Reliability Analysis Approach to Fatigue Life Dispersion of Various FRP and Reliability-Based Design Safe Life

Abstract

Fatigue tests have been conducted to investigate the fatigue properties of various types of laminated composites and some statistically meaningful inference was drawn from these results. The materials used in the experiment were 4 different kinds of FRP laminates, satin woven FRP, plain woven FRP, roving woven FRP and SMC laminated FRP.Sufficient data were accumulated to produce the P-S-N diagrams for each type of laminates.A statistical approach based on the Weibull distribution was applied to the test data to evaluate the dispersion in the fatigue life of the materials. The dependences of fatigue life and its dispersion on the applied stress level, specimen size and fiber content in the specimen were discussed. The test results showed a wider experimental scatter particularly at the life range of 105 to 106 cycles than that observed on conventional metallic materials. Thus, it is emphasized that a larger reduction of design life is necessary for FRP to assure the same level of confidence and reliability as other materials. © 1979, The Society of Materials Science, Japan. All rights reserved.