半刚性连接石油井架的动态特性研究

Study on the Dynamic Response of Oil Derrick Structure with Semi-rigid Joints

为研究焊接节点的半刚性对钻机井架结构动态特性的影响,通过组件法计算了节点初始刚度和极限弯矩的理论值.采用双向变刚度零长度螺旋弹簧模拟节点的半刚性,建立了半刚接井架的有限元模型并进行了自振特性和谐响应分析.与刚接井架对比表明:节点的半刚性对井架结构固有频率影响显著,随着连接节点刚度的减弱,井架低阶固有频率值呈现不断减小的趋势,而井架侧移和前倾趋势则显著增加,给井架安全带来一定隐患.

In order to study the influence of semi-rigid joints on the dynamic characteristics of the mine derrick structure, the theoretical calculation formula of the stiffness and ultimate moment of the welded joint between the derrick and the joints are obtained by the component algorithm. The zero-length spiral spring with dual direction and variable stiffness is applied to simulate the semi-rigid joints, the finite element model of semi-rigid derrick is established, the harmonic response analysis and the natural vibration characteristics are carried out. By comparing with the rigid connection, semi-rigid joints have a significant effect on the natural frequency of the derrick structure. With the decrease of the stiffness of the joints, the natural frequency of the derrick structure decreases and the derrick lateral displacement and the forward tendency significantly increase, which bring some safe trouble to the derrick.