受拉螺纹联接的切齿力学分析及效果

Mechanics and Effect of Tooth Cutting in Threaded Connection under Tension Load

切齿是改善受拉螺纹联接载荷分布的有效措施,但目前对螺纹牙进行切齿主要依靠实际操作中的经验,对于切齿的理论研究并不深入,还没有明确的计算公式能描述切齿对螺纹受拉联接的影响。以切齿后的螺纹联接为研究对象,根据螺纹牙的几何结构,通过对每圈螺纹牙进行受力分析,研究螺纹牙齿面上的变形,推导出新的变形协调方程,建立了能够对每圈完整螺纹和切齿螺纹进行受力计算的新型力学模型。以P-110S管螺纹为计算研究实例,计算了不同的切齿参数对螺纹牙受力分布的影响,发现切齿降低了两端螺纹牙的受力,提高了中间螺纹牙的受力,使整体受力更为均匀。该理论模型及计算公式为研究切齿对螺纹受拉联接提供了一种新的计算方法。

Tooth modification cutting is an effective method for improving the load distribution in threaded connection,however,tooth modification cutting mainly depends on the experiences in practice and the analytical research is not sufficient by now.There are no specific equations that can describe the influences of tooth modification cutting on load distribution in threaded connection under tension load.According to the geometric parameters of thread teeth,the threaded connection with tooth modification cutting was taken as research object in this paper,and based on the mechanics analysis and the research on deformation in each thread tooth,a new deformation and covariant equation was developed.A new analytical model that can calculate the load distribution on complete teeth and cut teeth connection was obtained.Taking P-110S pipe threaded connection as a calculating example,the influences on load distribution with different cutting parameters was investigated.It can be found that tooth modification cutting can decrease the loads on both sides,enhance the loads on middle teeth and make the load distribution more uniform.The analytical model and equation proposed in this paper offer a new way to study the effects of tooth modification cutting on threaded connections.