本文關鍵詞：基于APDL語言T型接頭雙側同步焊有限元建模及在鋼結構變形預測中應用研究　出處：《重慶交通大學》2015年碩士論文　論文類型：學位論文

  更多相關文章： T型接頭 雙側同步焊 有限元 固有應變 鋼結構

【摘要】：焊接結構具有整體性強、致密性好、經濟實惠和適用于各種外形尺寸的零件等優(yōu)點,在被廣泛的應用于國民經濟各部門中。但是焊接工藝也存在比較突出的問題,例如焊后工件中會產生較大的殘余應力和殘余變形。焊后應力和變形會影響工件的加工精度和使用性能。所以,為了達到優(yōu)化工藝的目的需要了解不同焊接工藝的焊后殘余應力和變形的大小分布。焊接數(shù)值模擬的方法可以在不具備實驗條件的情況下進行研究,可以大幅度降低成本。同時,還可以預測焊接變形結果、模擬計算焊接過程以及進行焊接參數(shù)和焊接結構的優(yōu)化,對實際焊接工藝進行指導。正是由于這些優(yōu)點,焊接數(shù)值模擬技術越來越受到重視。本文主要針對T型接頭的雙側同步焊接工藝,基于APDL語言建立了焊接過程模擬分析的有限元模型,并通過焊接實驗驗證了模型的準確性。通過對比分析T型接頭雙側同步焊與順序焊接的模擬結果,發(fā)現(xiàn)雙側同步焊接可以有效的減小應力和變形分布不均,焊接收弧端的殘余應力明顯大于其他區(qū)域。利用建立的新模型對大型橋梁鋼箱梁中應用雙側同步焊接工藝的部分結構行了模擬計算,得到了焊接過程溫度變化和焊后殘余應力和殘余變形結果。模擬結果表明焊接最大變形主要集中在頂板邊緣,焊接殘余應力集中于焊縫附近,并且應力值較大。在熱彈塑性法模擬結果的基礎上,本文還對T型接頭雙側同步焊接固有變形分布進行了研究,結果表明沿焊縫方向的橫向收縮變形先增大后減小,在起弧和收弧端由于端部效應橫向固有變形略高于其附近的金屬。縱向固有變形沿焊縫方向由兩端向中間逐漸減小,角變形從焊接起點沿焊縫方向逐漸增大。同時,分別研究了焊接速度、焊接順序、腹板厚度、翼板厚度和翼板寬度對固有應變的影響,結果表明,焊接速度、腹板厚度和翼板厚度對固有應變有較大影響,翼板寬度和焊接順序在一定的范圍內對固有應變有影響。通過對比熱彈塑性法和固有應變計算的T型接頭殘余變形,發(fā)現(xiàn)兩種方法得到的變形分布和沿翼板垂向的撓度基本吻合,驗證了固有應變法預測變形的可靠性。同時,對比了殼單元和實體單元的固有應變預測T型接頭焊接變形結果,發(fā)現(xiàn)兩者結果差別較小,說明采用殼單元進行計算就能達到很好的精度。然后,利用熱彈塑性法計算獲得大型橋梁鋼箱梁各接頭的平均固有應變,并應用于大型橋梁鋼結構焊接模塊的變形預測計算,通過分析變形結果對焊接工藝提出了相關的一些建議。
[Abstract]:With strong integrity of welded structure, compact, economical and applicable to various shapes and sizes of the parts in the advantages, has been widely used in various sectors of the national economy. But the welding process there are many problems, such as welding workpiece will produce larger residual stress and welding residual deformation. Stress and deformation will affect the machining accuracy and performance. So, in order to need to understand the different welding process to optimize the welding residual stress and deformation after welding. The size distribution of the numerical simulation method can be studied in the experiment does not have the condition, can greatly reduce the cost at the same time. Also, can predict welding deformation results, simulation of welding process and welding parameters and welding structure optimization, the actual welding process. It is because of these advantages, the welding numerical Simulation technology has been paid more and more attention. This article mainly aims at the bilateral T joint synchronous welding process, the APDL language to establish a finite element analysis of welding process based on the model, and the accuracy of the model was verified by welding experiments. Through comparative analysis of simulation results of T type joint bilateral synchronous welding and welding, welding can be found in bilateral synchronization effectively reduce the stress and deformation of the uneven distribution of welding residual stress of the arc end is greater than that of other areas. Some structures using a new model of bilateral large bridge steel box girder synchronous welding process were simulated and calculated, the process of welding temperature and the welding residual stress and residual deformation simulation results. The results show that the welding deformation is mainly concentrated in the edge of the top plate, the welding residual stress in the weld, and the stress is larger. The thermal elastic plastic mold Based on the results of this paper intends to, for the T type joint bilateral synchronous welding inherent deformation distribution were studied. The results show that the transverse shrinkage deformation along the weld direction increases first and then decreases, arc starting and stopping at the end due to the end effect of lateral natural deformation is slightly higher than in the vicinity of the metal. The longitudinal natural deformation along the weld direction from both ends to the center gradually decreases, angular distortion from the welding starting point increases gradually along the direction of weld were studied. At the same time, welding speed, welding sequence, web thickness, flange thickness, flange width and the inherent strain. The results show that the welding speed, the thickness of the thickness of web and flange has great influence on the inherent strain, wing plate the width and welding sequence have influence on the inherent strain in a certain range. The T type joint by comparing the thermal elastic plastic inherent strain method and calculation of residual deformation, deformation distribution obtained by the two methods Along the vertical deflection and wing plate are basically consistent, verify the inherent strain deformation prediction reliability. At the same time, compared the inherent strain shell element and solid element prediction T joint welding deformation results, both found little difference between the results, using shell element calculation can achieve good accuracy. Then, using the thermo elastic plastic inherent strain method to calculate the average for each joint of the steel box girder bridge, deformation prediction and its application in large bridge steel structure welding deformation calculation module, through the analysis of results and put forward some suggestions related to the welding process.

【學位授予單位】：重慶交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TG404

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本文編號：1409019