本文選題：拓撲優(yōu)化　切入點：有限元　出處：《浙江大學(xué)》2017年碩士論文

【摘要】：漸進結(jié)構(gòu)優(yōu)化(ESO)方法是拓撲優(yōu)化方法中的一個重要分支,雙向漸進結(jié)構(gòu)優(yōu)化(BESO)方法在其基礎(chǔ)上,解決了單元誤刪除,結(jié)構(gòu)棋盤狀分布以及網(wǎng)格依賴性等問題。現(xiàn)存的漸進結(jié)構(gòu)優(yōu)化方法主要是基于應(yīng)力分析的,但由于工程應(yīng)用中疲勞破壞引起的結(jié)構(gòu)斷裂對安全生產(chǎn)和工程機械的使用壽命產(chǎn)生的巨大影響,因此在設(shè)計重型機械的核心部件時將疲勞壽命分析作為一個參考因素就顯得尤為重要。本文的第一部分根據(jù)單軸疲勞壽命估算方法得到結(jié)構(gòu)中各單元的疲勞壽命,然后根據(jù)疲勞壽命的大小移除那些壽命值相對較高的單元。考慮到單元誤刪除、棋盤狀分布和網(wǎng)格依賴性的影響引入過濾機制,并對過濾網(wǎng)格進行改進,考慮到各方向壽命變化的梯度影響將過濾網(wǎng)分為四個部分并進行相應(yīng)的優(yōu)化計算。第二部分通過研究分析現(xiàn)有的MATLAB結(jié)構(gòu)優(yōu)化法,開發(fā)出全新的MATLAB與ABAQUS結(jié)合的結(jié)構(gòu)優(yōu)化的系統(tǒng)。將ABAQUS作為有限元計算和建模的前處理器,根據(jù)其計算得出的各單元應(yīng)力分布情況使用MATLAB編寫疲勞壽命計算和拓撲優(yōu)化計算的相關(guān)程序。第三部分結(jié)合工程應(yīng)用的實際需求,引入多軸疲勞分析的概念。使用Wang-Brown多軸載荷循環(huán)計數(shù)法對非比例變幅載荷的加載進行循環(huán)計數(shù),隨后使用一種基于降維思想的多軸疲勞損傷模型對單元的疲勞壽命進行估算,緊接著采用線性損傷累積準則對各載荷循環(huán)的疲勞損傷進行累積。最終根據(jù)多軸疲勞分析得到的疲勞壽命進行三維結(jié)構(gòu)的拓撲優(yōu)化設(shè)計。并以推耙機中的H型架橫梁模型為工程實例進行拓撲優(yōu)化,解決了推耙機H型架橫梁在實際工作中損耗過于嚴重的問題,在使用同樣體積的材料情況下大幅提高了結(jié)構(gòu)件的使用壽命。
[Abstract]:Evolutionary structural optimization (ESO) method is an important branch of topology optimization method, bi directional evolutionary structural optimization (BESO) method on the basis of solving the unit accidentally deleted, on issues such as checkerboard and mesh structure distribution. The evolutionary structural optimization method based on stress analysis of the main if existing, but because the great influence of fatigue engineering structural damage fracture caused for the production safety and the service life of engineering machinery, so in the design with the core component of heavy machinery when the fatigue life analysis as a reference factor is particularly important. The first part of this paper according to the uniaxial fatigue life estimation method of the fatigue life obtained in each unit structure then, according to the fatigue life of the size of the removal of those values of life relatively high unit. Taking into account the unit accidentally deleted, checkerboard and mesh dependence distribution effects of lead The filtering mechanism, and the filtering mesh was improved, taking into account the effect of changes in the direction of the gradient of life and the filter screen is divided into four parts and the corresponding optimization calculation. The second part through the analysis of the existing MATLAB structure optimization method, system structure optimization of MATLAB and ABAQUS combined with new ABAQUS as. Finite element calculation and modeling of the pre processor, the unit according to the calculated stress distribution of MATLAB prepared using fatigue life calculation and topology optimization calculation procedures. In the third part, combined with the engineering application of the actual demand, the introduction of the concept of analysis of multiaxial fatigue loading. Using Wang-Brown multiaxial cycle counting method of non proportional cyclic loading cycle count, then use a multiaxial fatigue damage model based on dimension reduction method to estimate the fatigue life of the unit, followed by The linear cumulative damage criterion on the fatigue damage of the loading cycle of accumulation. Finally according to the multiaxial fatigue fatigue life analysis of the topology optimization design of 3D structure. Taking H push the rake machine in frame beam model as an example of topology optimization, solve the pushing and rake machine H frame beam in practical work the loss is too serious problems in the use of materials of the same size greatly improve the service life of the structure.

【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TB12

【參考文獻】

相關(guān)期刊論文 前1條

1 徐宜;劉云鵬;卜樹峰;;基于雨流法的機械疲勞分析[J];車輛與動力技術(shù);2008年03期

，

本文編號：1660000