1984 Volume 2 Issue 2 Pages 259-264
Real-time measurement of the current ptah area in spot weld by the resistance between electrode tips can be applicable to the welds at the early period of weld time, introducing a new parameter of effective time-integral value of the voltage between electrode tips in the case of mild steel sheet of 0.8-3.2 mm thickness.
The current path area in spot weld is related to the resistance between electrode tips, current path length and average resistivity, which is a function of material compositions and average temperature at the current path part in spot weld, based on Ohm's law. In above factors, the current path length is nearly constant in the case of no splashing, and furthermore, average temperature at current path part can be estimated from effective integral value of the voltage. So, average resistivity is determined only by effective integral value of the voltage. As the result, the current path area can be measured by both the resistance and the effective integral value of the voltage at any period of weld time under certain welding conditions with no splashing.
Furthermore, the new real-time measurement of current path area by the resistance and the effective integral value of the voltage can be adapted to the spot welds with various thickness of 0.8-3.2 mm at any period of weld time under certain welding conditions of no splashing.