Automatic Diagnostic of Resistance Spot Welds Using Adaptive Ultrasonic Phased Array Method
Is Version Of
Begun in 1973, the Review of Progress in Quantitative Nondestructive Evaluation (QNDE) is the premier international NDE meeting designed to provide an interface between research and early engineering through the presentation of current ideas and results focused on facilitating a rapid transfer to engineering development.
This site provides free, public access to papers presented at the annual QNDE conference between 1983 and 1999, and abstracts for papers presented at the conference since 2001.
This paper presents the results of a collaborative research program related to an efficient inspection procedure dedicated to characterizing and sizing resistance spot welds. This method allows to perform a real-time diagnostic of the resistance spot weld according to the following categories: good/stick/small/excessive indentation. The method is based on the combination of a highly resolved ultrasonic cross-section image thanks to real-time Adaptive phased array Total Focusing Method, with a dedicated decision making process. A specific phased array-probes with a flexible membrane with water coupling is placed over the spot weld, and the ATFM technique automatically measures the exact, uneven shape of the part and provides an accurate TFM image of the cross-section of the weld (see Figure 1). This image is automatically processed and analyzed. These algorithms have been implemented in portable phased-array ultrasonic system (Gekko, by M2M), and experimental tests over a large series of good and bad samples have been carried out (by Renault), to evaluate the performances of this method. The principle and implementation of the method, as well as examples of images and diagnostics associated to various samples will be discussed in this paper.