多部位损伤零部件可靠性建模方法与软件开发

发布时间：2018-05-01 17:14

本文选题：多部位损伤 + 相关失效　；参考：《东北大学》2014年硕士论文

【摘要】：对于工程中的大部分零件的多个薄弱环节,即多部位损伤(MSD—Multiple-Site Damage),当其受到同一随机载荷的作用时,其失效一般不是相互独立的,载荷的分散性是导致各损伤部位之间存在相关失效的根本原因。如果不考虑损伤部位之间存在的失效相关性,计算多部位损伤零部件可靠度时,结果往往会出现较大的误差,甚至是错误的结果。因此,在进行多部位损伤零部件的可靠性建模中,应该考虑失效相关性对零件可靠度的影响。在零件各损伤部位所受应力、自身强度均服从三参数威布尔分布的条件下,本文以可靠性应力—强度干涉模型为基础,并根据随机抽样的反变换法,建立多部位损伤零部件的静态可靠度评价模型。在多部位损伤零部件静态可靠度评价模型的基础上,对载荷多次作用以及损伤部位强度退化两个因素进行思考,建立多部位损伤零部件的动态可靠性评价模型。根据考虑因素的不同还可建立两个不同的评价模型,模型如下(1)单独考虑载荷对损伤部位进行多次作用时对多部位损伤零部件可靠性的影响。通过随机载荷的次序统计量,得到随机载荷进行多次作用时的等效载荷。在损伤部位强度不会发生退化,或在允许范围内,强度退化极小的条件下,建立损伤部位在考虑载荷作用次数条件下的多部位损伤零部件动态可靠性模型。(2)除了载荷作用次数的影响,还应考虑强度退化对多部位损伤零部件可靠度的影响。基于剩余强度退化规律,对于已经受到n次载荷作用的零部件,其可靠度为载荷下一次作用时,零部件不失效的概率。从而建立同时体现载荷多次作用和强度退化这两个因素的多部位损伤零部件可靠度评价模型。使用蒙特卡罗方法对所建立的模型进行数值模拟仿真验证。本文以多孔结构件为例,基于有限元建立有关结构件的模型并对结构件进行可靠性分析。通过matlab软件的GUI功能,开发可靠度计算软件,对所建立的可靠性评估模型进行估算从而得到多部位损伤零部件可靠度。
[Abstract]:For many weak links of most parts in engineering, that is, MSD-Multiple-Site damage, the failure of MSD-Multiple-Site damage is not generally independent of each other when it is subjected to the same random load. The dispersion of load is the root cause of the related failure among the damage sites. If the failure correlation between the damaged parts is not taken into account and the reliability of the damaged parts is calculated, the results will often lead to large errors or even wrong results. Therefore, the effect of failure correlation on reliability should be considered in the reliability modeling of multi-site damaged parts. Under the condition that the stress of each damaged part is subject to the Weibull distribution of three parameters, this paper is based on the reliability stress-strength interference model, and according to the inverse transformation method of random sampling, The static reliability evaluation model of multi-site damaged parts is established. Based on the static reliability evaluation model of multi-site damaged parts, the dynamic reliability evaluation model of multi-site damaged parts is established by considering two factors: the multiple loads and the strength degradation of the damaged parts. According to the different factors, two different evaluation models can be established. The model is as follows: 1) considering the effect of load on the reliability of the parts with multiple damage parts. By using the order statistics of random loads, the equivalent loads are obtained when the random loads are subjected to multiple actions. Where the strength of the damaged site does not degrade, or where the intensity degradation is minimal within the allowable range, The dynamic reliability model of multi-site damaged parts considering the number of loads is established. In addition to the influence of the number of loads, the influence of strength degradation on the reliability of multi-site damaged parts should be considered. Based on the law of residual strength degradation, the reliability of parts which have been subjected to n times of load is the probability of no failure of the parts under the next action of the load. Thus the reliability evaluation model of multi-site damage parts is established, which reflects the two factors of multiple loads and strength degradation. Monte Carlo method is used to simulate the model. In this paper, taking porous structure as an example, the model of relevant structural parts is established based on finite element method and the reliability analysis of structural parts is carried out. Through the GUI function of the matlab software, the reliability calculation software is developed, and the reliability evaluation model is estimated to get the reliability of the damaged parts.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB114.3

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