2006 Fiscal Year Final Research Report Summary

Time-space damage analysis of the short fiber reinforced thermoplastics during creep and fatigue loading

Research Project

Project/Area Number	16360335
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Research Field	Composite materials/Physical properties
Research Institution	Yamagata University
Principal Investigator	KURIYAMA Takashi Yamagata University, Venture Business Laboratory, Professor, 大学院・ベンチャービジネスラボラトリー, 教授 (10186520)
Project Period (FY)	2004 – 2006
Keywords	Fatigue / Acoustic emission / Map of acoustic velocity / Fiber brakeage / Matrix crakes
Research Abstract	The ability to effectively design and manufacture plastics for engineering applications requires a large body of knowledge on long-term performance of the materials. The fatigue life is a typical long-term property that should be characterized in components and structures where cyclic loads are experienced. There has been considerable research into the basic mechanism that cause fatigue of plastics, but still there is not a clear understanding of the mechanism in many plastics. In this study, the mechanism of the fatigue fracture of glass fiber reinforced nylon66 has been identified using acoustic emission (AE), ultrasonic measurement and optical microscopy (OM) techniques. The acoustic velocity of the edge of specimens decreased by the cyclic loading. This behavior was correlated to matrix cracks and fiber breakages at the edge of the specimens.