Calibration and Experimental Validation of LS-DYNA Composite Material Models by Multi Objective Optimization Techniques

Experimental quasi-static tensile and impact tests were conducted over two different types of composite laminates and four different types of sandwich laminates, in order to evaluate their basic mechanical characteristics and energy adsorption capability. The second phase of this research work approaches and resolves the calibration of the mechanical parameters included into the LS-DYNA composite material models. This calibration starts and is based on the material physical properties derived from the test results. LS-DYNA model parameters, model constrains and objectives defining the problem have been studied and analysed by using modeFRONTIER. modeFRONTIER is a multi-objective and multi-disciplinary integrated platform. Input parameters were varied into a controlled range. This allows to find quickly and to define accurate model configuration as well as model sensitivity to those parameters, leading to reliable numerical models for impact simulations. Accurate comparison of simulation results with experimental material results is crucial to achieve optimum and precise material models. The present research study offers also an understanding of the effect of numerical input parameters and variables on sandwich laminates structural response in terms of absorbed energy, maximum energy, maximum force and curve morphology. Calibration of material models, able to reproduce the effective impact behaviour of real composite materials, is fundamental in order to simulate general crashworthiness problems. This kind of approach allows either to understand variable influences on composite dynamic structural response or to get improved solution for industrial case studies.