Tensile behavior of aluminum-CFRP hybrid composites at intermediate strain rates

Abstract

Aluminum alloy is widely used in the field of airplanes and automobiles since it is superior to reliability, economical and light weight. However, aluminum alloy has a limitation in the feature of specific strength, corrosion and fatigue resistance. The usage of fiber reinforced composites is increasing gradually in order to overcome these problems. Carbon fiber reinforced polymer, CFRP which is commonly used has better specific strength, specific stiffness, fatigue resistance, corrosion resistance and impact energy absorption ability than metal materials. However, there are limits in the usage since it is weak in heat and it has a risk in impact damage because of its brittleness. To solve these problems of aluminum alloys and fiber reinforced composites, the usage of hybrid composites which is combined with two different kinds of material is now increasing. Hybrid composites has excellent fatigue resistance, high yield stress, high tensile strength and it has relatively larger failure strain than fiber reinforced composites. Many studies have been conducted in order to apply it to structural materials of airplane. Recently the interest in eco-friendly & high efficiency automobile is increasing. Therefore, many studies are going on in order to make automobile light weight and improve fuel efficiency and performance by using hybrid composites. Studies on the fracture characteristic of hybrid composites used in the aerospace field were focused on the range of strain rates more than 100/s. On the other hand, intermediate strain rate under 100/s in automobile which occurs when vehicle crashes is dominant but the studies on this subject is insufficient so far. In this study, specimens were fabricated by using hybrid composites in the form of CFRP/Aluminum/CFRP by changing the stacking sequence. Tensile properties were measured at strain rates between 0.001/s and 100/s and properties of the hybrid specimen were compared to the results of the aluminum alloy and CFRP ...