LS-DYNA Implicit for Dent Performance Evaluation

Present day engineering design involves complex CAE analyses using both linear and non-linear methods. Mos companies use multiple software tools for different types of analyses. Several reasons, including cost are driving companies to investigate lesser number of FEA tools so that they can use a single solver for most of their structural analyses. LS-DYNA has been traditionally used for explicit analysis like crash and metal forming. Recent enhancements in the versions of LS-DYNA enable us to evaluate it for implicit analysis. The success of an automotive design is determined by its ability to meet the expectations of the customer with respect to cost, performance and styling. Dent performance is an important factor in designing automotive outer panels due to increased customer sensitivity to surface finish and durability. Dent performance is defined as the deflection under certain external loads at the panel outer surface. The external loads can be from many sources like shopping carts or from an adjacent vehicle door in a parking lot. Dent performance prediction assumes a quasi-static equilibrium solution eliminating the effects of inertia, thereby making it an implicit analysis. Dent prediction analyses are traditionally performed using specialized implicit solvers. In this study, LS-DYNA implicit was used to predict dent performance on several outer panels (doors & hoods). The results were then compared to the corresponding experimental results and to the results from a competing solver. This paper also describes the setup using Altair HyperMesh, various analysis parameters and element formulations used for dent analysis.