Application of Fracture Mechanics on Polymer Films Used for Aerospace Field(<Special Issue>M & M 2009 Conference)

The strength evaluation method of thin polymer films less than 1mm thick containing defects is not established. The purpose of this research is to establish the strength evaluation method of thin polymer films based on fracture mechanics. An initial notch was introduced at thin film specimen of Poly-Imide and Poly-Ether-Ether-Ketone. Then, specimens were stretched and the fracture stress was measured. Fracture surface of specimens were observed to analyze the fracture behavior. Stress intensity factor at fracture were measured and the trend with regard to notch length was investigated. As a result, those values were roughly constant when plastic zone at crack tip was small compared with ligament size.