Shader For Welding Simulation? (With References)

Hello everyone! Could you suggest an approach to create the same shader effect for welding seam simulation like on the attached images? The example application runs on iOS in AR smoothly, thus it should not be something computationally complex...

The screen capture can be found here: GD-Link

Please note that color is changed dynamically with time and the wave pattern that also appears dynamically.
Thanks!