Finite Element Simulations to Predict Probability of Detection (PoD) Curves for Ultrasonic Inspection of Nuclear Components
Finite Element Simulations to Predict Probability of Detection (PoD) Curves for Ultrasonic Inspection of Nuclear Components
复制标题
通过有限元模拟预测核部件超声波检测的检测概率 (PoD) 曲线
DOI：
10.1016/j.proeng.2014.11.059
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
T. Jayakumar
中科院分区：
文献类型：
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作者：
S. Subair;K. Balasubramaniam;P. Rajagopal;Anish Kumar;B. Rao;T. Jayakumar
核工业中用于结构鉴定的无损评估（NDE）方法要求达到非常高的可靠性标准，因此，建立检测技术的性能能力至关重要。一般来说，检测概率（PoD）曲线方法已成为评估无损检测技术性能的重要工具。然而，传统的生成PoD曲线的实验方法非常昂贵，需要大量的实验数据集，涵盖不同的缺陷，以及一系列的测试条件、工厂关闭和操作时间。为了解决这一问题，已经出现了几种使用基于物理的建模来更快估计PoD曲线的方法。然而，大多数理论模型仍然局限于少数材料或缺陷类型：因此数值建模技术非常有吸引力，特别是考虑到当今科学家可用的计算能力不断提高。本文报告了利用有限元模拟来增强实验稀疏测量的可行性，并预测了不锈钢板和焊缝超声检测的PoD曲线。对不锈钢板表面断裂纵向缺口进行常规（体P波和SV波）超声脉冲回波检测，得到了PoD曲线。确定了实际超声检测中影响不确定度的主要参数，并假设每个参数都按正态分布变化，实现了组合。对每种参数组合进行有限元模拟，即频率、楔形角、缺口尺寸，并使用预测的散射UT信号的振幅来生成PoD曲线。结果与试验测量结果进行了比较。讨论了奥氏体不锈钢厚焊缝超声检测中POD曲线的生成方法。
Nondestructive evaluation (NDE) methods for the qualification of structures in the nuclear industry are required to perform to very high standards of reliability, and hence, establishing the performance capabilities of inspection techniques is of utmost importance. The Probability of Detection (PoD) curve method has emerged as an important tool for the assessment of the performance of NDE techniques, in general. However, the conventional experimental means of generating PoD curves is very expensive, requiring large experimental data sets covering different defects as well as a range of test conditions, plant shut-down and also operator time. Several methods of achieving faster estimates for PoD curves using physics-based modelling have emerged to address this problem. However, most theoretical models remain limited to a small number of materials or defect types: thus numerical modelling techniques are very attractive, especially given the ever increasing computational power available to scientists today.This paper reports the feasibility of using Finite Element (FE) simulations to augment sparse measurements made using experiments, and predict PoD curves for ultrasonic inspection of stainless steel plates and welds. PoD curves are obtained for the case of conventional (bulk P and SV wave) ultrasonic pulse-echo inspection of surface-breaking longitudinal notches in Stainless Steel plates. The main parameters affecting the uncertainty in practical ultrasonic inspection are identified and combinations are achieved, assuming each of them varies according to a normal distribution. FE simulations are performed for each combination of parameters, viz. frequencies, wedge angles, notch dimensions, and the amplitudes of scattered UT signals so predicted are used to generate the PoD curves. The results are compared against trial experimental measurements. Approach towards generating the POD curves for ultrasonic inspection of thick austenitic stainless steel welds will be discussed.