船体可靠性评估

The estimation of hull reliability

为了研究不同结构船体的寿命和使用时可靠度的关系,提出了一种基于试验的可靠度估计方法。针对不同结构船体寿命服从Weibull分布,在无失效数据情形下、置信度至少为γ和寿命为t时,根据船体寿命试验数据,给出了可靠度的单侧置信下限。该方法是在Weibull分布形状参数下限已知的情况下,能将所有的无失效寿命数据进行累加,大大提高了可靠性分析的精度。最后,对钢结构、钛合金结构、铝合金结构的船体,在寿命为t月、置信度至少为γ时,计算了3种结构船体的可靠度单侧置信下限。结果表明该方法易于计算,便于工程应用。

In order to research the relation between hull life span and using reliability, a method of the hull life span estimation based on experiments was proposed. By assuming that the hull life span satisfied the Weibull distribution, with zero-failure data, confidence limits γ and life span t, the one side lower confidence limits of reliability were given according to test data of the hull life span. If the lower limits of the parameters of the Weibull distribution were known, this method can accumulate all of zero-failure data to increase the analysis presion of reliability greatly. At last, this method computes one side lower confidence limits of reliability with the hull structures as steel, titanium alloy and aluminium alloy under the hull life span t-month and the confidence γ. The results indicate that the method is easy to compute and be applied in engineering.