长宽比对矩形网架受力性能影响研究

Study on the effect of length-width ratio on the mechanical behavior of rectangular space truss

通过对大中跨度的矩形四角锥网架的多个计算案例分析对比,发现矩形网架结构在长宽比大于1. 5时,表现出完全的单向板受力特性;长宽比在1. 2~1. 5之间时,单向板性能随长宽比增加而变得显著;长宽比小于1. 2时,基本表现为双向板受力特性。当网架表现出较强单向板受力特性时,会造成单向杆件截面较大,给设计带来一些问题。结合实际工程项目,给出了改善网架双向受力性能的方法。

By comparing several calculation cases of rectangular quadrangular pyramid space truss with large and medium span,it is found that the rectangular space truss structure exhibits complete unidirectional slab force characteristics when the aspect ratio is greater than 1. 5;when the aspect ratio is between 1. 2 and 1. 5,the performance of unidirectional slab becomes remarkable with the increase of aspect ratio;when the aspect ratio is less than 1. 2,it basically shows bi-directional slab force characteristics. When the space truss exhibits strong unidirectional plate force characteristics,it will cause large cross-section of unidirectional members,which will bring some problems to the design. Combining with the actual engineering project,the method to improve the two-way force performance of grid structure is given.