【作者】 刘晨；

【导师】 沈珉；

【作者基本信息】 天津大学 ， 固体力学， 2010， 硕士

【摘要】 随着经济全球化和制造业的迅猛发展,大型结构物或组装部件经常在洲际间跨大洋进行长时间的海上运输,为了能够保证结构或部件运输的稳定和安全,其海运工装夹具在规定的可靠性要求下达到技术性能指标、制造成本和使用寿命最优,有必要运用先进的分析手段,借助计算机仿真技术,对海运工装夹具进行可靠性分析和验证。本文通过广泛调研,以某大型飞机部件运输工装夹具为模型,建立了模拟海运工况下的有限元模型,并对工装夹具不同部件的连接采用接触有限元进行了模拟,分析了不同船型条件下夹具结构的强度。根据结构可靠性理论和概率有限元方法,编制了该海运工装夹具结构的概率有限元分析文件,使用响应面法(RES)和蒙特卡罗模拟法(MC)计算分析其结构的可靠性,得到相关参数信息。本文意在探索针对海运工装夹具结构强度进行概率设计和可靠性分析的方法,以便为大型飞机部件海运工装夹具强度设计提供参考和改进建议。本文主要内容:1介绍了结构可靠性的基本理论和分析方法以及有限元软件中使用的可靠性分析的方法和原理。2建立了某大型飞机后机身海运工装夹具有限元模型,模拟海运工况条件下进行了针对不同船型的确定性强度分析,并对其设计提出改进建议。3采用参数化建模方法,建立了大型飞机后机身海运工装夹具的概率有限元模型;编制适用于可靠性分析的概率分析文件;根据大飞机海运工装夹具设计规范中的极限载荷,计算工装夹具结构(在一定概率下)的可靠性参数信息,包括失效概率、可靠度、可靠性安全系数、灵敏度等。4采用响应面法对上述海运工装夹具进行了可靠性分析,并用蒙特卡罗模拟法进行了验证,分析误差。结果表明:采用响应面法对大型复杂海运工装夹具结构进行可靠性分析具有较好的精度,且有计算量小、耗时少等优点。本文以某大型飞机部件海运工装夹具为例,对强度进行了确定性分析和可靠性分析,采用传统的许用应力法和符合实际的概率强度分析法,针对海运工况,得出该结构强度是安全和可靠的结论。探索了对大型复杂结构或装配结构进行整体可靠性分析的方法,通过比较响应面法和蒙特卡罗模拟法的分析数据结果,表明采用响应面法来分析海运工装夹具等复杂结构是可行的。更多还原

【Abstract】 With economic globalization and the rapid development of manufacturing, large structures or components have been transported between continents or oceans. In order to ensure the stability and security of the structures or components during the transportation and their clamping fixture to have the best optimization of technology performance, manufacturing costs and optimum service life under the reliability requirements, it is necessary to apply advanced analytical tools, the use of computer simulation technology to do the reliability of structures analysis and verification. After extensive research, a large clamping fixture model of aircraft has been set up to simulate the marine operating conditions and the model with the contact processed has been simulated and analyzed the strength under different strength conditions. Then based on probabilistic finite element and structural reliability theory, the probability analysis document is written for further analysis. The response method and Monte Carlo simulation method are used to do the reliability analysis. Many relevant parameters are obtained to summarize the general process of structural reliability design and analysis. The results can provide reference for the project and some suggestions for improvement. Main contents:1 The basic theory of structural reliability analysis methods and finite element software used in the reliability of the methods and principles have been introduced2 Back fuselage finite element model of clamping fixture is established. Certainty strength analysis is finished under the simulation marine conditions on different ship types and some improvements are recommended.3 Parametric modeling method is used to set up the probabilistic finite element model. Then the probability document for the reliability analysis is written. The structure is calculated under the limit load from design specification (some probability) and the parameter information, including the failure probability, reliability, reliable safety factor, sensitivity etc. ,are achieved.4 Response method and Monte Carlo method are compared and analytical error is analyzed. It is obtained that response methodology for complex reliability analysis of marine structure has good precision , less computation times and time-saving advantages . This article takes a large aircraft components clamping fixture as an example to finish certainty strength analysis and reliability analysis, uses the traditional allowable stress method and realistic probability analysis method to get the conclusions that the structure is safe and reliable. The way to solve the reliability problem of complicated structure is explored by comparing the response surface method and Monte Carlo simulation data results. Response surface method will be used widely between more complex structures because of the advantage and it is feasible.更多还原