Questions tagged [modeling]
Use this tag for questions about numerical or analytical modeling and simulation of engineered systems.
151
questions
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1answer
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Deriving equation of motion of a 1 degree of freedom system
Before solving this system, note that the rigid bars $\mathrm{\overline{OA}}$ and $\mathrm{\overline{OB}}$ are rotating about point $\mathrm{O}$, not their respective CGs. To account for this two ...
3
votes
0answers
21 views
Solidworks Loft error (guide curve not intersecting with profiles)
I am trying to add 'finger grooves' to my model of a brake lever and want to use a loft to do so. I have created (to my knowledge) all required sketches for the loft but SW gives me an error when ...
1
vote
1answer
35 views
Autodesk Inventor Make Holes on Different Edges Based on One Line
I need to invent a construction based on standard square tubes with holes placed in certain distance from each other and from ends of the tubes:
I also need to imagine the tube with holes as a ...
1
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0answers
18 views
Setup Invention Process in Engineering CAD Software
I need to develop a collapsible metal construction. I have a few specific prerequisites. Generally speaking, it will be something like a big construction toy, but not be a toy. It has the specific ...
2
votes
2answers
29 views
Force Transmission in Flexible Tools such as this tool
In general, I want understand how the Power transmission in flexible tools works such as this flexible pick up tool in this link: https://www.youtube.com/watch?v=TLbCatz4Pnkv=q9AkmsTNLkY . ...
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0answers
24 views
Superimposing a Vector Field onto a Toroid in Matlab
I am a systems and control PhD student in Aerospace Engineering. Currently, I am trying to create a wind shear model of a toroidal thermal "bubble" in Matlab similar to the one in this paper (shown ...
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45 views
Pspice ac sweep problem
I want to run an AC sweep from 1 Hz - 10 MHz and calculate the output of the circuit (the voltage on RL), however spice shows that my voltage is 0 in a lot of parts that it shouldn't. I believe the ...
1
vote
1answer
35 views
Help understanding this dimension sheet
I am trying to currently model a few parts for my custom 3D Printer. I have found some flanged lead screw nuts i'm going to use, but i'm having a hard time reading the dimension sheet. Specifically, ...
0
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1answer
42 views
Calculate forces/ torques on a parallel spring array
I am stuck on the calculation of forces on a certain system involving parallel springs.
The schematic of the system is as follows:
The lower plane is fixed and the upper plane movable. There is a ...
0
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0answers
4 views
Magnetization characteristics and static characteristics of SR motor from Ansys Maxwell. Part II
Continuing the topic:
Magnetization characteristics and static characteristics of SR motor from Ansys Maxwell
Are there any people in the community who are more or less familiar with Ansis Maxwell's ...
2
votes
1answer
109 views
linearizing a non linear state space equation
I have this 1-DOF helicopter simulator.
The motor's armature resistance is $R$, inductance $L$ and motor constant $K$ and reaction torque on the motor shaft is $Ļ$. $T$ is equal to $k_1w_2^2$ and $...
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0answers
28 views
Lagrangian of a piezoelectric material
I'm confused about the Lagrangian of a piezoelectric material. I've seen multiple sources which seem to contradict each other.
The way I personally approach the problem is the following ($\underline{...
2
votes
1answer
48 views
Modeling the torque of a real motor
I am trying to control a real inverted pendulum by means of a DC motor, for this I must model the torque of the motor, the work I've done in this direction is the following (which I believe is right):
...
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0answers
8 views
Increase in target emission rate (TER) when using a air source heat pump (ASHP) in standard assessment procedure (SAP) calculation
I am running a SAP calculation on a proposed building which will be utilising a 8.5 kW ASHP for space and water heating. I am also running a comparative analysis against a mains gas boiler to show the ...
2
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0answers
22 views
How does one calculate the principial component stresses in an ellipsoidal tank due to head pressure?
I have parameterized the following common bulkhead tank, which has cylindrical walls (easy enough) and ellipsoidal bulkheads. The upper tank is full of a fluid of density 800 kg/m^3 and the lower is ...
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0answers
22 views
Slow integration of system ODE under specific conditions in adsorption problem
I am trying to solve the system of ODEs below. I am applying the finite differences to z, so I get a system of ODE that I can solve with a solver like ode45.
The problem is that under the conditions ...
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0answers
22 views
Water distribution through N x Needle orifices
Consider a water distribution setup consisting of a feeder line blocked at one end but having 100 needle outlets all the same size. The feeder line cross sectional area is much greater than a needle ...
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0answers
16 views
Custom Models in Process Engineering
I'm using Aspen Custom Modeler to create a model to be used in Aspen Plus and Aspen Plus Dynamics, and I'm having trouble figuring out how to code the mass balance, energy balance, etc. I'm ...
2
votes
1answer
122 views
How to model Motor Windings in Solidworks?
I want to model a DC motor in order to eventually do some simulations (temperature/cooling related) and I'm wondering what is the best way to model the motor windings?
I've seen a few video's on how ...
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0answers
18 views
How do I correctly model this system of torsion springs?
I am currently designing a symmetric parallel mechanism that can be modeled as follows:
Here, $\tau^j$ denotes actuator moments and $k_i$ are torsion springs constants. For a specific point in the ...
-1
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1answer
76 views
How to obtain plant parametric model of given system?
Consider the system:
$$ y(s)=b\frac{e^{āsĻ}}{s+a}u(s) $$
where a,b are unknown, constant parameters and $\ Ļ>0 $ is an unknown delay constant. How can I obtain a plant parametric model for this ...
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0answers
13 views
how to get more number variance compared as the csv output file of two model stl files in Cloudcompare
we are using the CloudCompare for comparing two mouth STL model for Final doctoral theses, like works done in this paper(pdf) shown blow:
and the instruction said here:
so i have tried to insert the ...
2
votes
1answer
105 views
Modelling a refrigeration cycle in Excel
Is it possible to model a heat pump cycle without using tools like EES, but using Excel? I am considering to use Refprop application as an add-in in Excel, and model a heat pump cycle. Another ...
1
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0answers
16 views
Visualization/Verification software for interacting parts e.g. Gears etc
Not sure if there is any software that would model the movements of physical parts, or if even they can move with the given configurations ( software engineer background, no idea the lingo used here )....
1
vote
1answer
99 views
How to calculate initial concentration of first-order reaction in CSTR?
(This question comes from a Chemical Engineering background, but basic Math and Programming knowledge is also required. I hope it still falls in the scope of engineering.stackexchange.com If not, ...
1
vote
1answer
19 views
Overextending and cutting a coil spring
This is related to my recent question
Can I weaken a coil spring consisting of spring steel?. The answer here could create an additional answer there, but I do not expect that. The difference to that ...
0
votes
1answer
41 views
Modelling Soil in a Scale Model
I'm building a scale model for a proposed construction project.
Is it possible to simulate foundations operating in soil in a scale model? What do people typically use?
0
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0answers
37 views
Can Flowmaster be used to model an entire pipe run?
I just started using the Flowmaster program (ver 08.11.01.03 if relevant) to model a series of stormwater pipes which are almost certainly in a pressure flow situation based on a first round analysis ...
1
vote
3answers
52 views
Why do we get singularities in a solutions while modelling a physical systems?
I wonder why do we get some times singularities (position to be infinity or velocity to be infinity) in the solutions while modelling a real system and in spite of taking all real parameter values of ...
0
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0answers
68 views
Help with Engineering Mathematics, Struggling to determine coefficients using methods detailed in this research paper
I am struggling with a curve fitting calculation below. the part I am stuck with is arguably the simplest part, which is determining the coefficients $\\K_3$ and $\\K_4$. It seems like it should be ...
0
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1answer
62 views
ElectroMagnetic Pulling Force fdropoff with distance
I am looking make a quick and dirty test ring using an off the shelf electromagnet. My force needs are small, less than a pound but I need to do so in a non contact manner. I know these magnets are ...
0
votes
1answer
21 views
How can I validate the validity of a model of a dynamical system?
I derived a non linear differential equation system for a mechanical system. However I doubt the correctness of it.
So I compared the model's dynamics with a VREP simulation. I did this by
by Euler ...
0
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1answer
35 views
Is it possible to have open loop with same input term as the output?
For example, i have this differential equation:
$$\dot{y} = 1.8 + 0.58u \sqrt{y}$$
Is it possible to model this system in open loop?? My understanding is that since the term $y$ is in the output ...
1
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1answer
106 views
FEA: What is the difference between a spider of RBE2s and multiple SPCs
I am not sure what the difference is between using a spider of RBE2s. and multiple SPCs across a face. I've heard that the spider is the more accurate method as multiple SPCs make the model overly ...
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0answers
49 views
Distance travelled at articulation point of turning vehicle
Problem outline:
I'm trying to figure out the distance travelled at the articulation point of a turning vehicle with 4 driven wheels (each wheel houses a motor and can all rotate at different RPMs). ...
0
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0answers
29 views
Why would a SMD (spring mass damper) model of steel break down?
Under what conditions would steel be able to be modelled as a 3D SMD model, and under what conditions would the model break down?
1
vote
1answer
107 views
FEA: Newton-Raphson algorithm for Dirichlet BC non-linear static analysis
I have a standard non-linear static problem to solve with FEA. I am applying displacement boundary conditions only, no external force. The equation to solve look like these:
$K(u)u=R(u)$ Eq(1)
The ...
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0answers
17 views
Modeling of a Wireless Channel with known BER
I have to model through software a wireless (my choice: 3g,4g, 802.11...) channel with given Bit Error Rate. I'm searching some distributions, I'm reading tons of papers but I can't find how to ...
1
vote
1answer
24 views
Drucker-Prager Model Parameters, a Proper Choice
My task is to write a code from scratch for 3D elastoplasticity, namely a DP model (see for example DeSouza Neto, et al., 2008, Chapter 8) having yield surface
$$ f(\mathbf{\sigma},c) = \sqrt{J_2(\...
-1
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2answers
43 views
What is the engineering way to describe a factory / manufacturing plant system in a formel and mathematical way
I am interested in mathematically describing as well as formalising a manufacturing plant so that other people in the engineering field understand how the system works. I am not from the engineering ...
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0answers
28 views
Developing a model of rate of cooling of steel tube in air
I am trying to develop an equation to determine the cooling rate of a steel tube in air. I'm using Fourier's Law, Stefan-Boltzman Law, Newton's Law as well as the specific heat capacity equation. The ...
0
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2answers
101 views
Is there any device that can capture a picture into 3D model?
I am currently wondering is there any way or device that can transform a picture into 3D model automatically?
or a machine learning thing to learn from picture (2D) into 3D model?
3
votes
1answer
456 views
Torsional rigidity D vs torsional rigidity factor k vs torsion constant J
I have a physics background so apologize my ignorance.
I'm confused by the constants $D$, $\kappa$, and $J$ when it comes to torsion of beams. From what I understand $\kappa$ and $J$ are the same ...
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0answers
79 views
Am I estimating thrust of a ducted fan correctly?
I'm asking if I'm doing this correctly.
I've estimated the thrust of a ducted-fan model aircraft neglecting pressure changes across the duct as follows:
$$F = Q * \rho * (V_e - V_0)$$
$$= Q * rho * (...
1
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0answers
36 views
“Freeze”/Mold paper in a certain bent position [closed]
I have a piece of paper (lets says its a A4) and I bent it in a certain way (like a skateboard ramp, I'm holding the ends and the middle kind of falls forming this "ramp" model), but now I need a way ...
1
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0answers
98 views
Method to simulate a dipole antenna in salt water?
I am looking to simulate the radiation pattern of a 2.7Ghz half-wavelength dipole antenna immersed in salt water.
I've been using Altair FEKO software to try and accomplish this. I've tried two ...
2
votes
1answer
83 views
How are NPT hole features defined?
I'll be the first to admit that I have always been somewhat confused by best-practice dimensioning standards surrounding pipe threads. While there is a decent amount of literature available online, (...
2
votes
2answers
1k views
Viscoelasticity and Hyperelastic model, history and difference
Actually, I see some papers use viscoelasticity or hyperelastic model for the same materials. It seems to me that those models were invented in different eras, and the hyperelastic is a newer model ...
0
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1answer
86 views
How to get the surface area of trajectory [MSC Adams]?
I'm not sure if the upper question is clear enough to understand but here's what I've got:
I've made a model of excavator in Adams View and got trajectory of it's motion (boom, stick, bucket) using ...
0
votes
1answer
82 views
Parametric equations for fan blades
I'm looking for an explicit numerical example of a parametric surface (u, v) |-> (x(u, v), y(u, v), z(u, v)) that models a fan blade like that in the attached picture.
Googling results in NURBS/PDE ...
