本文選題：單層球形網(wǎng)殼結(jié)構(gòu) + 焊接工藝��； 參考：《鄭州大學(xué)》2017年碩士論文

【摘要】：焊接是工業(yè)生產(chǎn)中非常重要的一種連接形式,其中的氣體保護焊廣泛應(yīng)用在各個領(lǐng)域。但是由于焊接過程是運動的熱源且焊件局部受熱,使得焊后存在難以避免的變形和殘余應(yīng)力,但合理的焊接工藝可以顯著改善焊件性能。本文針對空間網(wǎng)殼單層球形網(wǎng)殼中典型三角形焊接結(jié)構(gòu)的主要部分進行焊接工藝研究。首先采用SolidWorks建立三維模型,然后導(dǎo)入Simufact.Mesh.Simulab進行網(wǎng)格劃分,最后采用Simufact.Welding軟件對該焊接結(jié)構(gòu)進行應(yīng)力和變形數(shù)值分析。研究的焊接工藝參數(shù)包括:焊接中點固焊順序、數(shù)量、位置,以及焊接速度、焊接電壓、預(yù)熱溫度、約束位置、焊炬?zhèn)�數(shù)等。并通過試驗方法測出焊點數(shù)量為3時的Y向變形量與軟件求解所得跟蹤點結(jié)果進行對比驗證。對以上所述焊接工藝參數(shù)的研究,得出以下結(jié)論:焊點數(shù)量多少與奇偶性對焊后應(yīng)力和變形影響很大;點焊順序(取三個焊點時),中間焊點最后焊接時,最大綜合變形和等效應(yīng)力峰值都最小;點焊位置的影響同樣很大,當(dāng)點焊在兩個焊縫同時施焊或者只在焊縫2一側(cè)時,變形和應(yīng)力都比較小;焊接速度提高時焊接變形有一定波動,但等效應(yīng)力卻有明顯增大趨勢;隨著電壓變化,變形和應(yīng)力也有類似的變化;約束位置改變時,當(dāng)夾持位置在中間時等效應(yīng)力最小,焊接變形受夾持位置影響比等效應(yīng)力小;預(yù)熱溫度對焊接變形和應(yīng)力影響呈現(xiàn)先降低再升高的趨勢,在100℃時取得最小值;焊槍個數(shù)用兩個時兩側(cè)同時施焊,比只用一個焊槍焊接效果好。焊接過程中工藝參數(shù)選擇很關(guān)鍵,而這些參數(shù)對焊接質(zhì)量的影響根本在于焊接輸入的熱(多少、快慢、分布等)和外界機械約束(約束形式、卸載時間等)綜合作用。
[Abstract]:Welding is a very important form of connection in industrial production, in which gas shielded welding is widely used in various fields. However, the welding process is the heat source of movement and the welding part is locally heated, which makes it difficult to avoid deformation and residual stress after welding. However, reasonable welding process can significantly improve the properties of welding parts. In this paper, the welding technology of typical triangular welded structure in single layer spherical reticulated shell is studied. Firstly, SolidWorks is used to build 3D model, then Simufact.Mesh.Simulab is imported to mesh. Finally, the stress and deformation of the welded structure are analyzed numerically by Simufact.Simulab. The welding process parameters are as follows: sequence, quantity, position, welding speed, welding voltage, preheating temperature, constraint position, number of torch, etc. The Y-direction deformation with the number of solder joints 3 is measured by the test method and compared with the results obtained by the software. By studying the welding process parameters mentioned above, the following conclusions are drawn: the number of solder joints has a great influence on the stress and deformation after welding with odd and even butt welding, and the spot welding sequence (when three solder joints are taken, when the middle solder joint is finally welded), The maximum comprehensive deformation and the peak equivalent stress are the smallest, and the effect of spot welding position is also very great. When the spot welding is carried out at the same time or only on the two sides of the weld, the deformation and stress are relatively small. With the increase of welding speed, the welding deformation fluctuates, but the equivalent stress increases obviously; with the change of voltage, the deformation and stress have similar changes; when the constraint position changes, the equivalent stress is the smallest when the clamping position is in the middle. The welding deformation is less affected by clamping position than equivalent stress, the effect of preheating temperature on welding deformation and stress decreases first and then increases, and the minimum value is obtained at 100 鈩，

本文編號：2018672