装配式冷弯薄壁型钢结构中4种连接的抗剪性能试验研究

Experimental Study on Shear Behavior of Four Connections in Fabricated Cold-formed Steel Structures

为了解决自攻螺钉、拉铆钉、无铆、锁铆连接技术在装配式冷弯薄壁型钢结构中应用可行性的问题,对不同板厚组合下4种连接的抗剪性能进行了试验研究:总结了4种连接的破坏模式及荷载-变形曲线;考察了板厚比对不同连接力学性能及破坏模式的影响;通过力学性能与施工可行性的对比分析,综合评估了4种连接技术应用于装配式冷弯型钢结构中的可行性.研究结果表明:板厚比对无铆连接的破坏模式影响较小,而对自攻螺钉、拉铆钉、锁铆连接的影响较大;自攻螺钉和拉铆钉连接具有较高的承载力和变形能力,且施工灵活性较高,但自动化程度很低,主要适用于现场建造的冷弯薄壁型钢结构;无铆连接的承载力、变形能力低,且施工灵活性差,不宜用于冷弯薄壁型钢结构中的受力构件;锁铆连接具有较好的力学性能,且工序简单,自动化程度、连接效率高,成形质量好,主要适用于装配式冷弯薄壁型钢结构.基于前述研究,提出了与规范相统一的锁铆连接抗剪承载力计算公式,其计算精度高、离散性小.

To evaluate the feasibility of self-drilling screw,blind rivet, clinchin g ,and self-piercing rivet （SPR） connections in fabricated cold-formed steel structures, an experimental study was conducted on shear behavior of four connections under different steel sheet thickness. Failure modes and load- deformation curves of four connections were summarized. The effects of thickness ratio on mechanical behavior and failure modes were observed. The feasibility of four connections in fabricated cold-formed steel structure was comprehensively evaluated by comparison analysis of mechanical behavior and construction feasibility. The results show that thickness ratio has small influence on failure mode of clinching but has great effect on self-drilling screw,blind rivet ,and SPR. Both self-drilling screw and blind rivet have higher shear strength, deformability,and construction feasibility,but automatic level is lower,which can use on-site construction of cold-formed steel structures. Clinching should not apply in cold-formed steel structures because of lower strength, deformability, and construction flexibility. SPR has better mechanical property and high efficiency, which primarily applies to fabricated cold.formed steel structures. Based on aforementioned studies, a design method with high accuracy and small discreteness of SPR connections is proposed.