Decreasing the number of test specimens by utilizing both fracture stress and fracture location for the estimation of Weibull parameter

In a bending load test for brittle materials, such as ceramics for spacecraft and aircraft, decreasing the number of test specimens required is a crucial problem. This paper discusses the effectiveness of using the information of both fracture stress and fracture location to decrease the number of specimens required to obtain the same precision as the Weibull estimator. The following results were obtained: It was found that by adding the fracture location information, the precision of the Weibull parameter estimation under the optimal design became 1.5-1.9 times better compared with the case of using only the fracture stresses. This means the number of samples necessary to attain the same precision becomes 1/1.5-1/1.9. Tables and figures which give information on the number of samples necessary to attain the required precision are given. (C) 2004 Kluwer Academic Publishers.