大深度载人潜水器圆柱形耐压壳体可靠性研究

Research on Reliability of Cylindrical Pressure Shell of Large-depth HOV

大深度载人潜水器上的圆柱形耐压壳体包含多个失效模式,各失效模式之间存在着共同变量和参数,在可靠性分析时需考虑各失效模式的相关性。论文开展了圆柱形耐压壳体多失效模式之间相关度分析方法的研究,形成准确的可靠度评估方法,采用灵敏度方法得到各参数的均值和标准差对结构可靠性的影响程度。以圆柱形耐压壳体结构的计算机罐为例进行分析,发现采用CCS规范开展设计时,计算机罐的可靠度为99.99986%(可靠度指标为4.6894),满足规范建议值的要求。采用灵敏度分析方法分析得到影响计算机罐可靠度的最主要因素为球形封头,在目前设计规范下适当增加封头厚度,同时在加工过程中控制封头加工偏差可有效降低失效概率。

Large-depth human-occupied vehicle(HOV)includes several pressure-resistant cylindrical structures,and their reliability analysis is important to the safety of the HOV.There are multiple failure modes for the cylindrical pressure shell,and there are common variable parameters among these failure modes,correlation between failure modes should be considered in reliability analysis.This paper researches the correlation analysis method between multiple failure modes of the cylindrical pressure shell and forms an accurate method of reliability evaluation.The sensitivity method is applied to obtain the influence of the mean value and standard deviation of each factor on structural reliability.Taking the cylindrical pressure shell of the computer tank as an example for analysis,when the CCS specification is adopted to the design,the reliability of the computer tank is 99.99986%(the reliability index is 4.6894),which meets the requirements of relevant recommendations.It is found from sensitivity analysis that the most important factor affecting the reliability of the cylindrical is the spherical head.Under current design specifications,appropriately increasing the thickness of the head and controlling deviation of the thickness in processing can effectively reduce the failure probability of the cylindrical pressure shell.