大深度载人潜水器载人耐压球壳的疲劳载荷谱分析

Determination of fatigue load spectrum for pressure hull of a deep manned submersible

大深度载人潜水器的载人耐压球壳是载人潜水器上的最关键部件,它不仅为载人潜水器驾驶员和科学家提供了深海作业的生存空间,而且也为众多的非耐压仪器设备提供了工作环境。载人潜水器每执行一次下潜任务,耐压球壳都要承受一次海水压力作用,随着使用次数的增加。有可能会发生载人耐压球壳的低周疲劳破坏。为了确保载人潜水器载人球壳的安全性,在设计阶段必须进行载人耐压球壳的低周疲劳寿命分析。作为载人球壳低周疲劳寿命分析的基础,必须首先确定载人耐压球壳的疲劳载荷谱。本文通过对美国Alvin深海载人潜水器的使用统计资料的深入分析,提出了可以用GUMBEL分布来描述大深度载人耐压球壳疲劳载荷谱。根据设计任务书中规定的总的下潜次数要求,最后给出了我国目前正在研制的7000米载人潜水器耐压球壳的疲劳载荷谱。

The pressure hull for carrying pilots and scientists is the most critical component in a deep manned submersible. It does not only provide the living space for the pilots and scientists but also provide the working conditions for many non-pressure-resisting equipments. For the manned submersible, the pressure hull will be subjected to a cyclic load for every diving task. As the number of diving increases, the pressure hull may be resulted in a low cycle fatigue failure. In order to guarantee the safety of the pressure hull, it is necessary to carry out a low cycle fatigue analysis for the pressure hull in the design. In order to do this it is prerequisite to determine the fatigue load spectrum. In this paper a detailed analysis was carried out for the diving statistics of Alvin submersible. Based on this analysis, it is proposed that the probability distribution for the fatigue load spectrum of deep manned submersibles can be described as Gumbel distribution. According to the requirement of the total diving number and the assumption of the distribution type, the fatigue load spectrum for the 7000 m deep manned submersible is given.