摘要
为使结构易损性分析更符合实际破坏情况,考虑了材料的塑性性能,提出了桁架结构杆件塑性重要性系数的计算方法,进而实现桁架的优化设计.首先假设杆件为弹塑性材质,以刚度损失定义杆件的塑性状态及破坏模式,采用附加荷载来考虑塑性阶段的结构承载力;其次建立桁架结构刚度矩阵与变形刚度矩阵之间的关系,寻求杆件位移与变形的内在联系,由此推导杆件塑性重要性系数;最后,通过预先假设桁架受力最不利情况和破坏模式,基于前述塑性重要性系数计算,实现桁架杆件的优化.通过一榀平面桁架算例说明了考虑材料塑性性能时得到的重要性系数值与仅考虑弹性性能有所区别,桁架失效模式更合理.同时桁架结构优化后,可以充分利用各杆件的抗力.
To present structural vulnerability analysis close to real-world failure situations,a practical method considering material plastic properties was developed for calculating the component importance coefficients of a truss structure.The structural design was then further optimized. Firstly elastic-plastic material properties were assigned for all the structural components,whose plastic situations and failure patterns were defined by their stiffness loss.During the plastic period,the truss bearing capacity was considered by means of additional loads.Secondly,the relationship between structural stiffness and deformation matrices was established to find the inherent connection between components'displacements and deformations.After that,the plastic importance coefficient of each component could be deduced.Lastly,through predefining the worst load scenario and the failure pattern,the component design of the truss structure was optimized using the developed method.The analysis results demonstrate that the material plastic properties affect the evaluation of importance coefficients.The truss failure patterns become more rational.Meanwhile,after design optimization the components better utilize their resistance under external loads.
作者
方圣恩
张立森
FANG Sheng'en;ZHANG Lisen(School of Civil Engineering,Fuzhou University,Fuzhou 350116,China;National and Local United Research Center for Seismic and Disaster Informatization of CiviI Engineering,Fuzhou University,Fuzhou 350116,China)
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2018年第6期1281-1293,共13页
Journal of Basic Science and Engineering
基金
国家自然科学基金面上项目(51578158)
福州大学“旗山学者”奖励支持计划(GXRC-1688)
关键词
桁架结构
易损性分析
塑性破坏模式
塑性重要性系数
结构优化
truss structure
vulnerability analysis
plastic failure patterns
plastic importance coefficients
structural optimization
