Slongo Juliano Scholz, Gund Jefferson, Passarin Thiago Alberto Rigo, Pipa Daniel Rodrigues, Ramos Júlio Endress, Arruda Lucia Valeria, Junior Flávio Neves
Graduate School on Electrical Engineering and Applied Computer Science, Federal University of Technology-Paraná, Curitiba 80230-901, Brazil.
Centro de Pesquisas, Desenvolvimento e Inovação Leopoldo Américo Miguez de Mello-CENPES/PETROBRAS, Rio de Janeiro 21941-915, Brazil.
Sensors (Basel). 2022 Apr 6;22(7):2799. doi: 10.3390/s22072799.
Ultrasonic inspection techniques and non-destructive tests are widely applied in evaluating products and equipment in the oil, petrochemical, steel, naval, and energy industries. These methods are well established and efficient for inspection procedures at room temperature. However, errors can be observed in the positioning and sizing of the flaws when such techniques are used during inspection procedures under high working temperatures. In such situations, the temperature gradients generate acoustic anisotropy and consequently distortion of the ultrasonic beams. Failure to consider such distortions in ultrasonic signals can result, in extreme situations, in mistaken decision making by inspectors and professionals responsible for guaranteeing product quality or the integrity of the evaluated equipment. In this scenario, this work presents a mathematical tool capable of mitigating positioning errors through the correction of focal laws. For the development of the tool, ray tracing concepts are used, as well as a model of heat propagation in solids and an experimentally defined linear approximation of dependence between sound speed and temperature. Using the focal law correction tool, the relative firing delays of the active elements are calculated considering the temperature gradients along the sonic path, and the results demonstrate a reduction of more than 68% in the error of flaw positioning.
超声检测技术和无损检测在石油、石化、钢铁、海军和能源行业的产品和设备评估中得到广泛应用。这些方法在室温下的检测程序中已成熟且高效。然而，在高温工作条件下的检测过程中使用此类技术时，在缺陷的定位和尺寸测量方面会出现误差。在这种情况下，温度梯度会产生声学各向异性，进而导致超声束畸变。在极端情况下，如果在超声信号中未考虑此类畸变，可能会导致负责保证产品质量或评估设备完整性的检查员和专业人员做出错误决策。在这种情况下，本文提出了一种数学工具，能够通过校正聚焦法则来减轻定位误差。为了开发该工具，使用了射线追踪概念，以及固体中的热传播模型和通过实验确定的声速与温度之间依赖关系的线性近似。使用聚焦法则校正工具，考虑沿声路径的温度梯度计算有源元件的相对发射延迟，结果表明缺陷定位误差减少了68%以上。
