Critical Issues Related to the Effect of Residual Stresses on MixedMode Crack Growth Phenomenon M. Saribay∗ Department of Mechanical Engineering, Istanbul Bilgi University, Istanbul 34060, Turkey ∗ murat.saribay@bilgi.edu.tr Keywords: computational fracture, residual stresses, mixed-mode crack growth. Manufacturing methods that include welding processes might carry a structural failure risk due to residual stress effects. This type of potential failure could be misleading for the analysis of a component subjected to a subsequent load following the welding process. If the problem involves crack propagation phenomenon with fatigue loading, then the overall investigation becomes much more complicated to handle. An effective finite element program [1] for the solution of fracture problems with stationary crack fronts was introduced to the literature in the past. Later, the capabilities of this program were further improved [2] by including crack growth procedures. On the other hand, a notable work [3] analyzed the effect of residual stresses on post-welding behavior of cracked structures, but only considered stationary cracks. Current study demonstrates the features of a recently developed computational tool for understanding the effects of residual stresses on mixed-mode crack growth analysis. In such problems, several issues such as correct modeling of welding simulation, adequate representation of the model details in finite element mesh, estimation of propagation direction, a suitable growth law, determination of an optimum crack increment size, remeshing procedures are among significant matters. Geometrical variations are considered by depicting example problems with both straight and curved crack fronts. It is seen that all issues given above have key roles for the accurate simulation of growing cracks with residual stresses. It should also be noted that neglection or underestimation of residual stress effects might lead to wrong conclusions regarding the fracture output for a particular example. As a follow-up task, the effect of welding parameters on the same problem is being considered. References [1] Ayhan, A. O., Nied, H. F. (2002). Stress intensity factors for three-dimensional surface cracks using enriched finite elements. Int. J. Num. Meth. Eng., 54, 899-921. [2] Saribay, M., Hadri, Z., Rakotomola, N., Marechal, E. Nied, H. F. (2019). Unresolved issues associated with the simulation of 3-D fatigue crack growth in complex geometries. Special Symposium in Memory of Paul Paris, Society of Engineering Science. St. Louis, MI. [3] Saribay, M. (2020). Local and global energy densities associated with welding residual stresses of cracked structures. 62
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