Evaluation of Force-Time Changes During Impact of Hybrid Laminates Made of Titanium and Fibrous Composite

Abstract

Fibre metal laminates (FML) are the modern hybrid materials with potential wide range of applications in aerospace technology due to their excellent mechanical properties (particularly fatigue strength, resistance to impacts) and also excellent corrosion resistance. The study describes the resistance to low velocity impacts in Ti/CFRP laminates. Tested laminates were produced in autoclave process. The laminates were characterized in terms of their response to impacts in specified energy range (5J, 10J, 20J). The tests were performed in accordance with ASTM D7137 standard. The laminates were subjected to impacts by means of hemispherical impactor with diameter of 12,7 mm. The following values have been determined: impact force vs. time, maximum force and the force at which the material destruction process commences (Pi). It has been found that fibre titanium laminates are characterized by high resistance to impacts. This feature is associated with elasto-plastic properties of metal and high rigidity of epoxy -fibre composite. It has been observed that Ti/CFRP laminates are characterized by more instable force during impact in stage of stabilization of impactor-laminate system and stage of force growth that glass fibre laminates. It has been observed more stable force decrease in stage of stress relaxation and withdrawal of the impactor. In energy range under test, the laminates based on titanium with glass and carbon fibres reinforcement demonstrate similar and high resistance to low-velocity impact, measured by means of failure initiation force and impact maximum force.

Analysis of the thermal expansion coefficient of glass- and carbon-fibre-reinforced composites

“…Carbon fibres used in carbon-fibre-reinforced polymers (CFRPs) allow for a significant reduction in vehicle weight while increasing safety (Ahmad et al, 2020). The unique properties of fibre metal laminates (FMLs) (Jakubczak et al, 2016) and composites with anti-wear properties (Walczak et al, 2017) means they are increasingly used in the automotive industry.…”