摘要
傳統(tǒng)的結(jié)構(gòu)優(yōu)化設(shè)計(jì)方法不能結(jié)合各個(gè)學(xué)科的優(yōu)勢(shì)，也存在各種不確定性影響設(shè)計(jì)結(jié)果。目前柴油機(jī)連桿的優(yōu)化設(shè)計(jì)研究還主要應(yīng)用的是單學(xué)科的優(yōu)化分析技術(shù)，對(duì)柴油機(jī)連桿使用多學(xué)科設(shè)計(jì)優(yōu)化的方法進(jìn)行研究的還比較少。
多學(xué)科設(shè)計(jì)優(yōu)化（Multidisciplinary Design Optimization-MDO）的設(shè)計(jì)思想和目的與現(xiàn)代柴油機(jī)設(shè)計(jì)的要求是完全吻合的，它可以提高產(chǎn)品質(zhì)量、降低成本、縮短設(shè)計(jì)周期。因此，運(yùn)用多學(xué)科設(shè)計(jì)優(yōu)化方法在柴油機(jī)及其零部件設(shè)計(jì)中的前景是很可觀的，具有重要的現(xiàn)實(shí)意義和較高的學(xué)術(shù)價(jià)值。
本文以法國(guó)熱機(jī)學(xué)會(huì)（SEMT）研發(fā)的大功率四沖程16PA6STC艦用柴油機(jī)連桿為研究對(duì)象，利用結(jié)構(gòu)線性有限元理論分析連桿在最大壓縮工況和最大拉伸工況下連桿的受力狀態(tài)，并在此基礎(chǔ)上結(jié)合多學(xué)科設(shè)計(jì)優(yōu)化理論對(duì)連桿進(jìn)行結(jié)構(gòu)優(yōu)化，采用ISIGHT多學(xué)科設(shè)計(jì)優(yōu)化軟件集成現(xiàn)在市場(chǎng)上多款流行的分析設(shè)計(jì)軟件包括ANSYS、Pro/Engineer、Nastran對(duì)連桿進(jìn)行約束靜力、模態(tài)條件下的結(jié)構(gòu)優(yōu)化，探索多學(xué)科設(shè)計(jì)優(yōu)化思想在柴油機(jī)零部件方面的應(yīng)用，并為連桿的進(jìn)一步改進(jìn)設(shè)計(jì)提供參考。

關(guān)鍵詞 連桿；MDO；ISIGHT

Abstract
Traditional structural optimization method can not combine the prepotent parts of every subject, and also have some uncertainties which can affect the design results. It’s the signle subject optimization analytical technology are mainly used in the the existing situation of the optimization design reaserch of the diesel engine connecting rod, and the Multidisciplinary Design Optimization-MDO is relatively shortly in used.
The thought and purpose of the MDO is completely consistent with the request of the modern diesel engine design, which could improve the quality of the products、lower the cost、reduce the design cycle-time. Therefore, there is a impressive prospect of using the MDO method in the design work of the diesel engine and other relative components, and also which holds a important practical significance and high academic value.
In this thesis, the connecting rod of the 16PA6STC diesel engine which is developed by the SEMT is taken to the object of study, the structural linear finite element theory is used in the analysis of the stress in the most compressive and the most stretching working situation, and on the basis of this combined with the MDO theory to operate a structural optimization to the connecting rod. The MDO software ISIGHT is used to integrate three extensively used engineer design softwares, including Pro/Engineer、ANSYS、Nastran, to complete the structural optimization work on the condition of restrain the stress and modal of the connecting rod, explore the application of the MDO design method in the diesel engine field, offer a reference for the further improvement design study.

Key words connecting rod; MDO; ISIGHT










目 錄
摘要 I
Abstract II
第1章 緒論 1
1.1選題的目的和意義 1
1.2連桿有限元分析及優(yōu)化設(shè)計(jì)的發(fā)展與現(xiàn)狀 2
1.3多學(xué)科設(shè)計(jì)優(yōu)化發(fā)展與現(xiàn)狀 3
1.4本文的主要研究?jī)?nèi)容 5
第2章 結(jié)構(gòu)有限元及多學(xué)科設(shè)計(jì)優(yōu)化基本理論 7
2.1結(jié)構(gòu)有限元法的基本理論與基本算法 7
2.1.1結(jié)構(gòu)有限元基本理論 7
2.1.2結(jié)構(gòu)有限元基本算法 8
2.2多學(xué)科優(yōu)化設(shè)計(jì)基本理論 11
2.2.1系統(tǒng)建模 11
2.2.2系統(tǒng)分類 12
2.2.3優(yōu)化策略 12
2.2.4耦合變量的處理 13
2.3多學(xué)科優(yōu)化基本算法 13
2.3.1優(yōu)化問題的數(shù)學(xué)模型 13
2.3.2模型多元函數(shù)分析 14
2.3.3優(yōu)化條件 16
2.3.4 NLPQL優(yōu)化算法概述 16
2.3.5 NLPQL搜索策略 17
2.4本章小結(jié) 18
第3章 連桿的有限元分析 19
3.1有限元網(wǎng)格的劃分 20
3.2邊界條件和載荷的施加 20
3.2.1接觸的施加 21
3.2.2 螺栓預(yù)緊力的施加 21
3.2.3 襯套、軸瓦預(yù)緊力的施加 22
3.2.4 載荷的施加 23
3.3連桿的強(qiáng)度分析 25
3.3.1 最大壓縮工況 25
3.3.2 最大拉伸工況 28
3.4連桿的靜疲勞強(qiáng)度分析 30
3.4.1 疲勞理論概述 30
3.4.2 連桿靜態(tài)疲勞分析 31
3.5連桿的模態(tài)分析 31
3.5.1 頻率分析 31
3.5.2 振型分析 32
3.6本章小結(jié) 35
第4章 ISIGHT單學(xué)科集成技術(shù)的研究 37
4.1 集成軟件Pro/Engineer 37
4.1.1模型及參數(shù)關(guān)系文件準(zhǔn)備 38
4.1.2錄制Pro/Engineer的trail.txt文件 39
4.1.3命令行調(diào)試以及ISIGHT-FD集成 39
4.2集成軟件Nastran 41
4.2.1分析及求解過程 42
4.2.2 Nastran輸入輸出文件的制作 43
4.3集成軟件ANSYS 44
4.4本章小結(jié) 46
第5章 連桿的集成優(yōu)化設(shè)計(jì) 47
5.1優(yōu)化參數(shù)的選擇 49
5.2集成流程 50
5.2.1集成Pro/Engineer 50
5.2.2集成ANSYS 54
5.2.3集成nastran 56
5.2.4優(yōu)化參數(shù)定義 59
5.2.5優(yōu)化結(jié)果 61
5.3本章小結(jié) 62
總結(jié)及展望 63
總結(jié) 63
展望 63
參考文獻(xiàn) 65
附錄一 68