本文選題：漸進(jìn)成形　切入點(diǎn)：優(yōu)化設(shè)計(jì)　出處：《浙江工業(yè)大學(xué)》2015年碩士論文

【摘要】：金屬板材在數(shù)控漸進(jìn)成形過程中,經(jīng)歷了復(fù)雜的應(yīng)力、應(yīng)變變化過程,零件在加工過程中會(huì)存在各種缺陷,為提高成形件的質(zhì)量和精度,需要對漸進(jìn)成形機(jī)理進(jìn)行深入的研究,并在此基礎(chǔ)上對漸進(jìn)成形進(jìn)行優(yōu)化分析,通過合理的選擇成形過程中的工藝參數(shù),設(shè)計(jì)合理的工具頭路徑,避免成形過程中出現(xiàn)過度減薄和板材破裂的情況�；谒苄粤W(xué)理論對漸進(jìn)成形的應(yīng)力、應(yīng)變和板厚分布進(jìn)行理論計(jì)算,在此基礎(chǔ)上模擬了單點(diǎn)漸進(jìn)成形有限元仿真的過程,解決了數(shù)值模擬中的關(guān)鍵問題:包括單元選擇、材料模型選擇、接觸處理和路徑加載等問題,并將模擬結(jié)果與理論計(jì)算對比,證明有限元模型的有效性。在此有限元模型的基礎(chǔ)上對漸進(jìn)成形進(jìn)行優(yōu)化設(shè)計(jì),主要包括軌跡優(yōu)化和參數(shù)優(yōu)化兩個(gè)部分,對比得到螺旋線進(jìn)給方式相較于直線進(jìn)給方式能提高板材成形性能;采用多道次成形設(shè)計(jì)能解決成形件板厚分布不均勻的情況,并能加工出成形角度超過成形極限的制件。參數(shù)優(yōu)化主要確定了工具頭直徑、板材厚度、成形角度和單層進(jìn)給量對漸進(jìn)成形性能的影響,進(jìn)一步通過正交試驗(yàn)確定影響板材漸進(jìn)成形減薄率的主要因素是成形角度、進(jìn)給量與工具頭直徑,次要因素是板材厚度。利用響應(yīng)面法,建立了多參數(shù)回歸方程,量化了各參數(shù)對板材減薄率的影響,提出了一種綜合考慮多參數(shù)的預(yù)測板材減薄率的方法;在此基礎(chǔ)上建立了減薄率響應(yīng)面優(yōu)化模型,采用二次規(guī)劃優(yōu)化算法(SQP)迭代求解目標(biāo)函數(shù)的最優(yōu)解,并根據(jù)優(yōu)化分析結(jié)果加工出厚度分布較為均勻的汽車翼子板。
[Abstract]:In the process of numerical control progressive forming, metal sheet has experienced complex stress and strain changes, and parts will have various defects in the process of machining. In order to improve the quality and accuracy of forming parts, it is necessary to deeply study the mechanism of progressive forming. On the basis of this, the paper optimizes and analyzes the gradual forming process, and designs a reasonable tool head path by selecting the process parameters in the forming process. Based on the plastic mechanics theory, the stress, strain and plate thickness distribution of progressive forming are calculated theoretically, and the finite element simulation process of single point incremental forming is simulated based on the theory of plastic mechanics. The key problems in numerical simulation are solved, including element selection, material model selection, contact treatment and path loading, and the simulation results are compared with theoretical calculation. It is proved that the finite element model is effective. On the basis of the finite element model, the design of incremental forming is optimized, which includes two parts: trajectory optimization and parameter optimization. The results show that the helical feeding method can improve the sheet metal forming performance compared with the linear feed method, and the multi-pass forming design can solve the problem of uneven thickness distribution of the forming parts. The influence of tool head diameter, sheet thickness, forming angle and monolayer feed on the incremental forming performance is determined. Through orthogonal test, it is determined that the main factors affecting the thinning rate of sheet metal progressive forming are forming angle, feed rate and tool head diameter, and the secondary factor is sheet thickness. By using the response surface method, the multi-parameter regression equation is established. This paper quantifies the influence of each parameter on the thinning rate of the plate, and puts forward a method of predicting the thinning rate of the plate considering multiple parameters synthetically, and establishes the response surface optimization model of the thinning rate on the basis of the method. The quadratic programming optimization algorithm (SQP) is used to iteratively solve the optimal solution of the objective function. According to the results of the optimization analysis, the uniform thickness distribution of the automobile airfoil is obtained.
【學(xué)位授予單位】：浙江工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TG306

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 李茂君;基于數(shù)值模擬的板材漸進(jìn)成形回彈研究[D];華中科技大學(xué);2008年

，

本文編號(hào)：1672334