Measurement and Characterisation of a Diffuse Acoustic Field Using a Phased Array

• 作者: Jingwei Cheng
• 来源期刊: 中国机械工程学报
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: Intelligent Manufacturing Technology
• 页码范围: 262-270
• 页数: 9页
• 语种: 英文

摘要

A diffuse acoustic field has been increasingly used to infer temporal changes in the structures,such as early dislo-cations and microcracking.This study explores three different techniques to characterise acoustic field by using a single ultrasonic phased array.The first two techniques are proposed to measure spatial uniformity of wave field by examining differences in the integral of energy and the maximum energy respectively at multiple inspection loca-tions.The third one is developed to evaluate the degree of phase coherence between propagating waves transmitted sequentially by two neighbouring array elements.The efficacy of these techniques are investigated by examining their metrics on simulations and well-known samples.The results suggest that two selected metrics can be used to quantitatively estimate the diffuse field start time as well as the field size by comparing their value with the idealised diffuse state(15％for the energy integral metric,ηarea and 1 for the phase coherence metric,ηphase)and identifying the convergence start point.