2000KN單動(dòng)液壓機(jī)上橫梁結(jié)構(gòu)分析及優(yōu)化設(shè)計(jì)


摘    要

液壓機(jī)通常是利用壓力來進(jìn)行機(jī)械加工的設(shè)備，它可以廣泛應(yīng)用于各國(guó)國(guó)民經(jīng)濟(jì)各部門，并且種類有很多，發(fā)展速度也非?？欤呀?jīng)成為機(jī)械工業(yè)的一個(gè)重要的部分。液壓機(jī)是一種通用的鍛壓機(jī)械，它的主要零件的變形大小以及其它特性將直接或間接影響到工件的加工質(zhì)量。我們很多傳統(tǒng)古老的設(shè)計(jì)方法是把零件模型進(jìn)行必要的簡(jiǎn)化，大概估計(jì)一下零件的各種特性，然后將其橫梁簡(jiǎn)化成簡(jiǎn)支梁結(jié)構(gòu), 再采用材料力學(xué)的分析方法來簡(jiǎn)化計(jì)算過程，最后求得橫梁剛度和強(qiáng)度。這樣處理的后果是很難保證前面計(jì)算的精度和可靠性，而且設(shè)計(jì)計(jì)劃周期很長(zhǎng)。由于液壓機(jī)的工作狀況比較惡劣，以前在計(jì)算方法不太準(zhǔn)確的時(shí)，為了保證機(jī)器安全性，不得不采用加大安全系數(shù)的辦法來設(shè)計(jì)液壓機(jī)械，可是這樣卻使得機(jī)器結(jié)構(gòu)相當(dāng)笨重，浪費(fèi)材料不說而且無法判斷其是否滿足一些重要條件的要求，應(yīng)力分布也不盡合理。
有限單元法( FEM )則是一種為彈性力學(xué)問題提供近似解并且非?？尚蟹蠈?shí)際的重要方法， 為進(jìn)行大型復(fù)雜結(jié)構(gòu)的各種分析提供了一種強(qiáng)有力并且精確的分析手段，在液壓機(jī)的整體以及主要零部件的設(shè)計(jì)中已經(jīng)成為了必不可少的重要工具。
本文參考液壓機(jī)的設(shè)計(jì)理論，結(jié)合原有液壓機(jī)結(jié)構(gòu)設(shè)計(jì)方案和前人設(shè)計(jì)成果經(jīng)驗(yàn)，介紹了一些傳統(tǒng)設(shè)計(jì)方法的弊端，并以大型計(jì)算機(jī)有限元（FEM）軟件ANSYS作為工具，首先對(duì)該單動(dòng)液壓機(jī)上橫梁整體結(jié)構(gòu)進(jìn)行幾何建模，然后進(jìn)行網(wǎng)格劃分并施加約束和載荷，再進(jìn)行有限元分析和計(jì)算，了解其整體結(jié)構(gòu)的受力特點(diǎn)和關(guān)鍵部件部位的應(yīng)力應(yīng)變狀態(tài)，然后分別對(duì)該液壓機(jī)的上橫梁各個(gè)結(jié)構(gòu)的尺寸進(jìn)行了參數(shù)化設(shè)計(jì)并編程，在應(yīng)力許可范圍內(nèi)，利用優(yōu)化器及傳統(tǒng)優(yōu)化的方法以其重量為目標(biāo)函數(shù)進(jìn)行優(yōu)化設(shè)計(jì)。最終液壓機(jī)上橫梁結(jié)構(gòu)在應(yīng)力增加不大的情況下，整體的質(zhì)量得以大大減輕。

關(guān)鍵詞：液壓機(jī) 有限元 結(jié)構(gòu)設(shè)計(jì) 優(yōu)化 ANSYS

ABSTRACT

Hydraulic pressure is one of the processing equipment, it is broadly used in the national economy departments, and developed rapidly. It has become an important component in a machine tool industry . The major deformation of parts and other properties will directly or indirectly affect the processing quality. The traditional design method  is to simplify the parts model, and roughly estimate the properties of parts. The beam will be reduced to simply supported beam, then material mechanics will be used to simplify calculation for beam stiffness and strength. It is difficult to ensure the accuracy and reliability of the calculation and design cycle is long. Because of the hydraulic press is under poor working conditions,  in the circumstances of not accurate calculation, in order to ensure the safety, people often  increase security coefficient to design hydraulic machinery, which makes the machine structure bulky, waste materials and can't decide whether it meet important characteristic request, and the stress distribution is not reasonable.
Finite element method (FEM) is an important method for elastic mechanics to provides a feasible and the approximate solutions.It provides a powerful and precise analysis means for large and complex structure of.In the design of the whole hydraulic press  and the main components and it has become an indispensable tool.
Based on the hydraulic press design theory, refering to the original structure design and former hydraulic design results experience, this paper uses a finite element software ANSYS analysis tools for the type hydraulic press beam in the whole structure finite element analysis and calculation. So we can the understand the mechanical characteristics and the stress state of the whole structure. And then to parameterly design beam the beam structure. Within the scope of license of stress, we can do optimization design with its weight as the objective function. Eventually with the beam's stress of not increase, the overall quality is to reduce.

Key words：Hydraulic pressure，F(xiàn)EM method，Structural analysis，
Structural optimization design， ANSYS

目   錄

中文摘要 Ⅰ
ABSTRACT Ⅱ
1緒論 1
  1.1 液壓機(jī)結(jié)構(gòu)設(shè)計(jì)及優(yōu)化的重要性 1
  1.2 液壓機(jī)設(shè)計(jì)方法的發(fā)展?fàn)顩r 1
   1.2.1傳統(tǒng)方法及不足 2
   1.2.2現(xiàn)代設(shè)計(jì)方法的出現(xiàn)及研究現(xiàn)狀 2
    ①有限元及優(yōu)化方法的出現(xiàn) 2
    ②計(jì)算機(jī)的發(fā)展和有限元分析軟件（ANSYS）的出現(xiàn) 2
    ③新的優(yōu)化算法及基于APDL參數(shù)化的有限元分析方法 3
  1.3 發(fā)展趨勢(shì) .5
  1.4 課題研究?jī)?nèi)容及主要任務(wù) 5
  1.5 課題意義及目前研究的不足 5
 2液壓機(jī)上橫梁建模、網(wǎng)格劃分、施加約束及載荷 7
   2.1 模型的基本假設(shè) 7
   2.2 分析方案的制定 7
   2.3 建模方法的選擇 8
   2.4 建立幾何模型 9
   2.5 網(wǎng)格劃分 16
   2.6施加約束及載荷 17
   2.7求解 18
 3液壓機(jī)上橫梁的靜態(tài)有限元分析 19
   3.1 對(duì)模型進(jìn)行有限元分析 19
   3.2 對(duì)計(jì)算結(jié)果的分析 19
   3.2.1應(yīng)力計(jì)算結(jié)果分析 19
   3.2.2位移計(jì)算結(jié)果分析 22
  3.3 分析總結(jié) 24
 4液壓機(jī)上橫梁的優(yōu)化分析 25
  4.1 優(yōu)化方法的選擇 25
  4.2 優(yōu)化分析的數(shù)學(xué)模型 26
  4.3 優(yōu)化分析的步驟 27
  4.4 優(yōu)化過程 28
   4.4.1對(duì)設(shè)計(jì)變量D1的優(yōu)化 29
   4.4.2對(duì)設(shè)計(jì)變量D2的優(yōu)化 33
   4.4.3對(duì)設(shè)計(jì)變量D3的優(yōu)化 35
   4.4.4對(duì)設(shè)計(jì)變量D4的優(yōu)化 37
   4.4.5對(duì)設(shè)計(jì)變量H2的優(yōu)化 39
   4.4.6對(duì)設(shè)計(jì)變量R3的優(yōu)化 42
   4.4.7對(duì)所有設(shè)計(jì)變量進(jìn)行整體優(yōu)化 44
   4.4.8優(yōu)化總結(jié) 49
5總結(jié) 50
參考文獻(xiàn) 51
附錄A：參數(shù)化模型命令流 53