Automotive equipment sine wave vibration test condition - BMW requirement?

[tomccchang]

Dear all,

Any one knows if automotive system would use the condition - sine wave 5-55Hz, amplitude 0.75mm for vibration test, in stead of random wave 10Hz-1000Hz, ASD 2G2/Hz. I was told the sine wave condition is from BMW spec, but my searches on internet saying that sine wave test is mainly for RD study purpose, and 5-55Hz/0.38mm is mainly used for IT industry.

[Marc]

Anyone have any information on this? I know it's an old post, but what the heck.

[Jim Wynne]

When vibration testing is required, a standard is always referenced. You have to use the test conditions specified in the standard. If the OP is related to a specific customer requirement, it will be best to ask the customer what's expected. Perhaps some more detail about the reason for the question would help us to give some guidance.

[tomccchang]

Thanks Jim, the issue I have had is we are given swept sine spec to meet but we can not pass the condition because of DVD and are told the spec used is not for automotive but for IT. We therefore discussed with the customer and at the end we were asked to raise the ramdon vibration proposal and to translate swept sine to ramdon. There are some ways to translate the spec, but as far as I know, both methods are not comparable. This have developed a disaster as we have a number of additional experiments to run. So, I have been thinking if we have been wrong asking the cutomer to change swept sine to ramdon if BMW has used swept sine vibration test condition. I am just told Ford uses swpt sine condition.

Tom

[Jim Wynne]

Originally Posted by tomccchang

Thanks Jim, the issue I have had is we are given swept sine spec to meet but we can not pass the condition because of DVD and are told the spec used is not for automotive but for IT. We therefore discussed with the customer and at the end we were asked to raise the ramdon vibration proposal and to translate swept sine to ramdon. There are some ways to translate the spec, but as far as I know, both methods are not comparable. This have developed a disaster as we have a number of additional experiments to run. So, I have been thinking if we have been wrong asking the cutomer to change swept sine to ramdon if BMW has used swept sine vibration test condition. I am just told Ford uses swpt sine condition.

Tom

I understand (and empathize with) your predicament; having a customer who doesn't know what he wants but wants you to provide it anyway, is not fun. You and the customer will not accomplish anything meaningful if you can't develop test methods that simulate (and perhaps accelerate) what the assembly will be subjected to in end use. Thus if you have a menu of various vibration testing standards, selecting one because someone else uses it will only help you to verify that you're performing the same testing as someone else. If you settle on standard X and the customer agrees to it, and your parts pass the testing, you've gotten yourself off the hook without solving the problem.

This is a matter for the customer's design engineers to settle. The best way to approach this, imo, is to politely tell the customer that while you are happy to assist in any way you can with making a quality product, you can't be held responsible for the design intent of the system.