海水环境下某封闭壳体的疲劳寿命研究

发布时间：2018-08-08 12:34

【摘要】：随着科技的进步与社会的发展,人们对能源的要求也日益增高,在不断增长的生存压力下各国对海洋能源的开发越来越重视。在科技发展迅速的今天,要想保障国家陆海领土的完整性以及能源的开采需求,深水设备的开发也就变得很有必要。本文以某封闭式箱形壳体件的疲劳寿命评估为研究对象,利用有限元软件ANSYS计算出箱形壳体零件的疲劳寿命为目标。首先对箱形壳体零件的工作环境进行了一个深入的研究并计算出了海流力及波浪力,之后又对评估零件疲劳寿命的理论及影响因素进行了一个广泛的研究,以便取恰当的疲劳寿命准则。然后利用ANSYS的APDL设计语言对箱形壳体零件的焊接部位进行了细致的建模,并分析计算出了箱形壳体件的焊接残余应力值,为下一步探究焊接残余应力对疲劳寿命的影响提供一个计算依据,并且由已知的受力分析条件对箱形壳体件进行了静强度分析、模态分析以及疲劳寿命评估。最后给出了箱形壳体件的仿真疲劳寿命值,并在文章最后对海水的腐蚀机理进行了一个初步的研究。最终得到如下仿真结果:(1)壳体焊接部位处的残余应力值约1800pa。(2)壳体的前六阶固有频率值均为零,第七、八、九阶固有频率值分别为9291、12278、12514。(3)壳体的疲劳寿命约为8.9年。
[Abstract]:With the progress of science and technology and the development of society, the demand for energy is also increasing. Under the increasing pressure of survival, countries pay more and more attention to the development of marine energy. With the rapid development of science and technology, it is necessary to develop deep water equipment in order to ensure the integrity of land, sea and territory and the energy demand. This paper takes the fatigue life evaluation of a closed box shell as the research object and calculates the fatigue life of the box shell parts by using the finite element software ANSYS. First of all, the working environment of box shell parts is studied deeply, and the current force and wave force are calculated. Then, the theory of evaluating the fatigue life of the parts and the influencing factors are studied extensively. In order to obtain the appropriate fatigue life criteria. Then the welding position of box-shell parts is modeled by APDL language of ANSYS, and the welding residual stress of box-shell parts is analyzed and calculated. It provides a basis for further study on the influence of welding residual stress on fatigue life, and the static strength analysis, modal analysis and fatigue life evaluation of the box shell are carried out from the known stress analysis conditions. Finally, the simulated fatigue life of the box shell is given, and a preliminary study on the corrosion mechanism of seawater is carried out at the end of the paper. The simulation results are as follows: (1) the residual stress at the welding position of the shell is about 1800pa. (2) the first six natural frequencies of the shell are all zero, and the seventh, eighth and ninth natural frequencies are respectively 9291C 12278U 1251414. (3) the fatigue life of the shell is about 8.9 years.
【学位授予单位】：沈阳理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P742

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