螺距和孔隙对螺栓连接自松弛的影响

为了研究螺距和孔隙对螺栓连接自松弛的影响,建立了带螺纹的三维螺栓连接有限元模型,使用Newmark算法进行了螺栓连接横向振动瞬态求解,分析了不同螺距和孔隙对螺栓连接横向振动自松弛的影响。研究结果表明:在横向循环载荷作用下,粗牙螺纹的螺栓连接相比细牙螺纹的预紧力下降速度要慢、螺纹啮合面和承压面的滑移要剧烈,因此细牙螺纹较粗牙螺纹不容易发生自松弛;孔隙越大螺栓连接预紧力下降速度越快、螺纹啮合面和承压面的滑移越剧烈,因此，孔隙越大越容易发生自松弛。

The Effect of Thread Pitch and Clearance on Self-loosening of Bolted Joints

Aimed at studying the effect of thread pitch and clearance on self-loosening of bolted joints, this paper builds up a three dimensional FEA model of bolted joints in which thread is taken into consideration, and the simulation of self-loosening of bolted joints under transverse vibration is conducted based on the Newmark algorithm. Then the effect of thread pitch and different clearance on self-loosening of bolted joints is analyzed. The results show that the preload of bolted joints with coarse thread pitch falls faster than the preload of bolted joints with fine thread pitch, and the slippage of bolted joints with coarse pitch is acuter than the slippage of bolted joints with fine pitch, thus the self-loosening of bolted joints with fine thread pitch is more difficult to happen; and the larger clearance of bolted joints, the more rapidly the preload falls and the acuter the slippage is. The self-loosening of bolted joints with larger clearance is easier to happen.