Probabilistic analysis of damage accumulation with special regard to building structures stressed by collectives with higher number of cycles

损伤累积的概率分析，特别是受循环次数较多的集体应力的建筑结构

• 批准号: 252979423
• 负责人: Professor Dr.-Ing. Karsten Geißler
• 金额: --
• 依托单位: Fachgebiet Entwerfen und Konstruieren - Stahlbau
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/252979423?language=en
• 关键词: Probabilistic; analysis; damage; accumulation; special

The variance oft the real damage sum in the case of stress collectives depends on the variance of material and fabrication properties and additional on the accuracy of the used Miner-rule for determination of damage. At the field of civil engineering a limit damage sum of 1.0 is still usual, at other fields other limit damage sums are usual. A complete probabilistic concept of the damage accumulation under stress collectives, from the variance of Woehler-curve to the resulting variance of the limit damage (D_tat), additional depending on the used Miner-Rule, was developed at the former DFG-project. At this project the resulting safety elements were analyzed by systematic calculations for a small range of influence parameters, because of test results were only for some collectives available. Based on the results following further necessary aspects were recognized. It’s necessary to analyze the typical parameters of structural engineering as bridges and wind turbine constructions, especially for collectives with a low relation of the maximum to the threshold stress value (∆σ_max/∆σ_D), with a high number H ̅ and also other stress relations (R ̅ between 0 and 0.5). At the result other design values of the main influence parameters were expecting, additional explicit depending on the used Miner-rule. Furthermore it is focused to analyze the influence of the targeted safety index (ß_tar = 1,5…3,8) to the design values. Following sub-goals are provided: - Fatigue tests with collectives typical for structural engineering with regard to the accuracy of life time predictions, - Extension of the results within the concept for probabilistic damage calculation with special regard to the parameters which are typical for structural engineering, - Systematic analyze of the influence of the targeted safety index to the design values.

在应力集中的情况下，实际损伤总和的变化取决于材料和制造性能的变化，以及用于确定损伤的Miner规则的准确性。在土木工程领域，极限损伤总和仍然是通常的1.0，在其他领域，其他的极限损伤总和是常见的。从Woehler曲线的方差到极限损伤的结果方差(D_Tat)，在以前的DFG项目中，根据所用的Miner规则，发展了一个完整的概率概念，即在应力集体作用下的损伤累积。在这个项目中，由于试验结果只针对一些可用的集体，因此通过对小范围影响参数的系统计算来分析产生的安全元件。根据结果，确认了以下进一步必要的方面。对于桥梁、风力机结构等结构工程的典型参数，特别是最大应力与门槛应力之比(∆σ_max/∆σ_D)较低、H_̅值较大以及其它应力关系(R_̅在0~0.5之间)的集合体，有必要进行分析。在计算结果中，主要影响参数的其他设计值是预期的，附加显式取决于所用的Miner准则。此外，重点分析了目标安全指数(？TAR=1，5…)的影响3、8)到设计值。提供了以下子目标：-就寿命预测的准确性与结构工程的典型集体进行疲劳试验，-在概率损伤计算的概念内扩展结果，特别是关于结构工程的典型参数，-系统地分析目标安全指数对设计值的影响。