本文選題：鑄態(tài)7075鋁合金　切入點：筒形件　出處：《南昌航空大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：鑄態(tài)7075鋁合金薄壁筒形件由于具有質(zhì)量輕、強度高和耐腐蝕強等優(yōu)點,廣泛應(yīng)用于航空航天等技術(shù)領(lǐng)域。多道次強力熱反旋成形是加工此類薄壁筒形件的最有效方法之一。然而,鼓包是筒形件旋壓過程中常見的缺陷之一,它嚴(yán)重制約著筒形件成形質(zhì)量和成形極限的提高。為此,本文采用均勻正交試驗,針對該筒形件進(jìn)行了多道次強力熱反旋有限元數(shù)值模擬。并結(jié)合旋壓實驗,對該筒形件旋壓過程基于鼓包的成形極限進(jìn)行研究。主要的研究內(nèi)容和成果如下:(1)本文基于ABAQUS/Explicit有限元平臺,完善了已有的鑄態(tài)7075鋁合金筒形件多道次強力熱反旋三維熱力耦合彈塑性有限元模型。(2)采用方差分析法對均勻正交試驗數(shù)據(jù)進(jìn)行處理分析,并考慮到工藝參數(shù)與鼓包高度耦合的關(guān)系模型和鼓包極限預(yù)測模型的建立,每一道次均取影響鼓包較大的3個工藝參數(shù)。影響筒形件第一、二、三、四道次鼓包高度的顯著性工藝參數(shù)依次取為:sv、mT、s?;mT、mn、(35)t;(35)t、sv、mT;sv、mn、mT。(3)采用極差分析法對均勻正交試驗結(jié)果進(jìn)行處理分析,并對比分析驗證性試驗結(jié)果,獲得各道次最優(yōu)工藝參數(shù)組合:在第一道次,壓下量(35)t取2.4mm,芯模預(yù)熱溫度mT取220℃,芯模轉(zhuǎn)速mn取3.0r·s-1,旋輪進(jìn)給速度sv取0.6mm·s-1,芯模與工件間摩擦m?取0.15,旋輪與工件間摩擦s?取0.35。第二、三、四道次的(35)t、mT、mn、sv、m?、s?分別取值:2.4、200、3.5、0.8、0.15、0.30;1.9、100、4.0、0.6、0.15、0.35;1.4、100、4.0、0.6、0.20、0.45。(4)基于對筒形件鼓包影響的顯著性工藝參數(shù),建立了各道次工藝參數(shù)與鼓包高度耦合的關(guān)系模型,推導(dǎo)出了各道次鼓包極限預(yù)測模型。獲得工藝參數(shù)對各道次鼓包極限的影響規(guī)律:第一道次鼓包極限隨著sv的增大先減小后增大,隨著s?的增大而增大;第二道次鼓包極限隨著mn的增大先減小后變化不大,隨著(35)t的增大而減小;第三道次鼓包極限隨著(35)t的增大先減小后增大,隨著sv的增大而增大;第四道次鼓包極限隨著sv、mn的增大均先減小后變化不大。此外,還建立了筒形件各道次鼓包極限圖。
[Abstract]:The as-cast 7075 aluminum alloy thin-walled cylindrical parts have the advantages of light weight, high strength and strong corrosion resistance. It is widely used in aerospace and other technical fields. Multi-pass hot reverse forming is one of the most effective methods to process this kind of thin-walled cylindrical parts. However, the drum is one of the common defects in the spinning process of cylindrical parts. It seriously restricts the improvement of forming quality and forming limit of cylindrical workpiece. In this paper, the finite element numerical simulation of multi-pass strong thermal counter-rotation is carried out for the cylindrical part by uniform orthogonal test, and combined with spinning experiment, The forming limit of spinning process based on drum is studied. The main research contents and results are as follows: (1) this paper is based on ABAQUS/Explicit finite element platform. In this paper, the existing finite element model of multi-pass strong thermal inverse rotation three dimensional coupled elastoplastic finite element method for as-cast 7075 aluminum alloy cylindrical parts is improved. The uniform orthogonal test data are processed by variance analysis method. Considering the relationship between the process parameters and the height coupling of the bulge and the establishment of the model for predicting the limit of the bulge, the three technological parameters affecting the bulge are taken for each time, which affect the first, second, and third parts of the cylindrical part. The significant technological parameters of the height of the four times of bulging were taken as: 1% svvm TX? The uniform orthogonal test results were processed and analyzed by using the range analysis method, and the results of the validation tests were compared and analyzed. The optimum technological parameters of each pass were obtained: in the first time, the reduction of 35 t was 2.4 mm, the preheating temperature of the core mould was 220 鈩，

本文編號：1558027