Inverse Problem Solution to Find Real‐Time Temperature Distribution Inside the Spot Weld Medium Using Ultrasound Time of Flight Methods

The scope of this paper is to find temperature distributions in the spot weld at different stages of welding using ultrasonic through transmitted waves. The finite difference modeling provides the temperature distributions in the spot weld. For the given welding schedule the delay of the signal passing through the heated area is unique for every temperature distribution. Based on the experimentally obtained TOF curve it is possible to determine the temperature at any point of the weld.