摘要
张弦结构由刚性上弦和柔性下弦索通过撑杆连接而成,为半刚性结构,其整体失稳和破坏模式是张弦结构研究和设计的重点。提出两端受有水平力和竖向集中力的弹性支承连续拱模型来模拟张弦结构。根据该模型分析得出影响张弦结构弹性及弹塑性失稳机理及承载性能的关键参数,如拱的矢跨比、拱截面、索的垂跨比和索截面积。并根据这些参数,利用该模型对张弦结构进行参数化分析,得出避免张弦结构发生整体失稳和脆性破坏时上弦拱的矢跨比和截面面积以及索截面取值建议值,并进一步讨论了支座刚度对张弦结构极限承载力和弹塑性破坏的影响,为张弦结构抗连续倒塌设计提供技术支持和参考。
String truss structure is made up of rigid upper string and flexible lower string linked with staybars and the stability behavior and failure mechanism are the key points of research and design. Elastic bearing continuous arch whose two ends are applied horizontal force and vertical force is used to simulate string truss structure. According to the model, the key parameters, such as rise-span ratio, arch cross-section, sag-span ratio and cable area which influence the elastic and elasto-plastic instability behavior mechanism and failure modes of string truss structure were obtained. In order to avoid global instability and brittle failure, some suggestions for rise-span ratio, arch cross-section and cable area and so on were proposed through parametric analysis of the model. The effects of support stiffness on ultimate bearing capacity and elasto-plastic failure were discussed in detail. This investigation provides important technical supports and reference for progressive collapse design of string truss structure.
出处
《钢结构》
2014年第9期15-21,共7页
Steel Construction
关键词
张弦桁架
连续倒塌
整体稳定
矢跨比
极限承载力
string truss structure
progressive collapse
global stability
rise-span ratio
ultimate bearing capacity
