Abstract
In the aerospace industry, composites are used extensively due to the specific strength and specific modulus of composite materials. Because of the recent development of reusable spacecrafts, such as Space X’s Falcon 9 and the Sierra Nevada Corporation’s (SNC) Dream Chaser, a high cycle fatigue analysis of the materials used on these spacecrafts was conducted. The materials investigated are unidirectional carbon fiber and bismaleimide resin (BMI) composite. Experiments were performed with a testing frequency of 8Hz., using an Instron 8872 fatigue testing system. Tensile coupons were tested at intermediate intervals in the ranges from 98 to 68 percent of ultimate strength. Stress and Number of cycles curves (S-N) were generated in order to show the fatigue life of the carbon fiber reinforced polymer (CFRP). The results did not show expected trends due to the inconsistency of the results. Further investigation showed that voids and defects resulting from sample manufacturing process may have caused the inconsistent fatigue test results.