Process Integration and Optimization of ICME Carbon Fiber Composites for vehicle lightweighting: a preliminary development

Hongyi Xu, Yang Li, and Danielle Zeng (Ford Motor Company)

CHALLENGE Different from the Sheet Molding Compounds (SMC) structure, the unidirectional (UD) structure (laminate) has multiple layers, and each layer has anisotropic properties. Along the fiber direction, the single layer of UD sheet has the highest Young’s modulus and the highest strength; along the perpendicular direction, the single layer of UD sheet has the lowest Young’s modulus and the lowers strength. In this paper, a UD structure’s “layout” is defined as the number of layers, and the fiber orientation of each layer. The layout of each component in the vehicle structure needs to be optimized in order to achieve the optimum structure performance such as stiffness, durability, NVH, and safety.

SOLUTION The multi-layer UD structure optimization is implemented on the platform of modeFRONTIER.  At the top of the workflow, the design variable vectors are defined for each part. One vector defines the fiber orientation of each layer, and the other vector defines the thickness (0 or 0.4 mm) of each layer. Then the NASTRAN simulation input file is generated by the MATLAB script, based on the design variable values. The last step is to submit the simulations onto HPC, conduct post-processing, and obtain the responses (weight and stiffness). ​​

BENEFITS NSGA-II algorithm is used for the optimization.​ The population size is 50, and the number of total generations is 200. 10000 designs are generated in the entire optimization history.​ The optimum design found is 15.84 kg.