Recent content by davidm1732

Acoustic pressure is dynamic, so you are measuring a pressure perturbation (variation). Think of a DC signal vs an AC signal. The acoustic pressure would be a (usually) very small AC pressure signal. It would be measured on top of any existing static or dynamic pressure variation present...

I'm assuming you're using accelerometers that can measure down to dc? If they're piezo based sensors, they're designed for ac signals, so won't respond well to the relatively constant type accelerations you're discussing here. You'd need an oscillating acceleration... rotating imbalance, a...

I'm not sure your request for a "dumbed down" version, without equations was fully met! SophieCentaur had a good illustration with the sheet of paper example. Another classic example is to fold a sheet into a pleated pattern. The sheet can now hold up weight, where the flat sheet was...

Hi, 1. More or less... 20uPa is generally accepted as the threshold of hearing, so given that, 0 dB would be the lower limit for hearing...but it varies from person to person... age, exposure, etc... depends how picky you need to be with the application of that concept 2. I think that...

The units are acoustic decibels (dB). The reference value for the dB ratio shown is 20 micropascals..the standard reference for sound pressure level. When you ask the analyser display the units in the dB scale, you usually have to define the reference level it uses to perform the dB...

I'm a mechanical engineer in the automotive industry, and specialize in noise & vibration. I do both hands on measurement and computer simulation work. Lots of problem solving and conceptual work, so it's pretty good. I have mechanical engineers who sit across the aisle who have a lot of...

The rubber compound is softer and stickier in racing tires (I'm in North America!), and can't handle the higher internal pressure that a street tire would, so to support the vehicle, you need to have a larger contact patch, and hence wider tires. Take the surface contact patch area and...

Wow...that's a lot to digest... I've only skimmed it but here are a few comments... To understand order content... think of the pulses coming from each exhaust valve. If all pipes are same diameter and same length, the pulses all line up evenly distributed & sequential at the termination...

My initial thought after seeing the print add for it was that it was a tuned mass damper type of device. Then I read the link to the ISVR paper, and that also provides more detail on that type of device. I don't think it's a helmholtz resonator... that's an acoustic device consisting of a...

Ouch... If you don't have access to the full stress/strain curve for your material, see if you can download the CAMPUS database...it has material data from a number of polymer suppliers, for many of their specific resin types, and will have full stress /strain curves. If I understand where...

As an extension to what phinds said... The sound is the vibration of the air. The vibrating air is in contact with the wall, and transfers some of that energy to the wall. Now the wall is vibrating. The vibrating wall transfers some energy to the air inside the office. Now the air inside...

I think Studiot and Bobbywhy are approaching this problem using somewhat different methodologies... Bobbywhy is suggesting a cavity resonator. The source signal would excite the acoustic cavity at it's resonant frequency, and you'd see high internal acoustic pressures in the cavity at that...

How is your load applied...on the geometry or on the mesh? What is your mesh density in that area... do you have a fine enough mesh? If you've applied the load on the geometry (surface), and you have a very coarse mesh, you may have issues. What pre-processor & code are you using... some...

Do a quick search on inertial vs non-inertial frames of reference for more information on this. To clarify, your example holds true if the boat (or plane) is not accelerating. If it is traveling at constant velocity, and you drop the coin, it will appear to fall straight down... it really...

There's a device called a Frahm tachometer that I believe kind of works on a similar principle...it has a series of reeds each with a different resonant frequency. When exposed to a complex vibration signal, the reed vibration will indicate what tones are present in the signal. With your idea...