相控阵虚拟探头阵元数量与聚焦深度的试验分析

Analysis of the Quantity and Focus Depth of Phased Array Virtual Probe Element

通过调整相控探伤仪阵元数、起始阵元和末阵元的方式,组成不同阵元数的虛拟探头,利用RB-1超声探伤标准试块,在H=25 mm的底面回波条件下,记录了不同聚焦深度下,底面回波达到80%波高情况下的增益值,分析不同聚焦深度下,不同虚拟探头阵元数与其增益值的变化趋势,并通过建立相应的数学模型,解释了不同阵元数虚拟探头声压在不同聚焦深度下变化的原因,总结出相控阵超声检测在实际应用中,应该遵循的聚焦深度和虚拟探头阵元数选择的一般规律。

By adjusting the quantity of phased array element and the arrangement of initial array element and final array element to form a virtual probe with different quantity of array element,and by using RB-1 standard test block for ultrasonic detection,this paper records the gain values when the bottom echo reaches 80%of the wave height at different depth of focusing under the condition of bottom echo H=25 mm,analyzes the variation tendency of different virtual probe array element quantity and their gain values at different depth of focusing,explains the reasons for the change of sound pressure of virtual probe with different quantity of array element at different depth of focusing via establishing a corresponding mathematical model f and summarizes the general rules for the selection of depth of focusing and array element quantity for virtual probe in practical application of phased array ultrasonic detection.