imposed on the members of the single-layer latticed shells change continuously,resulting in the change of load carrying capacity of the structure.The numerical model for the simulation of the real time mechanical behavior of the member is necessary,to obtain the accurate real time dynamic responses of structures.Based on the mechanical characteristics of the single-layer latticed shell member,two buckling types for compression members were summarized.The buckling criterion of the International Standard Organization was introduced.The three-node plastic hinge beam model and the Marshall model were used respectively to simulate the pre-buckling and post-buckling mechanical behavior of the member.The member calculation model was established accordingly.By this model the reversed processes such as buckling-straightening of the member and the forming-disappearing of the plastic hinge can be simulated.Calculational results indicate that the structural load carrying capacity is overestimated if the members of the single-layer latticed shells are modeled by the general beam element of the finite element program.Dynamic responses were calculated based on the member calculation model presented in this paper.The results indicate that the change of member mechanical behavior and the consequent change of structural bearing capacity of single-layer latticed shell can be calculated accurately.The refined simulation of the full-range dynamic response of the single-layer latticed shell subjected to dynamic excitation is then realized.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2011年第5期85-91,共7页
Journal of Building Structures
基金
国家自然科学基金重大研究计划重点支持项目(90715034)
国家自然科学基金面上项目(50978181)
教育部新世纪优秀人才支持计划(NCET-06-0229)
天津市应用基础及前沿技术研究计划(09JCZDJC25200)
关键词
单层网壳
杆件失稳
计算模型
有限元分析
动力响应
single-layer latticed shell
member buckling
calculation model
finite element analysis
dynamic response
