If the change in magnitude of the stress doesn't exceed some value for a particular connection geometry, fatigue probably isn't going to be a problem. The influence on the geometry of the connection must also be considered.ĪWS D1.1 includes some information on fatigue. If the nature of the loading is always in compression, the change in magnitude may not be sufficient to result in fatigue. However, one must consider the magnitude of the change in stress and the number of cycles. In theory, even if the nature of the loading is compressive, repeated cycles of high compressive stress and low compressive stress can lead to fatigue. RE: Can fatigue cracks form under compression-compression stress cycles? gtaw (Structural) 1 Oct 21 16:20įatigue is influenced by the change in the magnitude of the cyclic loads. Is it possible for fatigue cracks to form in this situation? At the point under consideration, at least part of the stress cycle occurs in tension. Is this any different, then, to a situation where the stress cycles are in tension, but due to residual compressive stress in the element (such as from peening, or some other effect), the overall stress experienced is still always compressive?Īnd I suppose the opposite situation is where there is a residual tensile stress in the element, but the stress cycles are purely compressive.
However, I have no way of knowing if this is right. min and max stresses are both compressive), and that there are no residual stresses of any kind in the element (such from welding, hot rolling, plastic deformation, or whatever), is it possible for fatigue cracks to form? I have heard that the answer is "yes", but that the rate is in the order of 100x slower than in tension. Supposing that a steel element is subjected to purely compressive load cycles (i.e. So my experience with fatigue is less on the theoretical side and more on the code-based side. I have heard conflicting answers to this question before, and I have to say that my background is not in materials but in structural engineering.
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