Christ Hans-Jürgen
Institut für Werkstofftechnik, Universität Siegen, Germany.
Stud Health Technol Inform. 2008;133:56-67.
A brief overview is given in this article on the main design philosophies and the resulting description concepts used for components which undergo monotonic and cyclic loading. Emphasis is put on a mechanistic approach avoiding a plain reproduction of empirical laws. After a short consideration of fracture as a result of monotonic loading using fracture mechanics basics, the phenomena taking place as a consequence of cyclic plasticity are introduced. The development of fatigue damage is treated by introducing the physical processes which (i) are responsible for microstructural changes, (ii) lead to crack initiation and (iii) determine crack propagation. From the current research topics within the area of metal fatigue, two aspects are dealt with in more detail because of their relevance to biomechanics. The first one is the growth behaviour of microstructural short cracks, which controls cyclic life of smooth parts at low stress amplitudes. The second issue addresses the question of the existence of a true fatigue limit and is of particular interest for components which must sustain a very high number of loading cycles (very high cycle fatigue).
本文简要概述了用于承受单调和循环载荷的部件的主要设计理念以及由此产生的描述概念。重点是一种机械方法，避免简单地复制经验定律。在使用断裂力学基础对单调载荷导致的断裂进行简短考虑之后，介绍了由于循环塑性而发生的现象。通过引入负责微观结构变化、导致裂纹萌生以及决定裂纹扩展的物理过程来处理疲劳损伤的发展。从金属疲劳领域当前的研究课题中，由于其与生物力学的相关性，有两个方面将更详细地进行探讨。第一个方面是微观结构短裂纹的扩展行为，它控制着低应力幅值下光滑部件的循环寿命。第二个问题涉及真正疲劳极限的存在问题，对于必须承受大量加载循环的部件（超高周疲劳）尤为重要。
