基于电测法的定向钻杆接头应力分布实验研究

Experimental study on stress distribution of directional drill pipe joint based on electrical measurement method

摘要:

煤矿定向钻杆在孔内受弯曲、扭转、振动及拉压等各种载荷作用，施工过程中经常出现钻杆断裂事故，应力集中是造成钻杆断裂的重要原因之一，研究钻杆接头螺纹的应力分布对预防钻杆断裂具有重要的意义。本文以电阻应变测量为基础，搭建定向钻杆全尺寸实物应力测试实验平台，对钻杆接头进行了拉伸应力实验，并将各个实验数据绘制成应力分布曲线。研究结果表明：钻杆公接头应力大于母接头应力，公接头和母接头的最大应力均在齿3的位置。通过应力分布趋势和各齿应力值的方式验证了仿真模型的正确性，提供了一种验证钻杆仿真模型正确性的方法。本研究的实验数据和应力分布曲线为钻杆有限元仿真提供了可靠的数据支撑。

关键词:定向钻杆;接头螺纹;应力测试;电阻应变;应力分布

Abstract:

The directional drill pipe in coal mine is subjected to bending， torsion， vibration， tension and other loads in the hole， and the fracture accident often occurs in the construction process. The main reason for the fracture of drill pipe is stress concentration. Based on the resistance strain measurement， this paper builds a full-size physical stress test platform for directional drill pipe， conducts tensile stress tests on drill pipe joints， and plots each experimental data into stress distribution curves. The results show that the stress of drill pipe pin is greater than that of drill pipe box， and the maximum stress of drill pipe pin and box is at the position of tooth 3. The correctness of the simulation model is verified by the stress distribution trend and the stress value of each tooth， and a method to verify the drill pipe simulation model is provided. The experimental data and stress distribution curve in this study provide reliable data support for the finite element simulation of drill pipe.

Key words:directional drill pipe;connection thread;stress test;resistance strain;stress distribution