Abstract
Thin polyimide (PI) films have been widely used for spacecraft polymeric materials. However, small defects often initiate at the surface of PI films by the erosion caused by atomic oxygen present in space environment, and decreases mechanical strength significantly. Our previous experiments determined fracture toughness J_<IC> of PI films in the direction of film thickness considering the crack propagation from a surface short crack. In this paper, tensile tests were carried out using the same PI films used in our previous report, and CTOD values were measured by 3D laser scanning microscope to confirm the validity of J_<IC>. Fracture toughness tests were carried out with two types of specimens with different pre-crack lengths, 20μm and 40μm. As a result, CTOD_<IC> values of 20μm and 40μm pre-cracked specimens were determined to be 4.43μm and 6.08μm, respectively. It was found that CTOD was proportional to J, which corresponded well with generally accepted relationship between these two parameters. Therefore, J_<IC> values obtained in our previous work are valid as fracture toughness of PI films when crack propagates in the direction of film thickness.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: The Proceedings of Mechanical Engineering Congress, Japan
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
