螺纹结构精确有限元建模及有效性分析  

Accurate Finite Element Modeling and Validity Analysis of Thread Structure

作　　者：李九一 周丰峻 张鏖 孙云厚 雷志刚 朱精忠 LI Jiuyi;ZHOU Fengjun;ZHANG Ao;SUN Yunhou;LEI Zhigang;ZHU Jingzhong(Inst.of Defense Eng.,AMS,PLA,Beijing 100850,China;Security and Protection Dept.of Public Security Ministry,Beijing 100850,China)

机构地区：[1]中国人民解放军军事科学院国防工程研究院,北京100850 [2]公安部特勤局,北京100850

出　　处：《工程科学与技术》2022年第3期220-229,共10页Advanced Engineering Sciences

基　　金：国家自然科学基金项目(51774295,51808551)。

摘　　要：由于螺纹复杂的几何结构,在对螺纹部件进行有限元分析时,螺纹部件的内外螺纹面往往难以啮合,常造成螺纹结构有限元建模困难、模型数值计算收敛性差等问题。本文基于垂直于螺纹轴线的任意横截面几何形状相同的事实,选取国际标准化组织(International Organization for Standardization,ISO)制定的标准螺旋线公式,采用3维8节点单元,精确建立了螺纹连接件有限元模型。该模型不仅考虑了螺纹螺旋升角对模型的影响,且模型中组成每个节距的单元层排列整齐,每层单元上的节点编号分布有序,内外螺纹面上的节点相互贴近。这些特质使得模型能够准确映射工程中螺纹连接结构的力学特性,优化模型数值计算收敛性,便于对模型数值计算结果开展力学剖面分析。为验证本文螺纹连接结构有限元建模方案的有效性,首先,在理论分析方面对螺纹连接结构中拧紧转角与轴向力的关系和螺纹连接结构中轴向力的分布进行了计算推导,并以M12标准螺栓为例,计算其轴向力分布。然后,通过数值模拟的方法先后验证了该螺纹连接结构拧紧转角和轴向力关系与理论分析结果的一致性、M12螺栓的轴向力分布与理论计算结果的一致性、螺纹齿根处应力集中系数状态与实验结果的一致性,以及应力分布和塑性应变分布与实际工程测量的一致性。基于螺纹连接结构有限元模型生成的方案开发了一款螺栓螺母有限元参数化建模软件,软件可根据输入的螺纹直径、节距数量等参数快捷地查看和生成不同型号的螺栓螺母3维有限元模型;在工程分析和优化设计中,使用该软件既避免了设计人员繁琐的重复劳动,又提高了设计精度和工作效率,能更好地满足实际工程需要。Due to the complex geometric structure of screw thread,it is difficult to mesh the internal and external screw surfaces of screw thread parts in the finite element analysis of screw thread parts,which often leads to difficulties in finite element modeling of screw thread structure and poor convergence of numerical calculation.In this paper,based on the fact that the geometry of any cross section of the thread perpendicular to its axis is the same,the standard helix formula formulated by the International Organization for Standardization(ISO)is selected,and the three-dimensional eight node element is used to accurately establish the finite element model of the threaded connector.The model not only considers the influence of screw thread elevation angle on itself,but also arranges the element layers of each pitch in order,the node numbers on each layer are orderly distributed,and the nodes on the internal and external screw thread surfaces are close to each other.These characteristics enable the model to accurately map the mechanical properties of threaded connection structures in engineering,optimize the convergence state of numerical calculation of the model,and facilitate the mechanical profile analysis of the calculated results.To verify the validity of the established finite element modeling method of threaded connection structure,the relationship between tightening angle and preload force in screw structure,the distri-bution of axial force in screw structure are deduced and theoretically analyzed,and the axial force distribution of M12 standard bolt is calculated as an example.The results of numerical experiments show that the relationship between the tightening angle and the preload of the screw connec-tion structure is consistent with the theoretical analysis results,the axial force distribution of M12 bolt is consistent with the theoretical calcula-tion results,the stress concentration coefficient at the root of the thread is consistent with the experimental results,the stress distribution and plastic stra

关 键 词：螺纹连接件 有限元法 参数化建模 有效性分析 

分 类 号：TH112[机械工程—机械设计及理论]