超声喷丸控制铝合金大型薄壁结构焊接应力与变形机理及关键技术研究

项目名称： 超声喷丸控制铝合金大型薄壁结构焊接应力与变形机理及关键技术研究

项目编号： No.51275343

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 机械、仪表工业

项目作者： 王东坡

作者单位： 天津大学

项目金额： 80万元

中文摘要： 针对大型运载火箭制造及导弹服役过程贮存延寿工程中亟待解决的大型铝合金薄壁结构焊接应力与变形问题，本项目提出超声喷丸控制焊接残余应力的新方法，在消除或调整焊接残余应力、矫正变形的同时改善焊接构件性能。具体实施以控制铝合金薄壁焊接结构最易出现的失稳变形为切入点，建立超声喷丸物理过程模型，获得超声喷丸参数（振幅、冲击针直径、移动速度）、材料力学性能（高速撞击下屈服强度和弹性模量）与冲击针速度的数学模型，获得冲击针最大速度；采用试验与有限元相结合的方式，获得焊接预应力和预变形条件下超声喷丸矫形过程中应力场的演变规律，阐明超声喷丸控制焊接结构应力与变形的机理；在此基础上确定超声喷丸位置和参数，建立超声喷丸工艺-试件残余应力分布、微观结构、缺陷行为-试件变形、腐蚀性能、拉伸性能之间的关系，获得最优超声喷丸工艺。开发具有自主知识产权的大功率、自动化超声喷丸设备，为大型复杂结构应力与变形控制提供支持。

中文关键词： 超声喷丸；本构关系；冲击针速度；失稳变形；残余应力

英文摘要： To meet the requirement of controlling the welding stress and deformations in Al alloy large thin wall structure used in freight rocket and guided missile, the new techinique of ultrasonic peening controlling welding residual stress is put forward in this study. The structure peformances can be improved while the stress is relieved by this techinique. The structure peformances can be improved while the stress is relieved by this techinique. This study focucs on buckling distortion, for it is the most prominent problem in the welding of Al alloy thin wall structure. The physical model of ultrasonic peening course will be established. The mathematic model of ultrasonic peening parameters (amplitude, peening pin diameter, moving velocity), material mechanical properties (yield stress and Young's modulus under high speed impacting condition) and peening pin velocity will be obtained to get the maximum peening pin velocity. Combining the experiment results and finite element analysis, the ultrasonic peening stress field evolution based on the welding stress and deformations will be found to reveal the ultrasonic peening controlling welding residual stress mechanism. Based on the above results, the ultrasonic peening parameters and peening region can be determined. The relation of ultrasonic peening processing paramet

英文关键词： Ultrasonic peening；Constitutive relationship；Impact speed；Buckling distortion；Residual stress