Accuracy analysis of a guardrail impact simulation based on ANSYS/LS-DYNA

The methods to improve accuracy and efficiency of a numerical simulation for guardrail impact via changing mesh density, number of integration points throughout thickness of a shell element, element formulation, contact type and hourglass formulation in virtue of ANSYS/LS-DYNA are studied here. The following conclusions can be drawn from analyses results; (1) denser mesh and more integration points can effectively evaluate and improve the accuracy of the numerical simulation, and the consumed time increases in terms of a power function with the variation of N/l and the number of integration points; (2) the calculation results of the B-T formulation are almost the same as those of the H-L formulation, and The calculation results of the B-W-C formulation are more safe if they are used for structural design; H-L, B-T and B-W-C formulations can be put in order from lower to higher calculation efficiency; (3) single contact can be regarded as the referene standard for its better calculation accuracy; the use of one-direction contact can raise efficiency through properly defining slave and master contact surfaces. Some proposals for defining slave and master contact surfaces and the corresponding explanations based on theoretical and practical experiences are presented.