【摘要】：多通管在工業(yè)領域應用廣泛,是各種中高壓管路系統(tǒng)中必不可少的基礎元件之一,而多通管的生產卻一直是最困難的工藝之一。多通管的生產,已逐漸由傳統(tǒng)的焊接、機加工和鑄造等方法,過渡到脹形成形方法。多通管脹形是在壓力作用下使管材沿徑向擴張的成形工藝,是一種少無切削加工,半精/精成形技術,屬于先進制造技術范疇。本文以三通管為典型零件,對以橡膠彈性體為脹形介質的多通管脹形工藝進行研究。由于多通管脹形過程既包含材料非線性,又有幾何非線性和邊界非線性的特點,選取非線性顯式有限元分析程序ANSYS/LS-DYNA為數(shù)值模擬平臺,對成形工藝參數(shù)和加載路徑進行優(yōu)化。 工藝參數(shù)優(yōu)化。管坯參數(shù)優(yōu)化:建立三通管脹形有限元模型,結合正交設計的思想獲取訓練、測試樣本;采用Elman人工神經網絡構建管坯料參數(shù)預測模型,以管坯長度、管坯壁厚和模具過渡圓角半徑為網絡輸入參數(shù),壁厚增減量不超過30%時的最大支管長度為輸出參數(shù);在MATLAB軟件平臺上完成預測網絡的建立、訓練、測試和管坯參數(shù)預測優(yōu)化,得到圓角半徑R=7 mm,壁厚t=1.5 mm,長度l0=100 mm的坯料參數(shù)。分析摩擦對成形影響:對管坯與模具摩擦系數(shù)μ1、橡膠棒與管坯摩擦系數(shù)μ2進行方案設計,引入評價函數(shù)并結合橡膠壽命考慮,得到最優(yōu)組合μ1 = 0.1,μ2 = 0.35。 復合脹形加載路徑優(yōu)化。對復合脹形反壓的施加方式和加載路徑進行了設計。對軸向加壓脹形時支管高度隨時間變化進行線性簡化,選擇反壓沖頭與支管開始接觸時高度h0和反壓沖頭移動速度V3代替反壓F3的施加,確定了h0 = 6 mm、反壓沖壓速度V3與軸向擠壓沖頭V1的速度比值V3/V1 = 1,軸壓沖頭小端長度l1 = 5mm的復合脹形方案,并得到較理想支管長度的三通管件。通過三通管軸向加壓和復合脹形的壁厚分析、應變應力分析及支長度分析,表明復合脹形管件壁厚減薄更緩慢,壁厚分布更均勻,最終得到更大的支管長度,驗證了復合脹形工藝的優(yōu)越性。
[Abstract]:Multi-way pipe is widely used in industrial field and is one of the essential basic components in various medium-high pressure pipeline systems, but the production of multiway pipe has been one of the most difficult processes. The production of multiway pipe has gradually changed from traditional welding, machining and casting to bulging forming method. Multipass tube bulging is a kind of forming technology which makes the tube expand along the radial direction under the action of pressure. It is a kind of less cutting and semi-fine / fine forming technology, which belongs to the advanced manufacturing technology category. In this paper, the bulging process of multipass tube with rubber elastomer as bulging medium is studied. Because the bulging process of multichannel tube includes material nonlinearity, geometric nonlinearity and boundary nonlinearity, the nonlinear explicit finite element analysis program ANSYS/LS-DYNA is chosen as the numerical simulation platform. The process parameters and loading path are optimized. Optimization of process parameters. Optimization of tube billet parameters: the finite element model of tube bulging was established, and the training and test samples were obtained based on the idea of orthogonal design. The Elman artificial neural network is used to build the prediction model of pipe billet parameters. The network input parameters are the length of the billet, the wall thickness of the billet and the radius of the transition corner of the die, and the maximum length of the branch pipe when the increase or decrease of the wall thickness is not more than 30 is the output parameter. The prediction network was established, trained, tested and optimized on the platform of MATLAB software, and the billet parameters of r-7 mm, wall thickness t _ (1.5) mm, ~ (-1) mm, ~ (100) mm were obtained. The influence of friction on forming was analyzed. The scheme design of friction coefficient 渭 1 between tube and die and friction coefficient 渭 2 between rubber rod and tube blank was carried out. The optimum combination 渭 1 = 0.1, 渭 2 = 0.35 was obtained by introducing evaluation function and considering rubber life. Compound bulging loading path optimization. The application mode and loading path of compound bulging back pressure are designed. The variation of branch height with time during axial pressure bulging is linear simplified. The height h _ 0 and the moving speed V _ 3 of the back pressure punch are chosen to replace the applied of the back pressure F _ 3 when the back pressure punch and the branch pipe are in contact with the branch tube, and the H _ 0 = 6 mm, is determined. The ratio of the velocity of V3 to V1 of the axial extrusion punch is V3/V1 = 1, the length of the small end of the axial press punch is 1 = 5mm, and the tri-way pipe fitting with ideal branch length is obtained. Through the wall thickness analysis, strain stress analysis and support length analysis of the axial compression and compound bulging of the three-way tube, it is shown that the wall thickness of the compound bulging tube is reduced more slowly, the distribution of the wall thickness is more uniform, and finally the larger branch length is obtained. The superiority of compound bulging process is verified.
【學位授予單位】：華僑大學
【學位級別】：碩士
【學位授予年份】：2011
【分類號】：TH136

【引證文獻】

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1 王玲;付冬雪;郎利輝;王少華;楊春雷;;大比例三通接頭成形工藝研究及質量控制[J];鍛壓技術;2013年02期

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本文編號：2308979