Inward eccentric fold failure in the progressive crushing of aluminum-CFRP square hybrid tubes

To explore the enhancement mechanism of CFRP overwrap in the aluminum-CFRP square hybrid, hybrid tubes with different braided angles were investigated both experimentally and numerically. Hybrid tube of 30 degrees had severe CFRP layers splitting damage in the tube corner. As the braided angle up to 60 degrees, CFRP layers with high transverse resistance force compressed the aluminum tube and caused it to fold inward; This led to the hybrid tube failing in a distinct inward eccentric fold deformation pattern and had an obvious energy absorption improvement in its inner aluminum tube due to its increase in the corner deformation.