Specifying damping in Automotive materials !!!!

[Speedy]

This question is not work related.....here goes anyway;

To what extinct does the automotive industry desire materials to have good damping properties?

By 'materials' I mean those not diectly involved in suspension/shock absorbtion, materials such as the chasis, frame, internal trimmings, mountings etc. It seems to me that if all these materials had good damping, then they would contribute greatly to noise reduction.

If this is the case, how is damping specified? Speedy

"Tell a man there are 300 billion stars in the universe and he'll believe you. Tell him a bench has wet paint on it and he'll have to touch to be sure."

 

[GregLocock]

To some extent there is a benefit from using high damping steel in the body in white. This consists of a metal plastic metal sandwich. You can measure the damping in all sorts of ways, but the only way that matters is to measure the damping of the panel as installed in the vehicle.

This is typically done using a two channel FFT analyser, a hammer and an accelerometer.

As it turns out the benefits are not all that 'great'.

We also use stick-on bituminous pads for particular problems, which work well, but are very heavy and expensive. Cheers

Greg Locock