The Multi-Scale Modeling of Failure of Continuous Fiber Composites for Virtual Allowables

The last 50 years saw the development of mechanical simulation thanks to the growth of computers. This development was originally boosted by the industrial production of metal parts. It yielded technologies subsequently applied to new materials such as continuous fiber composites with uneven success and consecutive suboptimal designs. Indeed, such materials exhibit much different properties than metals. In particular, their nonlinearity and anisotropy are not straightforward to take into account in simulations. Moreover their properties vary through space (within a given part) and time depending on the manufacturing process and the operating environment. This variability is actually driven by the material constituents properties and microstructure i.e., the amount, shape and orientation adopted by the fibers at the core of the composite. Hence the name of the game in composite material modeling – and the strategy applied by e-Xstream engineering since 10 years – consists in enriching simulations with such microstructural information. This multi-scale modeling strategy will be addressed in this paper, focusing on strength prediction of continuous fiber composite coupons.

Multi-scale modeling combines micromechanics and damage evolution to simulate complex failure events in the composite material system. It enables the virtual characterization of failure of continuous fiber composites.  Combined with a relevant progressive failure mechanism, it contributes to the virtualization of unidirectional coupon tests, routinely performed in the aerospace industry to collect design allowables. Hence multi-scale modeling streamlines composite material deeper understanding and wider usage.