考虑孔周应力集中的摩擦型高强度螺栓抗滑移性能分析与设计方法研究

Research on the Anti-slip Performance and Design Method of Slip Critical High-Strength Bolted Connection Considering Stress Concentration

抗滑移性能是摩擦型高强度螺栓受剪连接的重要力学性能之一。为研究抗滑移性能的影响因素,设计并完成了单个高强度螺栓抗滑移性能试验和高强度螺栓群抗滑移性能试验,连接试件均为双面剪切且表面进行了抛丸处理。基于试验结果,建立了准确、可靠的有限元验证模型,据此对高强度螺栓受剪连接进行了参数分析,主要研究参数包括:螺栓预紧次序、连接板件厚度、垂直于内力方向的螺栓间距与边距以及顺内力方向的螺栓间距与边距。分析结果表明:连接板件最危险截面的塑性区分布对摩擦型高强度螺栓的抗滑移性能有着显著影响,设计时应考虑孔周应力集中现象对抗滑移承载力的折减;不同的截面受力情况对应的孔周应力集中系数存在明显差异。通过计算分析给出了螺栓抗滑移承载力折减系数建议值。相关研究成果可为摩擦型高强度螺栓受剪连接的设计提供改进思路。

Anti-slip performance is one of the important mechanical properties of shear connections with slip critical highstrength bolts.This research explores the influencing factors for anti-slip capacity.The slip resistance tests of single bolt and bolt group were designed and conducted.All the specimens were double shear connections and the surfaces of connecting plates were grit-blasted.Based on the test results,reliable and accurate finite element verification models were built.The parameter analysis was carried out by using numerical simulation.The studying parameters include bolts tightening sequence,plate thickness,bolt pitch and edge in both vertical direction and parallel direction of internal force.The results show that the plastic zone of the most dangerous section of the connecting plate has a significant effect on the anti-slip capacity of slip critical high-strength bolted connection,which should not be ignored in the calculation of shear capacity of slip critical bolted shear connection.The stress condition of the connecting plate section also affects the stress concentration around bolt holes.The recommended values for the reduction factor of bolt group shear capacity are given in this study.The relevant research results can provide an improvement for the design of shear connections with slip critical high-strength bolts.