IF鋼成形極限的研究
發(fā)布時(shí)間：2018-11-17 19:05
【摘要】：IF鋼作為第三代深沖鋼材因其優(yōu)異的塑性變形能力,被廣泛應(yīng)用于汽車中的一些變形程度比較大的難成形零件。IF鋼的使用從某種程度上代表了一個(gè)國(guó)家的汽車工業(yè)水平的高低。我國(guó)汽車工業(yè)雖然已經(jīng)度過了發(fā)展最快的時(shí)期,但仍然處在一個(gè)高速發(fā)展的階段,對(duì)IF鋼的需求量很大。但一些汽車零部件廠并沒有對(duì)所使用板材的成形極限進(jìn)行研究,致使工藝分析與模具設(shè)計(jì)缺少判據(jù)。因此,研究IF鋼的成形極限,充分利用其塑性成形性能,進(jìn)而優(yōu)化成形工藝,提高汽車沖壓件質(zhì)量具有重要研究意義和價(jià)值。成形極限是板材塑性變形過程中在不失穩(wěn)的前提下達(dá)到最大應(yīng)變的極限狀態(tài),是衡量板材成形性能的重要指標(biāo)之一。通過實(shí)驗(yàn)獲取成形極限圖國(guó)內(nèi)、外都指定由相應(yīng)的標(biāo)準(zhǔn),但從試樣設(shè)計(jì)、制備到實(shí)驗(yàn)后的真實(shí)應(yīng)變測(cè)量和數(shù)據(jù)處理都耗時(shí)費(fèi)力,不便于應(yīng)用。本文以DX54D+Z為例,通過成形極限的實(shí)驗(yàn)研究、理論分析和數(shù)值模擬,探討用理論分析和成形模擬仿真方法快速獲取IF鋼成形極限圖的途徑。在實(shí)驗(yàn)研究方面,根據(jù)《金屬薄板成形性能實(shí)驗(yàn)-成形極限圖(FLD)實(shí)驗(yàn)》的規(guī)定,制作了矩形與階梯形9組(27件)試樣,矩形試樣用于獲取“拉-拉區(qū)”的應(yīng)變數(shù)據(jù),階梯形試樣用于獲取“拉-壓區(qū)”應(yīng)變數(shù)據(jù);采用電化學(xué)腐蝕法在板材上印制網(wǎng)格;利用杯突試驗(yàn)機(jī)完成成形實(shí)驗(yàn);利用GMASystem系統(tǒng)進(jìn)行網(wǎng)格應(yīng)變自動(dòng)測(cè)量;最終完成實(shí)驗(yàn)成形極限圖的繪制,為后續(xù)理論分析與成形模擬提供參考。在理論分析上,基于M-K凹槽理論,利用Logan-Hosford屈服準(zhǔn)則和Rossard硬化方程,建立了板材成形極限預(yù)測(cè)數(shù)學(xué)模型,結(jié)合弦截法迭代求解,通過MATLAB軟件對(duì)DX54D+Z的成形極限圖進(jìn)行了理論預(yù)測(cè)。在此基礎(chǔ)上,分析了不同屈服準(zhǔn)則、應(yīng)變強(qiáng)化指數(shù)、應(yīng)變速率敏感系數(shù)和厚度不均值對(duì)理論預(yù)測(cè)的影響。在成形模擬方面,應(yīng)用DYNAFORM軟件對(duì)標(biāo)準(zhǔn)埃里克森杯突實(shí)驗(yàn)過程進(jìn)行成形模擬。但由于有限元軟件沒有失穩(wěn)判據(jù)判斷材料破壞或是虛擬實(shí)驗(yàn)停止的時(shí)間節(jié)點(diǎn),本文在分析應(yīng)力應(yīng)變狀態(tài)的基礎(chǔ)上,提出極限狀態(tài)的判據(jù),對(duì)比分析了不同判據(jù)的使用范圍,并預(yù)測(cè)了IF鋼的成形極限圖,討論了實(shí)驗(yàn)工藝參數(shù)對(duì)基于成形模擬預(yù)測(cè)結(jié)果的影響。最后,將理論和成形模擬成形極限圖與實(shí)驗(yàn)成形極限圖進(jìn)行對(duì)比,驗(yàn)證了理論和模擬方法的可行性和結(jié)果的正確性,為零部件廠商在實(shí)際生產(chǎn)中快速獲取成形極限圖提供了新的途徑。
[Abstract]:As the third generation deep drawing steel, IF steel has excellent plastic deformation ability. The use of IF steel represents the level of automobile industry in a country to a certain extent. Although the automobile industry of our country has passed the period of the fastest development, it is still in a stage of high speed development, and the demand for IF steel is very large. However, some automobile parts factories do not study the forming limit of the sheet metal used, which leads to the lack of criteria for process analysis and die design. Therefore, it is of great significance and value to study the forming limit of IF steel, make full use of its plastic formability, optimize the forming process and improve the quality of automotive stamping parts. Forming limit is the limit state of the maximum strain in the process of sheet metal plastic deformation, and it is one of the important indexes to evaluate the forming performance of sheet metal. At home and abroad, the corresponding standard is assigned to obtain the forming limit diagram by experiment. However, from sample design, preparation to the real strain measurement and data processing after experiment, it is time-consuming and difficult to apply. In this paper, taking DX54D Z as an example, through the experimental study, theoretical analysis and numerical simulation of the forming limit, the way to obtain the forming limit diagram of IF steel quickly by theoretical analysis and simulation method is discussed. In the aspect of experimental study, according to the rule of "sheet metal formability experiment-forming limit diagram (FLD) experiment", 9 groups of rectangular and stepped specimens (27 pieces) were made. The rectangular specimen was used to obtain the strain data of "pull-pull zone". The step specimen is used to obtain the strain data of "tension and compression zone"; The electrochemical etching method is used to print the mesh on the sheet metal, the forming experiment is completed by the cupping test machine, and the mesh strain is measured automatically by GMASystem system. Finally, the drawing of the experimental forming limit diagram is completed, which provides a reference for the subsequent theoretical analysis and forming simulation. Based on M-K grooves theory and Logan-Hosford yield criterion and Rossard hardening equation, a mathematical model of sheet metal forming limit prediction is established. The forming limit diagram of DX54D Z is predicted by MATLAB software. On this basis, the effects of different yield criteria, strain strengthening exponent, strain rate sensitivity coefficient and thickness non-mean on the theoretical prediction are analyzed. In the aspect of forming simulation, DYNAFORM software is used to simulate the standard Eriksson cupping process. But because the finite element software does not have the instability criterion to judge the time node of material failure or virtual experiment stop, based on the analysis of stress-strain state, the criterion of limit state is put forward, and the application range of different criterion is compared and analyzed. The forming limit diagram of IF steel is predicted and the influence of experimental process parameters on the prediction results based on forming simulation is discussed. Finally, the theoretical and simulated forming limit diagrams are compared with the experimental forming limit diagrams to verify the feasibility of the theory and simulation methods and the correctness of the results. It provides a new way for parts manufacturers to obtain rapid forming limit diagram in actual production.
【學(xué)位授予單位】：武漢理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TG301;TG142.1
本文編號(hào)：2338776
[Abstract]:As the third generation deep drawing steel, IF steel has excellent plastic deformation ability. The use of IF steel represents the level of automobile industry in a country to a certain extent. Although the automobile industry of our country has passed the period of the fastest development, it is still in a stage of high speed development, and the demand for IF steel is very large. However, some automobile parts factories do not study the forming limit of the sheet metal used, which leads to the lack of criteria for process analysis and die design. Therefore, it is of great significance and value to study the forming limit of IF steel, make full use of its plastic formability, optimize the forming process and improve the quality of automotive stamping parts. Forming limit is the limit state of the maximum strain in the process of sheet metal plastic deformation, and it is one of the important indexes to evaluate the forming performance of sheet metal. At home and abroad, the corresponding standard is assigned to obtain the forming limit diagram by experiment. However, from sample design, preparation to the real strain measurement and data processing after experiment, it is time-consuming and difficult to apply. In this paper, taking DX54D Z as an example, through the experimental study, theoretical analysis and numerical simulation of the forming limit, the way to obtain the forming limit diagram of IF steel quickly by theoretical analysis and simulation method is discussed. In the aspect of experimental study, according to the rule of "sheet metal formability experiment-forming limit diagram (FLD) experiment", 9 groups of rectangular and stepped specimens (27 pieces) were made. The rectangular specimen was used to obtain the strain data of "pull-pull zone". The step specimen is used to obtain the strain data of "tension and compression zone"; The electrochemical etching method is used to print the mesh on the sheet metal, the forming experiment is completed by the cupping test machine, and the mesh strain is measured automatically by GMASystem system. Finally, the drawing of the experimental forming limit diagram is completed, which provides a reference for the subsequent theoretical analysis and forming simulation. Based on M-K grooves theory and Logan-Hosford yield criterion and Rossard hardening equation, a mathematical model of sheet metal forming limit prediction is established. The forming limit diagram of DX54D Z is predicted by MATLAB software. On this basis, the effects of different yield criteria, strain strengthening exponent, strain rate sensitivity coefficient and thickness non-mean on the theoretical prediction are analyzed. In the aspect of forming simulation, DYNAFORM software is used to simulate the standard Eriksson cupping process. But because the finite element software does not have the instability criterion to judge the time node of material failure or virtual experiment stop, based on the analysis of stress-strain state, the criterion of limit state is put forward, and the application range of different criterion is compared and analyzed. The forming limit diagram of IF steel is predicted and the influence of experimental process parameters on the prediction results based on forming simulation is discussed. Finally, the theoretical and simulated forming limit diagrams are compared with the experimental forming limit diagrams to verify the feasibility of the theory and simulation methods and the correctness of the results. It provides a new way for parts manufacturers to obtain rapid forming limit diagram in actual production.
【學(xué)位授予單位】：武漢理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TG301;TG142.1
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 陳水生;唐春紅;;基于人工神經(jīng)網(wǎng)絡(luò)的拼焊板成形極限圖預(yù)測(cè)[J];塑性工程學(xué)報(bào);2014年04期
2 侯波;于忠奇;李淑慧;林忠欽;;溫成形中鋁合金板成形極限圖的預(yù)測(cè)研究[J];材料科學(xué)與工藝;2009年05期
3 曹宏深;林敦文;關(guān)紹康;;沖壓成形極限圖虛擬試驗(yàn)[J];農(nóng)業(yè)機(jī)械學(xué)報(bào);2007年01期
4 余海燕;高云凱;;基于M-K模型的相變誘發(fā)塑性鋼板的成形極限研究[J];中國(guó)機(jī)械工程;2007年01期
5 王輝;高霖;趙明琦;;一種基于有限元仿真的板料成形極限預(yù)測(cè)方法[J];山東大學(xué)學(xué)報(bào)(工學(xué)版);2006年02期
6 李文彬,官軍;深沖鋼(IF鋼)的研究與發(fā)展概況[J];冶金設(shè)備;2005年03期
7 郭正華,李志剛,歐陽(yáng)可居,董湘懷;5182鋁合金板溫成形工藝及摩擦學(xué)特性的研究[J];鍛壓裝備與制造技術(shù);2003年06期
8 周賢賓;塑性加工技術(shù)的發(fā)展——更精、更省、更凈[J];中國(guó)機(jī)械工程;2003年01期
9 馬鳴圖;我國(guó)汽車鋼板研究與應(yīng)用進(jìn)展[J];鋼鐵;2001年08期
10 李碩本,金淼,彭加耕;關(guān)于板材加工硬化性能評(píng)定方法的探討[J];塑性工程學(xué)報(bào);2001年02期
相關(guān)博士學(xué)位論文 前1條
1 王輝;成形極限圖的獲取方法與其在金屬板料成形中的應(yīng)用[D];南京航空航天大學(xué);2011年
相關(guān)碩士學(xué)位論文 前1條
1 翟妮芝;數(shù)值模擬在板材成形極限分析中的應(yīng)用[D];西北工業(yè)大學(xué);2007年
，本文編號(hào)：2338776
本文鏈接：http://www.sikaile.net/kejilunwen/jinshugongy/2338776.html
最近更新
教材專著
