Car body modification

[mrmartins]

Hi,

Anyone knows what type of tests are made over a car transformed into a cabriolet. I means tests to check if the structure, after cuts and strengthening, is able to withstand the efforts. Static and dynamic tests if they exist.

Thanks

 

[Hydroformer]

Testing would likely start with NVH (natural vehicle harmonics) longitudinal and torsional, using the unmodified vehicle as a benchmark.

*Without data, you're just another person with an opinion.*

Hydroformer

 

[GregLocock]

Static torsion and bending are the obvious place to start. In an ideal world you'd do a modal analysis as Hydroformer suggests, but you know its going to be awful, do you really want to know how awful? (for instance a Porsche 911 soft top from 1983 had a 12 Hz torsion mode). We mentioned this to a Porsche engineer, he said , ah, they are just girl's cars! For a production car you do need to know how awful it is. Typically the shake problems used to be so bad that desperate expedients were used - at least one BMW had a 20 kg slug of cast iron bolted into it to control shake. I've often had to retune engine mounts and so on.

Then you'd do durability.

There's also functional things like water leaks, soft top durability, vision, etc etc.



Cheers

Greg Locock

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