Burst strength of composite cylinders - Assessment of the type of statistical distribution

AbstractComposite materials show an extraordinary change of properties depending on service life. This implies the necessity to find tailored methods to determine strength and residual strength of composite cylinders. This determination can be done by load cycle tests [1] or, in some cases, primarily by slow burst tests [2]. The results of both test methods need statistical assessment for the precise description of strength. Especially the statistical assessment of burst related strength properties has a high uncertainty. Sample size [3] and scatter distribution were identified as major influences on uncertainty. It is unclear if a Gaussian normal distribution, a Weibull distribution or others describe the scatter behaviour correctly. An assumption has to be found and confirmed to prevent overestimation of survival rate, respectively reliability, in the interval of one failure per 104 to 108 cylinders.