钢丝绳疲劳寿命评估与试验方案优化设计

发布时间：2018-04-26 23:10

本文选题：钢丝绳 + 失效判定　；参考：《国防科学技术大学》2015年硕士论文

【摘要】：钢丝绳广泛应用于工程领域,一旦发生故障将造成重大事故,对设备安全可靠服役具有至关重要的作用。研究钢丝绳的失效判定准则和疲劳寿命评估方法对提升国产钢丝绳性能、保障人身财产安全具有重要意义。本文从结构力学、数据分析和试验方案设计的角度着手,研究了钢丝绳失效判定与疲劳寿命评估的理论与应用。文章首先提出了复杂对称产品的完全对称化模型,在此基础上建立了钢丝绳层次失效判定方法,进而结合钢丝绳单丝单股整绳试验数据对钢丝绳层次失效判定方法进行了验证。基于层次失效判定方法的数据需求,本文还给出了钢丝绳疲劳寿命试验的优化设计的可行思路。本文的主要研究内容如下:1.结合解析与数值方法,提出了产品属于复杂对称构件时的失效判定通用模型,此模型不受产品材料、生产工艺和结构的限制,能准确计算产品两端承受载荷和产品构成件内部应力之间的关系,可广泛用于计算复杂对称结构的失效判定的力学分析问题。结合实际失效机理和层次失效判定方法对钢丝绳的失效准则进行了具体分析,并给出了可行的验证方案。2.以线接触填充型钢丝绳为例,应用钢丝绳的层次失效判定准则,结合具体的试验方案与试验数据,对完全对称化模型得到的单丝单股间的力学关系进行验证和修正。基于三维精确有限元分析进一步说明了模型的有效性和优越性,并给出了有限元疲劳寿命评估的分析方法,通过与层次失效判定方法对比,说明了有限元方法的缺陷。应用真实整绳冲击试验数据对钢丝绳整绳的载荷寿命曲线进行验证,并给出了在整绳疲劳寿命试验数据较少、试验难以开展的条件下,使用单丝和单股试验结果来推算整绳载荷寿命曲线的方案。3.根据钢丝绳层次失效判定分析结果,以钢丝绳单股为对象开展四个载荷水平下的恒定应力加速寿命仿真试验,并对试验方案进行优化设计。基于优化后单股的疲劳试验,结合钢丝绳层次失效判定的方法,可以针对相应的实际需求得到更合理精度更高的单股寿命评估结果,对于整绳的疲劳寿命评估也具有一定的指导意义。
[Abstract]:Wire rope is widely used in engineering field. Once failure occurs, it will cause serious accidents, which plays an important role in the safe and reliable service of equipment. It is of great significance to study the failure criterion and fatigue life evaluation method of steel wire rope to improve the performance of domestic wire rope and to ensure the safety of personal and property. From the point of view of structural mechanics, data analysis and test scheme design, the theory and application of failure determination and fatigue life evaluation of wire rope are studied in this paper. In this paper, a complete symmetry model of complex symmetric products is proposed, and a method for determining the failure of wire rope layers is established based on this model, and then the method of determining the failure level of steel wire rope is verified based on the test data of single wire strand and whole rope. Based on the data requirement of hierarchical failure determination method, this paper presents a feasible way to optimize the fatigue life test of wire rope. The main contents of this paper are as follows: 1. Combined with analytical and numerical methods, a general failure determination model for complex symmetric components is proposed. The model is not limited by the material, production process and structure of the product. It can accurately calculate the relationship between the two ends of the product under load and the internal stress of the components of the product. It can be widely used to calculate the mechanical analysis of the failure determination of complex symmetric structures. Combined with the actual failure mechanism and hierarchical failure determination method, the failure criterion of wire rope is analyzed in detail, and the feasible verification scheme is given. Taking wire contact filled wire rope as an example, applying the hierarchy failure criterion of wire rope, combining the concrete test scheme and test data, the mechanical relationship between single wire and single strand obtained by complete symmetry model is verified and corrected. The validity and superiority of the model are further illustrated based on 3D accurate finite element analysis, and the analysis method of fatigue life assessment of finite element method is given. The defects of the finite element method are illustrated by comparing with the hierarchical failure determination method. The load life curve of the whole wire rope is verified by using the real whole rope impact test data. Under the condition that the test data of the whole rope fatigue life is less and the test is difficult to be carried out, the load life curve of the wire rope whole rope is verified. Using single wire and single strand test results to calculate the load life curve of the whole rope. According to the results of hierarchical failure analysis of steel wire rope, the simulation test of constant stress accelerated life under four load levels is carried out with single strand of wire rope as the object, and the test scheme is optimized. Based on the fatigue test of single strand after optimization and the method of determining the failure of steel wire rope, a more reasonable and accurate single strand life evaluation result can be obtained according to the actual demand. It also has certain guiding significance for evaluating the fatigue life of the whole rope.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG356.45

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