Is floor pan considered?

[trainguy]

All,

I am a structural engineer primarily working on stress-skin structures - railcars, etc with a good knowledge of effective widths, stability etc.

Is a floor pan in an automobile considered structural? I have corrosion on a drivers side pan adjacent to what looks like a 4 x 4 cross-section sheet metal tube.

Is crashworthiness severely affected?

tg

 

[BrianPetersen]

Unibody, or separate frame and body? If you don't know, what year and model?

A significant rust hole in a floor, if that's the only rust spot (which is highly unlikely), is probably not going to lead to the car collapsing while driving down the road. I betcha if you start looking, you're going to find more rust.

It would be a safety inspection failure where I am.

 

[trainguy]

Corolla 2010 CE (Canada)

I was hoping the floor pan would be excluded from the cross-section, or that is is substantially thinner in original design than the adjacent beefy member, in the frontal impact case.

I am pretty sure there is no issue in normal service. I am certainly not expecting OEM crash performance.

It started at the drivers heel area, but I fear the whole pan has been wet a long time. No holes appear - a local mechanic did not highlight corrosion damage on visual inspection of the underside. No hammer was used...

tg

 

[BrianPetersen]

That's a pretty common spot for rust to start. Wet boots walking on salted parking lots drip salt water in and soak the carpet there if you don't use something like Weathertech winter mats (which are solid plastic and contain the muck inside them).

That alone shouldn't affect crash much, but eventually you'll have the Flintstones car, and that's a problem.

On a car worth fixing, you can pull up the carpet and cut out the hole and weld in a patch, and get a few more years out of it, but most of the time it's better to start planning for a new vehicle. If you pull up the carpet, you're probably going to find more rust.