Affiliation:
1. Department of Mechanical Engineering, University of Delaware, Newark, DE 19716
2. Department of Mechanical Engineering, Louisiana State University, Baton Rouge, LA 70803
Abstract
Excellent mechanical properties such as high-strength, low weight, fatigue life, and impact resistance, as well as advanced manufacturing methods and flexibility of the stacking sequence make polymer matrix composites attractive candidates for use in several performance-oriented structures. However, relatively little is known of their response to impact loading, which usually occurs at strain rates higher than those used to measure the quasi-static mechanical properties of materials. In this study, the split-Hopkinson bar is used extensively to study the effect of fiber orientation on the compressive dynamic properties of a unidirectional IM7/8551-7 graphite/epoxy composite. The specimens were approximately 3/8. cubes, and were prepared using a water-cooled diamond grit blade. The off-axis angles were 0 (longitudinal direction), 15, 30, 45, 60, 75, and 90 (transverse direction) degrees. Quasi-static tests were also performed for comparison purposes. The high strain rates vary from 250-1100/s. The tests show that changing the fiber orientation changes the values of the ultimate strength and strain of the IM7/8551-7 graphite/epoxy composite. The results show that the ultimate strength in general decreases as the off-axis (test) angle is increased. However, the results show that the decrease is not uniform as in the case of the quasi-static tests. The strain increases for initial increase in the off-axis angle, but then the results don’t show any consistent trend for additional angle increments. A semi-empirical equation is obtained for this material system and can be modified to account for other polymer matrix composites.
Subject
Materials Chemistry,Mechanical Engineering,Mechanics of Materials,Ceramics and Composites
Cited by
38 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献