振动条件下螺纹面磨损对紧固件抗松能力影响

为改善振动条件下螺纹紧固件抵抗松动能力，在紧固件横向振动试验装置上，测试了微粒子喷丸未处理及处理镀锌紧固件的抗松动能力，使用扫描电镜观察测量了试验前、后螺纹面磨损形貌和尺寸，建立了考虑螺纹面磨损深度的紧固件刚度模型，利用该模型计算分析了磨损深度改变对预紧力的影响.结果表明:未喷丸紧固件预紧力耐久极限为2.8 kN，喷丸紧固件为2.0 kN，未喷丸紧固件抗松动能力低于喷丸紧固件，未喷丸紧固件螺纹面发生严重磨损，喷丸紧固件螺纹面磨损轻微；螺纹面磨损深度随着滑移距离的增加而增加，紧固件预紧力随着螺纹面磨损深度的增加先呈线性降低，随后降低速度逐渐加快.螺纹面磨损降低了紧固件抵抗松动的能力. 

Effect of Thread Wear on Anti-Loosening Ability of Threaded Fastener under Vibration

In order to improve the anti-loosening ability of threaded fasteners under vibration, the anti-loosening abilities of the electro-zinc-plated fastener (EZP) and the electro-zinc-plated fastener treated by fine particle peening (FPP-EZP) were evaluated using a fastener transverse vibration apparatus. The surface damage and worn dimensions of the thread before and after testing were observed and measured using scanning electron microscopy. Then, a fastener stiffness model considering thread wear depth was used for numerical simulation of the effect of the wear depth on the threaded fastener preload. The test results show that the preload endurance limits of the EZP and FPP-EZP are respectively 2.8 kN and 2.0 kN, this suggests that the anti-loosening ability of the EZP is lower than that of the FPP-EZP. The observation results show severe damage on the thread surface for EZP, but no distinct damage on the FPP-EZP threads. The numerical simulation shows that the thread wear depth increases with the increase of the relative sliding distance between threads. Furthermore, the preload initially decreases nearly linearly with the increase in thread depth, and then rapidly. The thread wear can reduce the anti-loosening ability of threaded fasteners.