中国机械工程 ›› 2026, Vol. 37 ›› Issue (9): 2314-2325.DOI: 10.3969/j.issn.1004-132X.2026.09.024

• 先进材料加工工程 • 上一篇    

几何缺陷结构对钻具螺纹强度与疲劳寿命影响分析

芦烨(), 丁宇奇(), 雷紫煌, 吕奇霖, 李智超, 李康健   

  1. 东北石油大学机械科学与工程学院, 大庆, 163318
  • 收稿日期:2025-08-18 出版日期:2026-09-25 发布日期:2026-10-21
  • 通讯作者: 丁宇奇
  • 作者简介:芦烨,女,1985年生,讲师。研究方向为杆管柱连接螺纹强度平度与优化分析。E-mail: luye_nepu@163.com
    丁宇奇*(通信作者),男,1982年生,教授、博士研究生导师。研究方向为杆管柱连接螺纹强度平度与优化分析。E-mail: jslx2004@163.com。
    第一联系人:易军*(通信作者),男,1987年生,博士、副教授。研究方向为复杂曲面零件高效精密加工。E-mail:yj_hnust@163.com。
  • 基金资助:
    中国博士后科学基金(2024M760850)

Effect of Geometric Defect Structures on Strength and Fatigue Life of Drill Tool Threads

LU Ye(), DING Yuqi(), LEI Zihuang, LYU Qilin, LI Zhichao, LI Kangjian   

  1. School of Mechanical Science and Engineering,Northeast Petroleum University,Daqing,Heilongjiang,163318
  • Received:2025-08-18 Online:2026-09-25 Published:2026-10-21
  • Contact: DING Yuqi

摘要:

以某双台肩钻具连接螺纹为研究对象,考虑缺陷结构对螺纹力学性能的影响,建立了能有效模拟上扣扭矩和复杂接触状态的钻具连接螺纹轴对称等效模型,开展了弯曲井段下螺纹结构的强度与疲劳寿命分析。计算结果表明:在给定上扣扭矩、内外压力、轴向载荷和弯矩的作用下,螺纹最大应力发生在内外螺纹啮合的第一圈齿根位置,经强度评定和疲劳分析,螺纹结构能够满足工程需求。当螺纹结构产生缺陷后,其最大等效应力总是出现在缺陷底部位置;缺陷位置距离外螺纹第一圈齿根越近,等效应力增幅越大,缺陷位置对等效应力的影响由大到小依次为首圈齿根、首圈齿廓根部、首圈齿廓中部。随着缺陷深度的增大,螺纹整体应力逐渐增大,当缺陷深度增至2.3 mm时,最大应力增大50.1%,疲劳寿命降低94.8%;随着缺陷宽度的增大,螺纹整体应力逐渐减小,但相较于无缺陷螺纹结构,宽度为1.6 mm时,最大应力仍然增大了34%,疲劳寿命降低了75.2%。

关键词: 钻具连接螺纹, 轴对称等效模型, 缺陷, 强度, 疲劳寿命

Abstract:

A double-shoulder drill tool connecting thread was selected as the research object. Considering the influence of defective structures on the mechanics properties of threads, an axially symmetric equivalent model of the drill tool connecting thread was established, which may effectively simulate make-up torque and complex contact states. Through this model, the strength and fatigue life analyses of the thread structure were conducted in curved well sections. The calculation results indicate that under the action of given make-up torque, internal and external pressure, axial load, and bending moment, the maximum stress of the thread is generated at the root of the first engaged thread of the internal and external threads. After strength evaluations and fatigue analyses, it is confirmed that the thread structure may meet engineering requirements. When defects are formed in the thread structure, the maximum equivalent stress is always concentrated at the bottom of the defect. The closer the defect is to the root of the first thread of the external thread, the more significant the increase in equivalent stress. The influence of defect position on equivalent stress ranks in descending order as follows: root of the first thread, root of the first thread profile, and middle of the first thread profile. With the increase of defect depth, the overall stress of the thread increases gradually. When the defect depth reaches 2.3 mm, the maximum stress is increased by 50.1%, and the fatigue life is reduced by 94.8%. As the defect width increases, the overall stress of the thread decreases gradually. However, compared with the non-defective thread structure, when the width is 1.6 mm, the maximum stress is still increased by 34%, and the fatigue life is reduced by 75.2%.

Key words: drill tool connecting threads, axially symmetric equivalent model, defect, strength, fatigue life

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