本文選題：輕量化研究 + 不確定性誤差��； 參考：《上海海洋大學(xué)》2017年碩士論文

【摘要】：在產(chǎn)品輕量化研究中可以使用輕質(zhì)材料,但是其成本往往很高,在滿足一定強(qiáng)度和剛度下,提高設(shè)計(jì)質(zhì)量從而達(dá)到輕量化設(shè)計(jì),為前期設(shè)計(jì)減少成本。針對(duì)數(shù)學(xué)非線性回歸問題,不斷改進(jìn)設(shè)計(jì)模型和設(shè)計(jì)參數(shù),本文主要的目標(biāo)是對(duì)比前人的算例來體現(xiàn)響應(yīng)面優(yōu)化方法的優(yōu)越性:全局搜索、迭代次數(shù)少、能減少更多體積或重量。用函數(shù)關(guān)系擬合實(shí)際的仿真模型,采用篩選試驗(yàn)來確定優(yōu)化方向,主要的工作是找到最佳領(lǐng)域并得到最優(yōu)解,響應(yīng)面法的精髓是在于減少試驗(yàn)的基礎(chǔ)上獲得更精確地?cái)M合目標(biāo)值,降低不確定性誤差ε值,盡量平衡試驗(yàn)次數(shù)和效果,以達(dá)到高效率平衡點(diǎn),從而使設(shè)計(jì)效果最佳。RSM是一種序貫方法,先析因分析,確定是一階線性回歸模型還是二階曲面模型,如果方差分析中所有P值都小于0.05則為二階模型,再調(diào)中心點(diǎn)和水平范圍尋優(yōu)。RSM的擬合方程不外乎是一階模型或者二階方程。一階模型采用最小二乘法可以快速定位最優(yōu)解;二階模型先找到最佳鄰域然后在最佳領(lǐng)域內(nèi)求最優(yōu)解,其中最佳鄰域的判定條件是實(shí)際約束S與擬合約束均值β_0相對(duì)誤差小于5%,最優(yōu)解的條件是擬合約束小于實(shí)際約束且體積最小。研究的對(duì)象是桁架桿、曲柄和三角臂,利用計(jì)算機(jī)CAD和CAE技術(shù)編寫ANSYS的APDL程序內(nèi)嵌應(yīng)力并能得到各應(yīng)力和體積,利用Soildworks建模分析,采用優(yōu)化軟件Minitab和Design-expert進(jìn)行集成優(yōu)化,必須要求試驗(yàn)者有工程基礎(chǔ)知識(shí)和經(jīng)驗(yàn),最終才能解決和優(yōu)化工程實(shí)際結(jié)構(gòu)問題,通過響應(yīng)面法的反饋調(diào)整,在確定的全局內(nèi),人為設(shè)置中心點(diǎn)和搜索水平范圍,從而提高尋優(yōu)效率。在桁架桿實(shí)例中要做的是進(jìn)行協(xié)同優(yōu)化,即考慮形狀變化和尺寸變化下同時(shí)進(jìn)行兩者的優(yōu)化,難點(diǎn)在于形狀變化和尺寸變化的相互耦合性,采用響應(yīng)面法不僅無需Lagrange乘子,而且能避開形狀變化和尺寸變化間的相互耦合,通過調(diào)整試驗(yàn)中心點(diǎn)和搜索水平范圍,以響應(yīng)面為指向進(jìn)行優(yōu)化。在優(yōu)化過程中發(fā)現(xiàn)桁架桿5桿有耦合性,表現(xiàn)形式為應(yīng)力集中,為此應(yīng)提高A5截面積大小,這些都是實(shí)驗(yàn)者人工調(diào)控的,根據(jù)響應(yīng)面法的反饋指向人工調(diào)整設(shè)計(jì)域,這也是響應(yīng)面法高效的來源,只需迭代三次就能找到形狀最優(yōu)點(diǎn),迭代兩次能找到尺寸最優(yōu)點(diǎn),最后迭代一次能找到協(xié)同優(yōu)化設(shè)計(jì)最優(yōu)解。在連桿和三角臂算例中為方便計(jì)算采用Soildworks建模并用其自帶算法優(yōu)化,但是優(yōu)化精度不高,所以用響應(yīng)面法進(jìn)行二次優(yōu)化,在最佳領(lǐng)域內(nèi)找最優(yōu)解。
[Abstract]:Lightweight materials can be used in product lightweight research, but their costs are often very high. Under certain strength and rigidity, the design quality can be improved to achieve lightweight design, which can reduce the cost for early design. In view of the mathematical nonlinear regression problem, the design model and design parameters are continuously improved. The main goal of this paper is to show the superiority of the response surface optimization method by comparing with the previous examples: global search, fewer iterations, Can reduce more volume or weight. The function relation is used to fit the actual simulation model and the selection experiment is used to determine the optimization direction. The main work is to find the best field and get the optimal solution. The essence of response surface method is to obtain more accurate fitting target value, reduce uncertainty error 蔚 value, and balance test times and effect as far as possible, so as to achieve high efficiency balance point. RSM is a sequential method to optimize the design effect. First, factor analysis is used to determine whether it is a first-order linear regression model or a second-order surface model, and if all P values in ANOVA are less than 0.05, it is a second-order model. The fitting equation of RSM is either a first order model or a second order equation. The first order model uses the least square method to locate the optimal solution quickly, and the second order model first finds the best neighborhood and then finds the optimal solution in the best domain. The optimal neighborhood condition is that the relative error between the actual constraint S and the fitting constraint mean 尾 0 is less than 5 and the optimal solution condition is that the fitting constraint is less than the actual constraint and the volume is the smallest. The object of this study is truss bar, crank and triangle arm. The embedded stress in APDL program of ANSYS is compiled by computer CAD and CAE technology, and each stress and volume can be obtained. Soildworks modeling and analysis are used, and the optimization software Minitab and Design-expert are used for integrated optimization. The basic engineering knowledge and experience must be required in order to solve and optimize the practical structural problems of the project. Through feedback adjustment of the response surface method, the center point and the search level range should be set artificially within the determined overall situation. In order to improve the efficiency of optimization. In the example of truss, the cooperative optimization is done, that is to say, considering the change of shape and size, both of them are optimized simultaneously. The difficulty lies in the mutual coupling between shape change and size change. The response surface method does not need Lagrange multiplier. Moreover, it can avoid the coupling between shape change and dimension change, and optimize the response surface by adjusting the test center and searching horizontal range. In the process of optimization, it is found that the truss bar 5 has coupling, and the form of stress concentration is stress concentration. Therefore, the size of A5 cross section should be increased. These are all artificially regulated by the experimenter. According to the feedback of response surface method, the design domain is adjusted manually. This is also the efficient source of response surface method. The shape optimization can be found by only three iterations, the size optimization can be found by two iterations, and the optimal solution of cooperative optimization design can be found by the last iteration. In the example of connecting rod and triangular arm, Soildworks is used to model and optimize with its own algorithm, but the precision of optimization is not high, so the quadratic optimization is carried out by response surface method, and the optimal solution is found in the best field.
【學(xué)位授予單位】：上海海洋大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TH122

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 李曼麗;楊志兵;;基于有限元分析的結(jié)構(gòu)優(yōu)化設(shè)計(jì)方法的研究[J];制造業(yè)自動(dòng)化;2013年18期

2 黃友欽;林俊宏;傅繼陽;吳玖榮;;多重約束下空間桁架結(jié)構(gòu)抗風(fēng)優(yōu)化[J];應(yīng)用數(shù)學(xué)和力學(xué);2013年08期

3 王春林;彭海菠;丁劍;劉棟;;基于響應(yīng)面法的消防泵S型葉片改進(jìn)優(yōu)化設(shè)計(jì)[J];機(jī)械工程學(xué)報(bào);2013年10期

4 呂輝;于德介;謝展;路懷華;;基于響應(yīng)面法的汽車盤式制動(dòng)器穩(wěn)定性優(yōu)化設(shè)計(jì)[J];機(jī)械工程學(xué)報(bào);2013年09期

5 Choon-Man Jang;Ka-Ram Choi;;Optimal Design of Splitters Attached to Turbo Blower Impeller by RSM[J];Journal of Thermal Science;2012年03期

6 張振偉;姚衛(wèi)星;周琳;張華;;桁架結(jié)構(gòu)尺寸和形狀協(xié)同優(yōu)化方法研究[J];航空工程進(jìn)展;2012年02期

7 姜衡;管貽生;邱志成;張憲民;陳忠;許冠;;基于響應(yīng)面法的立式加工中心動(dòng)靜態(tài)多目標(biāo)優(yōu)化[J];機(jī)械工程學(xué)報(bào);2011年11期

8 蔡新;李洪煊;武穎利;朱杰;;工程結(jié)構(gòu)優(yōu)化設(shè)計(jì)研究進(jìn)展[J];河海大學(xué)學(xué)報(bào)(自然科學(xué)版);2011年03期

9 賀青川;孫娟;陳文華;;響應(yīng)面方法在機(jī)構(gòu)設(shè)計(jì)中的應(yīng)用[J];機(jī)械設(shè)計(jì);2009年08期

10 竇毅芳;劉飛;張為華;;響應(yīng)面建模方法的比較分析[J];工程設(shè)計(jì)學(xué)報(bào);2007年05期

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