Advanced Evaluation of Fatigue Phenomena Using Non-Destructive Testing Methods
Advanced Evaluation of Fatigue Phenomena Using Non-Destructive Testing Methods
复制标题
使用无损检测方法对疲劳现象进行高级评估
DOI：
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发表时间：
2016
期刊：
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通讯作者：
C. Boller
中科院分区：
文献类型：
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作者：
P. Starke;Haoran Wu;C. Boller
由于施加载荷而引起的金属材料微观结构变化的综合表征对于理解基本疲劳机制或更一般的损伤演化过程至关重要。如果这些机制和过程要理解到更大的程度，先进的疲劳寿命计算方法是远离线性损伤累积模型，必须实现提供更多的“经典疲劳数据”。其中包括PHYBAL（基于物理的疲劳寿命计算）方法，包括当前的增强和基于此的开发命名为SteBLife（步进杆疲劳寿命方法）已经在过去的10年中开发。这些方法可以减少90%以上的实验工作量，因此可以考虑更多的疲劳相关参数。因此，这允许利用容易建立多维数据集的那些方法生成依赖于那些疲劳相关参数的各种S，N曲线。仅举几个这些参数的例子，例如温度、载荷条件、几何形状以及热老化和机械老化过程对疲劳性能的影响，现在可以根据一个简单的过程来计算，从而在提高评估结构部件的效率方面迈出重要的一步。因此，安全系数可以更多地根据结构需求来确定，这对于越来越多的老化基础设施（如公路、桥梁或其他）来说是最重要的。许多这种老化的基础设施都迫切需要对其结构完整性进行管理，因此工程界试图尽可能适当地确定这种基础设施的剩余寿命。在这种情况下，非破坏性测试参数越来越多地被认为是表征金属材料的微观结构，允许获得关于实际损坏状况和部件完整性的更精确的信息。本文将讨论高性能的无损检测技术的损伤演化过程的评估也相对于基于机制的疲劳以及剩余寿命计算，根据PHYBAL和SteBLife。
The comprehensive characterization of the change in metallic materials’ microstructure due to an applied load is of prime importance for the understanding of basic fatigue mechanisms or more general damage evolution processes. If those mechanisms and processes are to be understood to a much greater extent, advanced fatigue life calculation methods being far away from linear damage accumulation models, have to be realized providing more than “classic fatigue data” only. Among others the PHYBAL (physically based fatigue life calculation) method including current enhancements and a thereon-based development named SteBLife (step-bar fatigue life approach) have been developed over the last 10 years. These methods allow the efforts in experimentation to be reduced by more than 90 % and therefore offer the possibility to take further fatigue relevant parameters into account. This therefore allows a variety of S,N-curves dependent on those fatigue relevant parameters to be generated with those methods easily establishing a multidimensional dataset. To just name a few examples of those parameters such as the influence of temperature, loading conditions, geometry as well as thermal and mechanical ageing processes on the fatigue behavior can now be calculated in accordance to a process being straightforward leading to an important step with regard to improving the efficiency of assessing structural components. Consequently, safety factors can be defined more in accordance to structural needs, being of highest interest with respect to the increasing number of ageing infrastructure such as highways, bridges or others. A lot of this ageing infrastructure has a strong need to be managed with respect to its structural integrity and the engineering community therefore tries the residual life of this infrastructure to be determined as appropriate as possible. In that context non-destructive testing parameters are increasingly considered to characterize a metallic material’s microstructure allowing more precise information to be obtained regarding the actual damage condition and the integrity of a component. The paper will address the high capability of non-destructive testing techniques for the evaluation of damage evolution processes also with respect to mechanism based fatigue as well as residual life calculations according to PHYBAL and SteBLife.