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激光冲击成形的重要特点之一就是能在工件表面形成残余压应力,起到强化的作用,对具有抗疲劳性能要求的航空结构件有重要意义。本文对激光冲击成形的3A 21防锈铝板的残余应力分布特性进行了研究。用X射线应力测定仪进行了三个方向残余应力的测量,建立了主应力计算公式,分析其形成机制与分布特性。试验结果表明:在脉冲能量42 J、脉冲宽度23 ns、脉冲功率1.2×109W作用下,板料正反两面产生的残余应力小于-100M Pa,且均为压应力,除变形区域顶点主应力方向为0°外,其他点的主应力方向约为-30,°且正方形板料对角线方向应力大于穿过中心边长方向的应力。
One of the important features of laser impact forming is to form residual compressive stress on the surface of the workpiece, which plays a strengthening role and is of great significance to aviation structural components that have the requirements of anti-fatigue performance. In this paper, laser shock forming 3A 21 rust proof aluminum plate residual stress distribution characteristics were studied. The X-ray stress analyzer was used to measure the residual stress in three directions. The formula of principal stress was established and its formation mechanism and distribution characteristics were analyzed. The experimental results show that the residual stress generated on the front and back of the sheet is less than -100 MPa under the pulse energy of 42 J, the pulse width of 23 ns and the pulse power of 1.2 × 109 W, and are all compressive stress except for the principal stress direction Is 0 °, the principal stress direction at other points is about -30 ° and the diagonal direction stress of the square sheet is larger than the stress of the longitudinal direction of the central edge.