# Questions tagged [modeling]

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

35 questions
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### 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?
101 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 ...
40 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 ...
124 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 ...
45 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 ...
84 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 ...
69 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 ...
46 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 ...
29 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 ...
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### 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 ...
47 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 ...
149 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 ...
966 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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### 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 ...
100 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, ...
52 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, ...
105 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 ...
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 ...
95 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 ...
40 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 ...
13 views

### Source for learning Functional derivative , Gateaux derivative

I have started doing research in optimal control theory. My area of research is PDE constrained optimization. I am facing significant difficulty in deriving the Gateaux Derivative of functionals ...
19 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 ...
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 ...
43 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 ...
17 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.
38 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 ...
55 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 ...
30 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.
19 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 ...