Has anybody tried using carbon fiber as a fixture material? Here in the vibration lab, we were brainstorming about alternative fixtures for our products and an outside the box suggestion of carbon fiber came up. We're thinking why not? A foam core would be great for vibration damping, the...
We run aerospace parts ranging in size from baseball size up to 1000 pound engines on our shakers. Some customers want to do a bare fixture evaluation and some don't. I've heard some reasons to do it and some reasons for why it's a waste of time but I haven't been able to really delve into it...
What do the terms "resonance dwell" mean to you? Does it mean tracking dwell or fixed freqency dwell?
Or is it more of a general term that further needs to be defined by "track" or "fixed"?
Maybe I missed this in the search, but I didn't see this topic posted before...
Recently, one of the grey beards (or mustache in this case) said to always put a washer on a bolt a certain way. The washers are stamped so often times there is a curve or bow to them and they also have a slight...
I've been told that at low frequencies, <3ish Hz, that the motion of the whole airbag supported shaker subtracts from the motion of the unit under test, but I'm having a hard time wrapping my head around it.
For example, when we ran a dwell at 2 Hz the whole shaker moved, about 1/2", roughly...
If a machine shop completely blows by their quote for a widget, would you as the customer, pay the additional amount? I'm leaving this rather open ended for now, to see what the concensus is. I'll fill in the details later.
I'm not sure if this is a new policy or it has always been like this, but I've learned that my company has a policy where one cannot get promoted in place. That is, in order to be promoted, a job position has to be opened and I would have to interview for it along with everybody else. This...
Do keenserts hold up to this test if the parent material (fixture) is aluminum? The part we're testing weighs about 50-100 pounds and there will be 26 bolts/keenserts. The keenserts will be approximately 1 inch in OD.
I'm concerned the keenserts will work themselves loose from the aluminum.
What kind of adhesive do I use to glue a viton Fluoroelastomer seal to stainless steel?
We're making a thermal chamber door and we cannot use any silicone so RTV is out. Temperatures range from -80F to +250F. Air pressure is room pressure.
This is the seal we're using...
We're having a thermal chamber extension built in-house and have found a problem with the expanding foam that was recommended to us.
The thermal analysis that was done suggests polyurethane foam (0.014 Btu/hr-ft-F) or cork board (0.025 Btu/hr-ft-F)for the insulation. The expanding foam that...
One of our programs has money to burn and would like to buy our lab a video camera to capture motion during our vibe tests. Currently, we are using an old digital still camera to take short clips of motion while using a strobe light. This arrangement works OK and does show motion, but has it's...
We have a requirement to run some vibration tests at very low frequency and very high displacements and we are having difficulty finding a U.S. test house that can accomodate it.
The requirement is approximately 11 inches of displacement at around 2 Hz. We've looked at the usual suspects...
I'm having a hard time wrapping my head around the concept of a primary positive and negative SRS responses. What is physically happening to produce these waveforms? How are they derived?
Why do manufacturers use drum brakes on passenger cars/trucks rather than disk brakes? Because of their simplicity, it seems like disks would be cheaper to build plus they stop better. What advantage do they have over disks?
Anybody use vendors other than the OEM shaker companies to get little generic parts for your shakers? UD wants an arm and a leg for everything, plus they have a $75 handling fee for every order. Specifically, I'm looking for the rubber diaphragm used to keep debris out of the armature.
For those of you who use Spectral Dynamics for your vibration controllers, how do you manage your data? Once you have your response plots, etc, how do you send the data to your customers?
Currently, we are using a local server called Test Report Management (TRM) from Cabem Tech. This product...
Based on some searching I've done here I know that I should be joining professional societies and such, but on a more local level I like to go out to lunch with coworkers to network. The wife on the other hand thinks it's a waste of money and to a certain extent I agree. I certainly don't want...
Can somebody point me to literature showing the accuracy of using various mounting methods such as beeswax, dental cement, stud, cyanoacrolate, etc. I found one from endevco but there must be more out there. I'm probably not using the right search terms in google.
We need to build an impromptu temperature chamber for our shake table which goes up to approximately 350F. The size will only be about 30"x19"x17". Ideally, we'd like to use a rigid foam insulation like the type used for houses, but they only go up to about 250F.
Mcmaster has rigid...
