Evaluation of Weibull Modulus by Weibull Plane

A Weibull space is defined by three coordinates of failure probability, effective volume and strength. The two-parameter Weibull distribution function is presented by a plane (Weibull plane) in the Weibull space. The Weibull modulus can be obtained from the gradient of the Weibull plane. Therefore, the Weibull modulus can be evaluated by the method of least squares from the strength data obtained by various tests of different effective volume specimens. The Weibull modulus estimated by this method is more accurate than that by the conventional Weibull plot method. The Weibull modulus estimated by this method is expected to be twice as accurate as that by the conventional method, particularly when the strength data are obtained from two different volumes whose ratio is more than 100.