Study on inductive method for environmental measured data of random vibration

GJB/Z 126-99 «The inductive methods for environmental measured data of vibration and shock» presents a upper tolerance limits method, which is a huge improvement from the traditional envelope limits method to the statistics method, aiming at the induction of the vibration measured data. But, there are bias errors in upper tolerance factor with the specifical confidence coefficient and probability. This paper analyzes the reasons leading to the bias errors, and provides the upper tolerance factor formula with specifical confidence coefficient and probability according to the mean and standard deviations of the samples for normal distribution stochastic parameter to estimate the vibration environment condition.