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Questions tagged [modeling]

Use this tag for questions about numerical or analytical modeling and simulation of engineered systems.

3
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1answer
101 views

Is it possible to apply different boundary conditions on the same model for different load cases?

Instead of creating multiple bridge models with different boundary conditions for differential settlement, and combining the forces output manually in Excel, is it possible to specify different ...
1
vote
1answer
34 views

Predicting frequencies, decays, levels, and phases of modes of a circular membrane (drum head)?

I have been working on some acoustic synthesis software for modelling several acoustic instruments. I am using the principle of modal synthesis, where every mode of vibration is individually ...
0
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1answer
32 views

Modeling the stiffness of a membrane

I'm trying to model, in MATLAB, a membrane in 2D which has an initial triangle-like shape. This membrane has pressure acting on it from the inside. There are also some pulling forces in random ...
0
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1answer
54 views

What is the advantage of successive linearization?

In this link, two methods have been referred for linearization. 1- offline linearization 2- online linearization However, I do not understand what is the role of "successive linearization" in the ...
0
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1answer
25 views

Can anyone briefly explain each of the values output by HEC-RAS please

I am looking at a Flood Risk Assessment that uses HEC-RAS to model the predicted levels of flooding on a piece of land. As shown in the attached image, the report lists a number of variables with ...
4
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0answers
68 views

Questions regarding Cornering Stiffness for RC Car

I am a bachelor's level student tasked with modeling the vehicle dynamics of an RC Car that will be made to drive autonomously. I lack prior experience or particularly specific education with vehicle ...
3
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0answers
57 views

How to obtain relative movement and rotation of bridge bearings?

In structural analysis of a bridge using whatever software, such as MIDAS or SAP 2000, it is easy to obtain the deformation of individual nodes. However, for bearings, what we want is the relative ...
2
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0answers
36 views

How to join two beams rigidly?

Hi I am making a beam model using Abaqus. There are two beams created. I wanted to join two beams rigidly in the connection to transfer moments between beams. However, I do not know what connector or ...
2
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0answers
26 views

Holonomic constraint forces using Lagrange multipliers

Consider a multibody robotic system with Lagrangian $$ L =\frac{1}{2} \dot{q}^{T}M\dot{q} - V $$ and equations of motion of the form $$M(q)\ddot{q}+C(q,\dot{q})\dot{q}+A^{T}(q)\lambda+N(q)=0 $$ where ...
2
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0answers
28 views

What specific characteristic of proportional solenoid valves makes the flow to current behavior quadratic?

If experimental data is obtained from a proportional solenoid valve, specifically flow vs current (assuming inlet pressure is constant), the fit is nearly quadratic in nature. Andersen's Analysis and ...
2
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0answers
44 views

How can I model a plane's trajectory in a simple way?

I would like to model a plane trajectory, here are my assumptions and conclusions so far: Assumptions: we denote the plane's speed with $v(t)$, its trajectory $x(t)$, the total trajectory time will ...
2
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0answers
140 views

Modeling heat and mass transfer modes inside rapidly rotating cylinder

My question is about simultaneous heat and mass transfer in rotating cylinder system. System can be detailed as: A rotating cylinder contains wet porous substance in a lump shape. Air stream enters ...
2
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0answers
892 views

What data do I need to plot a BSFC map

I have an 4 stroke spark ignition engine simulator which takes user inputs and outputs performance data. I need rpm, torque and brake specific fuel consumption (bsfc) to plot the bsfc map. I am able ...
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0answers
11 views

How to find the maximum misalignment from vibration?

Consider the system in the (drawn in Paint) image. Assume that there is an input acceleration at the ground defined by a PSD. This acceleration can be in any axis. Points A and B are initially aligned ...
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0answers
19 views

Linear Guidance law into X-Y axis

Im currently writing a model for a guidance law named Maintaining Guidance law. The law looks as following: $$ a_{M} = [K_1,K_2]*[\dot{\lambda_T} ,\dot{\lambda_D}]'$$ Since im using a linear model I ...
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0answers
113 views

How to model ball joint in Patran/Nastran?

I would like to model below mechanical system in Patran. But, I don't know how to configure boundary condition of ball joint. The ball joint is spherically rotated. When the described system is in ...
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0answers
88 views

What are the various lumped element dynamic system models called?

What are the various lumped element dynamic system models called? By lumped element dynamic system models, I mean the various nodal models comprised of things that look like capacitors, inductors, ...
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0answers
45 views

Inventor: How to replace static part with articulation?

I have downloaded the following part file of a servo motor as IGES from the vendor: I have then built an assembly that uses several of these motors, as well as a number of idlers/hubs, brackets, ...
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0answers
91 views

How is rolling resistance accounted for in the Pacejka Curves?

I am simulating the acceleration of a car (FSAE) in a straight line. I have data of the Pacejka Curves ($F_x$ vs. $SR$) of the tire we will be using. The thing is that the curve doesn´t pass through ...
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0answers
25 views

Autodesk Inventor Constraints for Clockwise / Counterclockwise / Dead Points

In the YouTube video Spherical 4-Bar Infinity Mechanism by Thang010146, Dead Points are not compensated for by mechanical means. How can Autodesk Inventor Constraints be applied to such a mechanism to ...
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0answers
93 views

Efficiency model for centrifugal pumps, using relations from Europump's Ecopump project

Context: I'm trying to create a mathematical model for centrifugal pumps. This model should describes how the operational variables of centrifugal pumps $(Q, \Delta P, ...)$ related to it's design ...
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0answers
39 views

Verify parameters variation in local sensitivity coefficients for microkinetic model

I’m performing a sensitivity analysis for a model of a set of elementary chemical reactions. I’m considering the variation in species concentration ($c_{k}$) with respect to the forward reaction rate ...
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0answers
28 views

Iteratively determining conical shock angle from freestream conditions and Taylor-Maccoll Equations

I am currently trying to do a 1D flow analysis of supersonic flow past a semi-infinite cone. My current logic structure is as follows. 1) From given cone angle, $c$, mach number, $M$, and specific ...
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0answers
15 views

Should I use a regular curve fitting tool or system identification to calibrate/model a gyroscope to a reference?

I want to create a model that describes how well a gyroscope can approximate the angular velocity that I apply to it. Since it's never really possible to obtain the exact angular velocity, it is based ...
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0answers
28 views

Bad triangular-shell elements in Abaqus?

Abaqus 6.14 I have a 2D shell mesh reconstructed from a *.ply file. When I verify the mesh I get 55% bad elements (CPS3). So I get a list of all the bad elements & reconstruct the mesh again ...
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0answers
14 views

How to export my model as Solid model IGES Type 186 on Rhino?

I'm not able to find that option while exporting. I need to export this to ANSYS where the other available IGES formats come as only surface models.
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0answers
22 views

False turbulence in laminar flow with k-omega SST

I have a pipe with a sudden expansion from 0.25 mm to 1 mm. Fully developed flow is at the inlet and a reynolds number of 500. I use k-omega SST turbulence model because laminar simulation hasn't ...
0
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0answers
36 views

How to run response spectrum for members with compression only spring in MIDAS

When running a structural model supported on footings with compression only springs, I encountered tension reaction forces in the springs. This occurs when running seismic load case using response ...
0
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0answers
22 views

autocorrelation function of mechanical displacement

I was wondering if there any work in the literature that has been done on the form of the autocorrelation function of mechanical displacement of an object.
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0answers
39 views

1D heat equation for conduction with convective bounary conditions

I have a question related to the 1D heat equation. The equation I have is more complicated with additional terms. Capital T is temperature and is a function of x and t so written as T(x, t) where ...
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0answers
45 views

Help needed with designing a wind turbine (VAWT)

So I have a design for a wind turbine to use in my garden. It is a fairly average darrieus wind turbine design. The wind speed in my garden maxes at about 30mph and constantly changes direction. My ...
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0answers
17 views

How are these bondgraph (de)composition rules for transformers and gyrators derived?

why does a C element through a transformer with transformation ratio n become $C/n^2$ and why does an I element through a gyrator with transformation ratio r become $I/r^2$? Source: Modeling and ...
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0answers
87 views

How can I apply remote force in Pro/E

I am a beginner in ProE and simulation. I would like to apply force in ProE simulation like below picture. Could anyone explain how to put the payload on a remote point?
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0answers
77 views

Looking for an empirical model to simulate a braking resistor

I'm looking for a model of braking resistance to simulate and explore information from a load (power) profile of a fork lift 7[t]. This power load should be handled by a hybrid system (battery +23*...