Calibration and experimental validation of LS-DYNA composite material models by multi objective optimization techniques
Numerous authors have documented efforts over the past two decades to understand the complex behavior of laminated composite structures under transient loading conditions.
CHALLENGE - These efforts were made to identify and characterize the relevant failure mechanisms, to understand their interactions, and to be able to predict the extent of damage within a given composite system under a set of specified loading conditions. In this example, the virtual prototyping procedure is tested to design and to predict reliability crashing behavior of motorcycle protective equipments.
SOLUTION - The procedure adopted an integrated experimental-numerical method for the calibration of LS-DYNA input parameters for material model 58 and 63, by means of the integrated platform modeFRONTIER. Material model 58 was used for modelling woven fabrics while material model 63 was used for crushable foam modelling.
RESULTS - The multi-objective analysis demonstrates a good compliance, with a delta less than 5% between numerical and experimental results for all the reference parameters and the curve morphology in case of pure composite samples whereas a delta of 6 % for the worst sandwich configuration is found. This approach allows defining only one set of reduction factors for each material: This means that the correct way to approach the definition of material input parameters for composites in LS-DYNA is to calibrate the reduction factors via numerical drop test simulations.