用SAP5模拟分析井下钻具主轴强度

SIMULATION AND ANALYSIS ON STRENGTH OF PRINCIPAL AXIS FOR DOWNHOLE DRILLING TOOL WITH SAP5 PROGRAM

针对使用井下钻具时经常出现主轴在退刀槽附近突然断裂的问题 ,应用SAP5通用程序中的读入刚度单元模拟构造了接触单元 ,用有限元法对井下钻具主轴系统的结构强度进行了分析。计算结果表明 ,井下钻具被破坏的主要原因之一是不合理的上扣扭矩和钻压使主轴的退刀槽附近产生超过屈服极限的应力。在SAP5基础上用有限元模型对弹性接触问题进行了分析 。

An analogy contact element model was established by using the reading rigidity element in SAP5 programs. The strength of the principal axis system of a drilling tool was analyzed with the finite element method. The result illustrates that the large make up moment and drilling pressure can cause a very high stress exceeding the yield strength near the relief groove. The dangerous points may be coincided with the locations of the biggest stress. The fracture may occur suddenly next to the relief groove of the principal axis, which causes the destruction of drilling tool. It is proved that the analogy model is correct and effective.