• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2019, Vol. 55 ›› Issue (6): 1-10.doi: 10.3901/JME.2019.06.001

• 特邀专栏:焊接力学与结构设计 •    下一篇

基于等承载思想的低匹配T型接头设计

郭军礼, 董志波, 刘雪松, 王苹, 方洪渊   

  1. 哈尔滨工业大学先进焊接与连接国家重点实验室 哈尔滨 150001
  • 收稿日期:2018-04-02 修回日期:2018-07-18 出版日期:2019-03-20 发布日期:2019-03-20
  • 通讯作者: 董志波(通信作者),男,1975年出生,博士,副教授,博士研究生导师。主要研究方向为焊接过程数值模拟与仿真技术、焊接结构可靠性及寿命预测。E-mail:dongzhb@hit.edu.cn
  • 作者简介:郭军礼,男,1987年出生,博士研究生。主要研究方向为焊接结构力学及可靠性分析。E-mail:iamgjl@163.com
  • 基金资助:
    国家自然科学基金资助项目(51875131)。

Design of Undermatching T Joints Based on the Thought of Equal Load Carrying Capacity

GUO Junli, DONG Zhibo, LIU Xuesong, WANG Ping, FANG Hongyuan   

  1. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001
  • Received:2018-04-02 Revised:2018-07-18 Online:2019-03-20 Published:2019-03-20

摘要: 针对低匹配焊接接头承载能力不足的问题,基于等承载思想建立等承载基本理论,通过定义广义匹配比和广义力学集中系数,提出广义力学集中系数与广义匹配比相等为等承载的实现条件。构建等承载设计的一般方法:明确接头失效形式,确定目标失效模式;确定接头危险位置;构建承载能力与几何参数、材料力学性能关系式;分别求解焊缝临界曲线并取包络线。以承受静拉伸的T型接头为例验证了以上方法的可行性:失效形式为静载断裂,按照全面屈服(焊缝)断裂模式进行设计,给出明确的实现条件;建立理论应力集中系数与几何参数的关系式;结合T型接头几何特点给出求解步骤;建立等承载T型接头弹塑性有限元模型,接头的断裂模式为全面屈服(焊缝)断裂,承载能力达到了母材的屈服水平。结果表明等承载基本理论和方法具有一定的普适性,能为更多的焊接接头等承载设计问题提供解决方案。

关键词: T型接头, 等承载, 低匹配, 理论, 设计方法

Abstract: To improve the load-carrying capacity of undermatching joints,the basic theory of equal load-carrying capacity (ELCC)design is established based on the thought of ELCC. The concepts of generalized mechanics concentration factor(GMCF) and generalized mis-match ratio (GMMR)are defined, so the realization condition of ELCC is presented, i.e.make GMC Fequal to GMMR. The general approach of ELCC design is proposed:① ascertain the failure form of joints, determine the target failure mode; ② determine the failure position; ③ obtainthe relational expression betweenload carrying capacity and geometrical parameters, mechanical properties of materials; ④ obtain the critical curve of weld seam respectively, then take the envelope curve as the final solution. According to the procedure proposed, the ELCCTjoints with tensile load are designed. The failure form is static load fracture, the target failure mode isoverall yield (weld seam) fracture mode, thenthe realization condition of ELCC is specialized. Calculate the theoretical stress concentration factorof different geometric parameters through numerical method,establish the equation of them, then put forward the equal load-carrying capacity design strategy for T-joint joints. An elastic-plastic finite element model of one ELCC T-joint is built, and results show that the joint fractures in overall yield (weld seam) fracture model, its load-carrying capacity reachesthe yield strength of base metal.The results indicate that the theory and approachproposedarefeasible and can provide solutions to more ELCC problems.

Key words: design method, equal load carrying, T joints, theory, undermatching

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