抄録
Polymer films are expected to be feasible candidates for the liner of cryogenic composite tank structures. This study investigates the damage behaviors of polymer-lined CFRP laminates under tensile loading at room and cryogenic temperatures. Because matrix cracks in CFRP laminates are considered to be more susceptible to formation than polymer film fracture, damage behaviors of polymer films beyond the onset of matrix cracks in layers adjacent to polymer film are the major concerns herein. Specimens consisting of polymer films and cross-ply laminates were prepared by co-curing and subjected to tension load. Penetration of matrix cracks in composite layers into polymer films was observed in the case of thermoplastic polyimide-lined CFRP laminates, while crack deflection into interfaces between CFRP and polymer films was observed in the case of liquid crystalline polymer and polyimide films. Finally, mechanical properties of polymer films and adhesive properties between CFRP and polymer films were measured in order to discuss the crack penetration/deflection behaviors in polymer-lined CFRP laminates. An energetic criterion on crack penetration/deflection including the effects of residual thermal stress was applied to the present experimental results, and suitable polymer characteristics were clarified.
