Laser Phase Array Generation of Ultrasound for On-Line Weld Quality Control

本研究的目的是开发一种新颖、高效的 非接触式激光相控阵技术 超声波，用于固体的无损评价（NDE）， 流程. 这项新技术使用一组激光束 一个单一的梁。 这项研究将包括一项基础研究， 评估性能并建立分析模型， 相控阵 在线非接触无损检测的具体应用 在气体冶金过程中控制渗透深度和孔隙率 电弧焊（GMAW）工艺将继续进行。 电磁 声换能器将用作非接触式接收器。 的 研究分为五个阶段：（1）开发 用于预测超声产生的分析模型， 激光相控阵;（2）实验验证模型， 相控阵技术在非接触式天线中的应用 焊接熔深的无损检测在线控制 孔隙度;（4）发展传播的分析模型 通过焊接池的声音;和（5）数据的发展 采集系统和算法。 焊接熔池信息 从超声波信号中提取的渗透率和孔隙率将 用于焊接电源的系统反馈， 电流或速度控制，以实现所需的渗透， 孔隙率

The purpose of this research is to develop a novel, efficient technique of noncontacting laser phased array generation of ultrasound, for the nondestructive evaluation (NDE) of solids and processes. The new technique uses an array of laser beams in place of a single beam. The research will include a basic study to evaluate the performance of and develop an analytical model for the phased array. Specific applications to noncontact NDE on-line control of the depth of penetration and porosity during a gas metal arc welding (GMAW) process will be pursued. An electromagnetic acoustic transducer will be used as a noncontact receiver. The research has five phases as follows: (1) development of an analytical model for predicting the generation of ultrasound by a laser phased array; (2) experimental verification of the model for the phased array; (3) application of phased array to noncontact NDE on-line control of the depth of weld pool penetration and porosity; (4) development of an analytical model for propagation of sound through the weld pool; and (5) development of the data acquisition system and algorithms. The information on weld pool penetration and porosity extracted from the ultrasonic signal will be used in the system feedback for the welding power-supply, current, or speed control, to achieve the desired penetration and porosity.