Papers by Keyword: Component Reliability

Abstract: Failure probability of a component is the major project of engineering probability. The reliability of a mechanical system or a structural system is calculated by components in the system. However, statistics data shows that the distribution of test data of components is not according with the distribution by theory as normal distribution. Normal distribution is extensively applied in the component reliability nowadays. Its domain is the field of real numbers, whereas, test data of exper-iments are on a finite field. Consequently, the component reliability used the normal distributions has some limitations. It is necessary to choose a suitable distribution in the calculating method. Comparing the normal distribution density curve and the statistics graph, a new distribution is pre-sented in this paper. The examples by both normal distribution and the new distribution are given, respectively. The results suggest that the new distribution is more accurate than normal distribution in the component reliability.

Abstract: Factors affecting the shape of failure rate curve are analyzed, and four elements including load, strength, degradation and lifetime index (namely, the number of load application and time) are proposed for calculating the failure rate of components. Taking the number of load application and time as the life index, respectively, the failure rate models of components consisting of four elements is developed, which can embody the effect of parameters of load, strength, degradation and life. Then, the rules that the reliability and failure rate changes as life index are studied. The result shows that the failure rate curves are partially or whole bathtub-shaped. For different parameters of load, strength and strength degradation, the curves of reliability and failure rate of components changing with time present different shapes. The models derived in this paper can calculate the failure rate of components as long as the parameters of load, strength and degradation and life index are known.