导　　师： 张海鸥

学科专业： 080503

授予学位： 博士

作　　者： ;

机构地区： 华中科技大学

摘　　要： 钢丝绳是一种重要的空间螺旋结构制品,具有高强度、柔软性和稳定可靠的特点,因而被广泛地应用于机械、建筑、交通、通讯和航空航天等领域。到目前为止,大量文献研究了钢丝绳承受拉伸、弯曲和扭转载荷时的变形情况,但很少有对钢丝绳成形过程进行数值模拟的研究,特别是没有考虑自扭转系数和接触摩擦对捻制成形影响。捻制成形过程中变形复杂,必须同时考虑材料非线性和接触非线性。钢丝绳的加工应力不仅影响成形性,而且由其引起的残余应力对钢丝绳结构强度有很大影响。因此,本文进行了钢丝绳成形过程数值模拟和制品力学强度分析的研究工作。 本文首先建立了考虑自扭转系数时的钢丝绳空间几何模型,该模型是捻制成形过程有限元计算模型的重要组成部分;根据钢丝绳捻制成形原理,考虑捻制成形中的材料非线性,以虚功原理为基础,建立了捻制成形数值模拟中弹塑性增量分析的有限元方程。 接触摩擦模型是捻制成形过程有限元计算模型的另外一个重要组成部分。接触摩擦与钢丝绳变形之间是复杂的非线性关系,直接影响着钢丝绳的成形性。接触摩擦问题的处理包括接触单元的搜索和接触力的计算两个方面。本文采用捻制成形中三维Splitting-pinball接触搜索计算模型,该算法大大提高了搜索接触单元的精确性。 采用罚函数法,讨论了接触界面本构关系的增量形式和接触单元技术,用径向回映算法处理接触摩擦中的粘着//滑动状态;在罚函数法的基础上,进一步给出了采用Augmented Lagrangian法处理法向接触力和切向接触力的计算模型。该方法的优点是可以得到问题的精确解,且节约CPU消耗时间和减少控制方程出现病态。 为了考虑捻制成形工艺对钢丝绳结构强度的影响,本文建立了钢丝绳制品力学强度分析计算模� Metal wire rope is an important kind of space spiral product. Since it has the characteristic of high strength, flexibleness and stability, it is widely applied in many fields, such as mechanism, architecture, transport, communication, aviation and aerospace, etc. Up to now, although the behaviors of stranded rope under loads, including tension, shear, bending and torsion, have been studied in many literatures, little information is available to predict the simulation for the laying process of wire rope, especially without regard to the self-rotating ratio and friction contact condition. Material non-linearity and contact non-linearity must be considered for the complicated deformation of laying wire rope. The formation stress affects the formability of wire rope, and the resultant residual stress greatly affects the structural strength. So the research of numerical simulation on the laying process and strength analysis of wire rope has been carried out in this paper. The space geometric model of wire rope with self-rotating ratio has been described and the model is an important component of finite element computation model for laying wire rope. Taking the laying process theory of wire rope and material non-linearity into consideration, and based on the principle of virtual work, elasto-plastic incremental FE equations have been established for the numerical simulation for laying wire rope. Friction contact model is another important component of finite element computation model for laying wire rope. It is a complicated nonlinear relationship between friction contact and deformation of wire rope. And friction contact has direct effect on the formability of wire rope. Friction contact routines carry out two tasks: to search the contact elements being in contact and to compute the contact forces. 3D Splitting-pinball contact searching model for laying wire rope has been adopted, and the accuracy has been improved by the Splitting-pinball algorithm. Using penalty method, the incremental co

关 键 词： 钢丝绳捻制成形 接触摩擦 三维小球分裂算法 修正的拉格朗日乘子法 应力应变 强度 自扭转系数

领　　域： [金属学及工艺]