Patent ID: 6796182
Filing Date: 2004-09-28
Classification: G01N

Abstract:
A method for non-destructive testing of a weld joint of a bolt welded onto a contact area on a planar sheet metal using the stroke ignition method, whereby during the welding operation a weld pool having a modified material structure is formed beneath the contact area in the sheet metal, the method using directed ultrasonic signals and comprising the following steps:a) transmitting of ultrasonic signals into the sheet metal using a directed and obliquely transmitting ultrasonic transmitter positioned at a coupling-in point A located on the planar sheet; b) positioning an ultrasonic receiver at a coupling-out point B located on the planar sheet and receiving the ultrasonic signals transmitted through the sheet metal at the coupling-out point B, an acoustic path being formed between the coupling-in point A and the coupling-out point B; and c) positioning the acoustic path in the sheet metal between the coupling-in point A and the coupling-out point B so that the acoustic path passes a center of the contact area in a distance d from this center, d being smaller than the radius of an intact weld pool and bigger than the radius of a non-Intact weld pool, and d) detecting the intensity of the ultrasonic signals transmitted along the acoustic path from the coupling-in point A to the coupling-out point B.