输气管道法兰螺栓紧固力衰减及其影响机制实验研究

Experimental Study on Preload Attenuation and Its Influence Mechanism in Flange Bolted Joints of Gas Pipeline

承受横向载荷的法兰螺栓紧固力衰减行为是导致输气管道密封失效的重要因素。通过设计单螺栓切向试样,实验研究横向振动幅值和频率对紧固力衰减的影响规律,采用MATLAB软件对实验数据进行拟合,提出用多项式表征螺栓连接紧固力衰减行为的数学模型。此外,实验结果表明螺栓连接紧固力的衰减过程可划分为快速和缓慢下降两个阶段,且振动载荷幅值对紧固力衰减影响较大,为螺栓连接松动机理及有效防松措施的提出提供了重要依据。

The attenuation behavior of preload in flange bolted joints subjected to transverse load is an important factor leading to sealing failure of gas pipeline.The influence of transverse vibration amplitude and frequency on the attenuation of tightening force was experimentally studied by designing a single bolt tangential specimen.The experimental data were fitted by MATLAB software,and a polynomial mathematical model was proposed to characterize the attenuation behavior of tightening force.In addition,the experimental results show that the attenuation process of bolt preload can be divided into two stages:rapid and slow decline,and the amplitude of vibration load has great influence on the attenuation of tightening force,which provides an important basis for the loose mechanism of bolted joints and effective anti-loosening measures.