270 Three-point bending crack propagation analysis of cast iron beam subjected to eccentric impact loading by X-FEM

Delamination Buckling and Crack Propagation Simulations in Fiber-Metal Laminates Using xFEM and Cohesive Elements

“…A systematic numerical investigation was conducted in this study, using a total of three different models in order to establish the integrity of the xFEM and CZM facilities of LS-DYNA. First, a model that was analyzed by another investigator [1] was tried to validate the integrity of our approach. Then, since the configuration of the materials forming our 3D-FML is relatively complex, it was decided to initially simulate the response of the standard double cantilever beam to further hone our skill in using the xFEM and calibrate the properties required for conducing such analysis.…”

“…As briefly mentioned, the first trial involved simulation of the response of a simply-supported rectangular cross-section cast iron beam specimen subjected to an impact load at its mid-span using xFEM. The parameters required for xFEM simulation of the specimen were extracted from reference [1]. It should be noted that the efficient approach commonly used in simulating such simple 3D geometries is by modeling them as either 2D plane-stress or plane-strain geometry, depending on the aspect ratios of the specimen.…”

“…Consequently, LS-DYNA's shell elements (type 54 in conjunction with the fully integrated base element 16) were used to continue the modeling effort. It is reckoned that shell elements are not used conventionally to simulate such geometries (i.e., geometries with an appreciable thickness-to-depth ratio); nonetheless, an accurate fracture response could be successfully predicted in comparison to the experimental results reported by Tsuda et al [1] (who incidentally used the same approach in modeling the specimen's response). A detailed explanation of the modeling approach, as well as the discussion of the required parameters, are presented in the Appendix A.…”

“…The element erosion approach entails deleting elements based on an appropriate stress or strain criterion, therefore, leading to the formation of a crack path. It is the simplest of the mentioned methods but is significantly mesh-dependent, thus, often lacking accuracy [1].…”

“…Moreover, it is worth mentioning that there are a few studies that have compared the integrity of the three approaches when used in simulating crack propagation. For instance, Tsuda et al [1] used the erosion and xFEM elements of LS-DYNA for simulating the crack propagation resulting from the impact of a rectangular cast iron specimen in three-point bending configuration. The xFEM results were found to be in excellent agreement with the experimental results, while the erosion elements could not accurately simulate the experimentally observed response.…”