摘要
傳統(tǒng)的結(jié)構(gòu)優(yōu)化設(shè)計方法不能結(jié)合各個學科的優(yōu)勢，也存在各種不確定性影響設(shè)計結(jié)果。目前柴油機連桿的優(yōu)化設(shè)計研究還主要應(yīng)用的是單學科的優(yōu)化分析技術(shù)，對柴油機連桿使用多學科設(shè)計優(yōu)化的方法進行研究的還比較少。
多學科設(shè)計優(yōu)化（Multidisciplinary Design Optimization-MDO）的設(shè)計思想和目的與現(xiàn)代柴油機設(shè)計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)計周期。因此，運用多學科設(shè)計優(yōu)化方法在柴油機及其零部件設(shè)計中的前景是很可觀的，具有重要的現(xiàn)實意義和較高的學術(shù)價值。
本文以法國熱機學會（SEMT）研發(fā)的大功率四沖程16PA6STC艦用柴油機連桿為研究對象，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)合多學科設(shè)計優(yōu)化理論對連桿進行結(jié)構(gòu)優(yōu)化，采用ISIGHT多學科設(shè)計優(yōu)化軟件集成現(xiàn)在市場上多款流行的分析設(shè)計軟件包括ANSYS、Pro/Engineer、Nastran對連桿進行約束靜力、模態(tài)條件下的結(jié)構(gòu)優(yōu)化，探索多學科設(shè)計優(yōu)化思想在柴油機零部件方面的應(yīng)用，并為連桿的進一步改進設(shè)計提供參考。

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)計的發(fā)展與現(xiàn)狀 2
1.3多學科設(shè)計優(yōu)化發(fā)展與現(xiàn)狀 3
1.4本文的主要研究內(nèi)容 5
第2章 結(jié)構(gòu)有限元及多學科設(shè)計優(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多學科優(yōu)化設(shè)計基本理論 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多學科優(yōu)化基本算法 13
2.3.1優(yōu)化問題的數(shù)學模型 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 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 65
附錄一 68