深孔绳索取心钻杆抗拉脱能力有限元分析

Finite element method of resistance to pull-off for deep hole wire-line drill rod

针对深孔施工过程中钻杆接头螺纹拉脱、杆体拉断等问题,以非线性有限元理论为基础,运用大型通用有限元软件对不同扣型不同参数下绳索取心钻杆螺纹副在拉伸及拉扭条件下的抗拉脱能力进行了分析计算。研究结果表明,螺纹副锥度相同时,负角度梯形扣的抗拉脱能力最强,不对称梯形扣的抗拉脱能力次之;同一扣型条件下,锥角变小时,螺纹副拉脱力呈现出先降后升的变化趋势;对于负角度梯形扣,随着负角度的不断增大,其抗拉脱能力有所增加;相对于拉伸,拉扭条件下螺纹副受力较为复杂,其抗拉脱能力略有降低。

Aiming at the problems such as pall-off of joint thread and breaking of rod,based on non-linear finite element method,the analysis and calculation of resistance to pull-off for deep hole wire-line drill rod with several types of thread under different working conditions was carried out by using finite element software.Results showed that barb trapezoidal thread performed best and buttress thread was better under the same thread taper;with smaller thread taper,the pull-off force showed upward trend after the fist under the same type of thread;with larger negative angle,its resistance to thread pull-off was increased;compared with tension,pull-off force decreased slightly under the tension and torsion.