Experimental and numerical investigations on the failure behavior of metal skin and carbon fiber-reinforced polymer core structures considering layup and manufacturing process conditions

In this paper, the failure mechanism of metal skin (MS) and long carbon fibers reinforced core (CFRP) structures is investigated by means of tensile and bending tests, scanning electron microscope image analysis, and finite element simulations. For the failure modeling, a ductile damage model has been utilized for the MS, a traction separation model for the adhesive layers, whereas a modified Tsai-Hill criterion under the orthotropic assumption has been employed for the CFRP core. To verify the reliability of the proposed approach in predicting the failure of more complex MS-CFRP structures, experimental and numerical load-stroke curves relevant for two hat-shaped specimens, manufactured with two different MS, have been compared, showing a maximum deviation in the maximum load equal to 3.5%. The methodology proposed in this paper shows a systematic and reliable approach for the investigation of the fracture behavior of metal-composite structures, to be utilized for the design phase.

Automated summary

This paper investigates the failure mechanism of metal skin and long carbon fibers reinforced core structures through tensile and bending tests, SEM image analysis, and finite element simulations. Different models are utilized for the MS, adhesive layers, and CFRP core, with experimental and numerical comparisons showing a maximum deviation of 3.5% in maximum load, verifying the reliability of the proposed approach.