The Influence of Trigger Angle Structure on the Energy Absorption Capabilities of Aluminum Alloy/Thermoplastic Reinforced Polypropylene Hybrid Tubes

Fiber/metal hybrid tubes are significantly lighter and offer better energy absorption properties than traditional pure metal or fiber tubes, they are prone to instability and local buckling under multi-angle extrusion. The article describes the development of aluminum alloy (Al)/thermoplastic reinforced polypropylene (CFPP) hybrid tubes with different trigger angles through the finite element simulation and test combined research method. For various trigger angle configurations, the effects of axial and multi-angle loading on damage and energy absorption properties are examined. The introduction of a trigger angle enables progressive load distribution, with the inner aluminum alloy layer and CFPP layer making initial contact and being quickly destroyed, effectively reducing the initial peak load. A well-designed trigger angle length facilitates the gradual failure of the entire structure. When the trigger angle is 45°, load distribution is more even, resulting in better energy absorption performance. Under multi-angle conditions, composite tubes, whether with or without a trigger angle, tend to become unstable. However, the 45° trigger angle helps mitigate the instability, promoting progressive failure and ensuring stable energy absorption performance.