Resistance changes due to current cycling

[viscaritatis]

I'm just brainstorming here, really.

How might resistance change across a sample of metal due merely to the cycling of current across it?

This type of cycling happens in electric cars each time the car is turned off and on, and this is exactly the application I'm thinking about.

Here's what I was thinking:

The effect of the current by itself will likely be unapparent over a car's standard design life-time (say, 250,000 miles), but the electroplastic effect combined with the effects of alternating loads (i.e. the car shaking up and down due to bumps in the road) will cause certain joints in the electrical system's high-amperage parts to experience increases in resistance over the life of the car.

The alternating loads by themselves would, of course, cause increased resistance due to the microstructural effects of fatigue, but I have a feeling that the effect would be compounded via the electrical current.

All of this ties back to the efficiency of the car's battery, which would of course decrease over time if the power loss due to the resistance of it's internal circuitry increased over time.

Anyone else have other angles from which to approach this?

 

[Achy47]

I find your brainstorming very interesting and thought-provoking. Resistance is an important factor to consider in the design and operation of electric cars, as it directly affects the efficiency and performance of the vehicle. Your idea of the electroplastic effect and the effects of alternating loads on resistance is definitely worth exploring further.

One potential angle to consider is the effect of temperature on resistance. As the car is driven and the electrical system is used, it will generate heat. This heat can cause the metal components to expand and contract, potentially altering the resistance of the system. This could be especially significant in high-amperage parts, as you mentioned, where the current flow is already high and any changes in resistance could have a larger impact.

Another angle to consider is the type of metal used in the electrical system. Different metals have different resistivity values, so the choice of metal could also affect the resistance and overall efficiency of the system. Additionally, the metal's microstructure and grain orientation could also play a role in resistance changes over time.

Overall, I think your idea of the combined effects of the electroplastic effect and alternating loads on resistance is a promising area of research. It would be interesting to conduct experiments or simulations to better understand the specific mechanisms at play and how they might impact the efficiency of electric cars over their lifetime. Thank you for sharing your thoughts and opening up this discussion.