目的 为克服激光冲击强化现有离线检测方法的缺点，提出了一种基于空气中冲击波信号能量的激光冲击强化在线检测方法。方法 利用波长为1064 nm、脉宽为14 ns、单脉冲能量为5~7 J的Nd:YAG激光器对经过振动时效处理的TC16钛合金试件进行激光冲击强化处理。用自主研制的信号放大器对空气中的冲击波信号进行一级放大后，再经前置放大器、数据采集卡传输到计算机控制系统，从而实现对空气中冲击波信号的采样、存储、滤波和数据分析，并从中提取冲击波信号能量。用X-350A型X射线应力测定仪测量TC16钛合金试件经激光冲击强化处理后的表面残余应力。最后对所得实验数据进行多项式拟合，以获得材料表面残余压应力与冲击波信号能量之间的经验公式。结果 经激光冲击强化处理后，材料表面形成了一定大小的残余压应力。随着激光能量的增加，材料表面残余压应力及冲击波信号能量均增加，且二者的增加趋势一致。结论 在激光冲击强化过程中，对空气中传播的冲击波信号进行采集和提取其信号能量，可以预测试件经激光冲击强化处理后的残余应力，能够准确判断激光冲击强化质量，从而实现工业过程的在线检测。

The work aims to propose an online detection method of laser shock peening based on shock wave signal energy in air to overcome the existing disadvantages of offline laser shock peening detection methods. The TC16 titanium alloy samples after the treatment of vibration stress relief were treated by Nd:YAG laser with a wavelength of 1064 nm, pulse width of 14 ns and pulse energy of 5~7 J. The shock wave signals in air were first amplified by the signal amplifier that independently developed by our research group, then transmitted to the computer control system through the preamplifier and the data acquisition card successively. So the sampling, storage, filtering and data analysis of shock wave signals in air were realized, then the shock wave signal energy was extracted. The surface residual stress of TC16 titanium alloy samples after the treatment of laser shock peening were measured by the X-350A X-ray stress tester. Finally, according to the obtained experimental data, an empirical formula between the surface residual stress of the material and the shock wave signal energy was obtained by polynomial fitting. The experimental results shown that after treatment of laser shock peening, there are a certain amount of residual compressive stress was formed on the surface of the material. At the same time, both the surface residual stress and shock wave signal energy were increased with the increases of laser energy, and their growth trends are consistent. In conclusion, during the process of laser shock peening, by collecting the shock wave signals propagating in air and extracting the shock wave signal energy, the residual stress of materials can be predicted and the quality of laser shock peening can be judged accurately, which will realize the online control of industrial process.