(1. 華僑大學(xué) 機電及自動化學(xué)院，廈門 361021;
2. 哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱 150001)
摘 要: 從力學(xué)角度出發(fā)提出隨焊超聲波激振控制高強硬鋁合金薄板焊接變形的新方法，闡明其控制焊接應(yīng)力及變形的機理。基于數(shù)值模擬分析，利用Marc建立鋁合金薄板的隨焊超聲波激振熱力耦合模型，找出最優(yōu)焊接參數(shù)以及加載沖擊與熱源的最佳距離。利用自行研制的隨焊超聲波激振裝置進行焊接試驗。結(jié)果表明：激振距離為22 mm時，板長方向中截面殘余拉應(yīng)力峰值由常規(guī)焊的248 MPa下降到63 MPa，壓應(yīng)力峰值從-77 MPa降低到-27 MPa，低于薄板的臨界失穩(wěn)應(yīng)力，薄板撓曲變形完全消失，且板邊最大撓度由8.66 mm下降到0.9 mm。試驗結(jié)果與模擬結(jié)果吻合較好。
關(guān)鍵字: 隨焊超聲波激振；數(shù)值模擬；焊接殘余應(yīng)力；撓曲變形
（1. College of Mechanical Engineering and Automation, Huaqiao University, Xiamen 361021, China;
2. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China）
Abstract:A new method of welding with trailing ultrasonic vibration (WTUV) to control the welding distortion of high strength aluminum alloy sheet was put forward, and the mechanism was illustrated. Based on numerical simulation analysis, the model of thermo-mechanical coupled welding with ultrasonic vibration was established using Marc software. The optimal welding parameters and the best distance between the vibrating position and heat source are obtained. The welding experiments were conducted on the self-developed device. The results show that when the distance between vibrating point and heat source is 22 mm, the residual tensile stress in the middle cross-section in longitudinal direction reduces from 248 MPa of conventional welding to 63 MPa. The maximum compressive residual stress reduces from -77 MPa to -27 MPa, which is below the critical buckling stress of the sheet, the deflection distortion disappears entirely, and the maximum deflection of plate edges drops from 8.66 mm to 0.9 mm. There are better agreements between the test results and simulation results.
Key words: welding with trailing ultrasonic vibration; numerical simulation; welding residual stress; deflection distortion
