Best way to determine the impact Force is to simulate the transient event. The impact force is dependent on the energy and the stiffness of the to components.
It is true that the lower the stiffness the lower the impact force, but this also increase the deflection. So to calculate the stress...
Ok yes, I have proven this with a distributed Beam model subjected to different impact profiles.
So if your noise is emitted from for example 1-5kHz you need to prolong the impact event enough (by lowering the stiffness enough) to not excite these modes and frequencies on the structure.
Now I...
I can see how that easily works out mathematically.
So, the extra work done by the external force (energy) does not contribute to the vibratory response in any way in a linear system.
If it is nonlinear and has a "hardening" spring - I suspect the energy added cannot be ignored and would add...
Thanks gents.
Now if you had a force acting on the "hammer" during the impact (in the direction of impact), how would this effect the vibration response of the structure? Is there an analytical solution to this?
Thanks Greg. I understand the DC offset portion. What I am after is how the non-DC component (or vibration) changes with different impact duration and power.
I know that traditional impluse theory predicts that the impluse response is simple the same as free response for discrete systems - but...
Hello Gents,
Been a while since I posted here or commented. Good to see this useful set of minds is still very active.
I have a general questions I'd like to discuss and get some thoughts on.
Say I have a mass or inertia and it is being propelled by external forces. Then, it...
We also have the option to obtain a standing desk upon request. I have so far opted out.
What do you guys think about places moving to an "open concept"? We have been considering it and there are many mixed feelings about how it might go.
I agree with above.
BALLS will get you many places in this world. If I were you I would confront head on (professionally) what you are experiencing.
Just be honest and objectively outline your concerns and relate them to company objectives etc. if possible.
Agree with both of the above.
But, you can include stackups (or statistical analysis methods) into analyzing motions. This is design for six sigma (DFSS).
For example, you can start with your basic force to displacement relations in your system and "bake in" the statistical variances in the...
Are you looking for analytical solution or numerical? I suggest numerical - the solution is pretty easy and the setup depends mostly on how you want to numerically solve it.
Rod,
What is your idea? I'd be interested in taking a look at your patents.
I agree, in general the enabler for many e-machines long term is only energy density (sounds simple, but isn't however).
Interesting. I noticed it has: Interface with MATLAB (Chrono::Matlab)
Cosimulation with Simulink (Chrono::Cosimulation)
I wonder how this works exactly? And what the use cases might be.
Hi Greg,
Another question comes to mind when looking at TVDs.
If I put a certain amount of energy (from combustion) into the crankshaft and it vibrates torsionally at a certain speed there will be a certain energy associated with this vibration. If we now put a TVD (not has less vibration at...
Tunalover,
These algebraic manipulation programs(software) exist. My favorite a few years ago was Maple (https://www.maplesoft.com/products/Maple/academic/). It is still the best IMO.
Here are 2 screen shots of one of my worksheets...
Indeed the solution in Inman's text doesn't show the whole derivation in the manner shown in that link. It does refer to the method of undetermined coefficients- which is just an algebraic solution method.
I took a few pics since it seems it may be of interest...
There is an analytical solution to this. I derived one many years back. I can check my notes. This is a traditional base excitation problem. Solution will be in obtained by taking the Laplace and solving for abs magnitude of |Z/Y|.
Quick google search turn up similar problems...
hmm. Thanks again Greg.
The viscous dampers seem to just add damping across the board and are maybe only on engines that are highly dynamic. Not sure how true this is nowadays.
