8
votes
Accepted
What filter is this?
It might be written that way because the transfer function of a second order system is written as:
$$
h(s) = \frac{\omega_n^2}{s^2 + 2\zeta \omega_n s + \omega_n^2}
$$
where $\zeta$ is the relative ...
- 596
5
votes
Accepted
Where does weight mass conversion ratio '0.00259' come from in Nastran?
It's the inverse of the acceleration of gravity g in imperial units.
$$
1 g = 386.1 in/s^2
$$
$$
1/g = 0.00259 s^2/in
$$
You need that since:
$$
weight = mass * g
$$
- 176
4
votes
Is there any aspect of an Explosion resulting from a nuclear weapon test that cannot be simulated using super computers?
The type of machine that runs the simulation (e.g. super computer, slide rule, pen and paper, etc.) is less important than the physical and mathematical models that describe the process being ...
- 3,044
4
votes
How much force can a pole in ground take before falling?
this is a typical engineering problem and has an equation approved by IBC numbered 18-1.
$$d = 0.5 A{1 + [1 + (4.36h/A)]1/2}$$
The calculation process is I first calculate A =2.3* post load/(allowed ...
- 22.1k
4
votes
How to convert Joules(kinetic energy) plot chart into watts?
To convert a plot of J versus s to a plot of J/s vs s, take the derivative.
Here is my quick-and-dirty answer after digitizing the data.
- 2,878
3
votes
How to implement a Monte Carlo Simulation for studying uncertainty in dynamic stiffness?
My advice would be to forget about the mathematical theory and start thinking about what the engineering means. It's hard to think of any situation where the stiffness of a sensibly designed structure ...
- 12.5k
3
votes
Accepted
Non-Clutch Vehicle Drivetrain - How Does it Work?
Conventional automatic transmissions have a torque converter which uses a viscous rather than a rigid coupling to connect input and output. This performs a similar function to a friction clutch but ...
- 15.2k
3
votes
Is there any aspect of an Explosion resulting from a nuclear weapon test that cannot be simulated using super computers?
The accuracy of a simulation depends more on how well your equations and assumptions model reality, than the resolution of the simulation (computing power, as Carlton has stated). More computing power ...
- 7,904
3
votes
Accepted
ANSYS Workbench/Mechanical: Automatically export chart?
There are several options for doing this:
If there are only a few values to be saved per design point, you could use 'output parameters'.
If there is a lot of data to be saved, the report generator ...
- 156
3
votes
How to determine time taken for tyre to deflate using CFD analysis?
I don't think CFD is the right tool. You can use an orifice equation, say from ASME, to calculate flow rate from inner and outer pressure. This takes the form of:
$$\dot{m}=\frac{EC_D}{\sqrt{1-\beta^4}...
- 821
2
votes
SolidWorks circuit simulation?
CircuitWorks doesn't simulate the electronics; it just integrates between some common PCB design software formats and SolidWorks for mechanical information. For example, maximum component height, ...
- 328
2
votes
How can I save mass, inertia, joint location and part orientation data from any 3D-CAD program to a CAD file?
This sounds like the exact synopsis of my masters thesis.
Theoretically a format that can contain this info exits. STEP could include this information, but since the exporter has some serious leeway ...
- 3,597
2
votes
Automotive Radiator Simulation
Either your definition of "completely" is a bit unusual, or there's something wrong with those charts, because in those charts, 1.6 x the model does not completely match any of the six observations ...
- 3,751
2
votes
Component-based simulation versus block-based simulation
Components have connections that can be either inputs or outputs, while blocks have defined inputs and defined outputs.
With the components you can have bidirectional causality while if you want to ...
- 1,335
2
votes
Accepted
How much force can a pole in ground take before falling?
Depending on the kind of engineer you ask you will get many different options to approach this - your question is pretty open-ended. As a Geotechnical Engineer I'd say your pole can be looked at as a ...
- 36
2
votes
Simulation of motion, collision, friction and thermal expansion in 3D
This is a multi-physics analysis, there are some open source packages though i'm not familiar with them (OpenFOAM is open source CFD software, and COMSOL is example of an commercial multi-physics ...
- 632
2
votes
Accepted
LS DYNA Material Model 163, Modified Crushable Foam
While the yield stress is a well defined point in materials such as steel or other metals, that is not the case when we talk about foams.
Here they are calling "yield stress" to the whole volumetric ...
- 86
2
votes
How should the assignment to test software for a vehicle’s VCU be aproached?
I am not too familiar with the VCU, PV780, or PowerVision. Based on your description PV780 can be configured to be the Instrument Cluster Panel (ICP) for Engine Control Unit/Module (ECM) or ...
- 7,125
2
votes
How can I validate the validity of a model of a dynamical system?
Verify your model against actual physical hardware. If you're sure of parts of the model, and unsure of others, then just verify the parts you're worried about. If the physical hardware is big and ...
- 2,472
2
votes
Accepted
Calculating final drive force from engine torque and tyre spin ratio
You need to convert the torque at the axle into force against the ground through the tire (Force = torque/radius). Then F=ma for the entire mass of the car (plus if you want to be precise the ...
- 6,544
2
votes
Accepted
Is a MSC Adams simulation with smaller steps always more reliable?
This is a common issue on all numerical methods (not just multibody problems), i.e. the tradeoff between the following three types of error:
Round off error
Discretization
Truncation (sometimes the 2 ...
- 24.3k
2
votes
Simulation of RC circuit using Proteus
Try using a replacing a 9V VDC voltage source with a VAC voltage source. Pay attention to the frequency of the VAC voltage source. This should address the issue.
With regard to determining the time ...
- 7,125
2
votes
What meaning does the following sine wave have when it comes to amplitude?
It means that there is a positive offset of one. So your signal is
$$ x(t) = 1 + 2 \cdot \sin(\omega t)$$
where:
1 is the offset
2 is the amplitude of your signal (not 4).
- 24.3k
2
votes
Accepted
Modeling a simple capacitor
Capacitance only depends on its geometry, ...
False. Capacitance is also determined by the dielectric (the insulator) between the plates and this can have a huge effect on the value obtained.
... ...
- 10.4k
2
votes
Non-Linear Analysis Convergence Problem in Ansys
Your model contains a lot of nonlinearities, therefore achieving convergence is not easy. I would try gradually adding each nonlinearity to narrow down where the solver is struggling:
turn off large ...
- 75
2
votes
Simulating production of a product by a machine
A single machine with no input constraints can be modeled as an average.
First of all, if you're going to model manufacturing, model shifts that make sense to people in manufacturing. Shifts in ...
- 6,544
1
vote
Software options for simulating oil flow in small diameter pipes
Pipe-flo is a good commercial tool for what you describe.
https://eng-software.com/products/pipe-flo/
- 121
1
vote
Software options for simulating oil flow in small diameter pipes
As far as I understand any CFD package worth its name can model fluid flow - you just have to specify the fluid characteristics for that fluid.
As for size, that should not be an issue - some ...
- 15.5k
1
vote
Accepted
Suppliers who write dynamical specification inside their data sheet?
The dynamics you’re looking for are largely governed by how you connect the different components in your design. Although the hydraulic pump you select is important, the equations provided in the ...
- 540
1
vote
Simulate Dust Layer on PV Cell?
More to the "even-distribution" question, I'd recommend your idea of water distribution. I'd use spray nozzles - they're designed for relatively even distribution. To that end, I'd recommend IS ...
- 5,343
Only top scored, non community-wiki answers of a minimum length are eligible