Entwicklung eines Lebensdauervorhersagekonzepts im VHCF-Bereich auf der Basis kovariater mikrostruktureller Merkmalsgrößen

期望项目的目的是研究疲劳寿命预测概念的统计模型和方法，尽可能准确，并在vhcf范围内进行实验验证。关于两种结构材料（镍基高温合金Nimonic 80A和奥氏体钢1.4301）的VHCF行为，已有的和额外的疲劳结果和显微组织分析可以作为数据库。所提出的数学研究工作一般归于考虑协变量信息的极值理论领域。协变量信息与控制失效的微观结构特征有关（例如最大夹杂物尺寸、邻近晶粒的取向错误、表面粗糙度等）。利用极值理论，试样疲劳寿命的条件分布取决于施加的应力幅值，以及复杂的协变量，应模拟和拟合到所获得的数据。因此，为适当的风险参数（如应力和失效循环次数）的发展提供了充分的证据基础，作为众所周知的sn曲线的基础。统计模拟和实验研究之间的密切联系是该项目的核心部分。两种结构材料在VHCF范围内的实验结果应立即进入统计建模，得到的结果应用于实验设计。

The aim of the desired project is the study of statistical models and methods for a fatigue lifeprediction concept with the utmost possible accuracy as well as its experimental validation in theVHCF range. Already available and additional fatigue results and microstructural analysesregarding the VHCF behavior for two structural materials, the Ni-base superalloy Nimonic 80A undthe austenitic steel 1.4301, serve as database. The proposed mathematical research work cangenerally be attributed to the field of extreme value theory under consideration of covariateinformation. The covariate information relates to failure-governing microstructural features (e.g.maximum inclusion size, misorientation of neighboring grains, surface roughness etc.). Using theextreme value theory the conditional distribution of a specimen fatigue life depending on theapplied stress amplitude as well as complex covariates should be simulated and fitted to the dataobtained. Hence, a basis for the development of well-grounded evidences for appropriate riskparameters such as stress and number of cycles to failure as basis for the well-known SN-curve iscreated. The close link between the statistical simulation and experimental investigations is acentral part of the project. The experimental results for two structural materials in the VHCF rangeshould immediately enter into the statistical modeling, and the obtained findings should be used forthe design of experiments.