Reputation
1,949
Top tag
Next privilege 2,000 Rep.
Edit questions and answers
Badges
16 42
Impact
~61k people reached

Sep
24
comment FEM Solution desired for “Plate with orifice” deflection: Application of Boundary Conditions and use of Regions
Thank you! I never tried DSolve for this problem.
Sep
23
comment Time evolution/dynamics of circular plate with hole (Biharmonic equation and stiffness)
@bbgodfrey I am not sure. However, I am curious to know what the deflection (w) is at "long times". If for a negative time derivative, it is around the same value as the question this refers to, I would say, YES, the time derivative should be reversed. I hope that make sense? Thank you for pointing out that possible source of error.
Sep
23
comment Time evolution/dynamics of circular plate with hole (Biharmonic equation and stiffness)
@bbgodfrey They do exist for rectangular plates with rectangular and circular holes 1. Empirical solutions for circular plate with hole for deflections are readily available though. I did find a book entry by Timoshenko on elastic stability of circular plates with and without a hole 2. I do not have access to this paper.
Sep
22
comment Time evolution/dynamics of circular plate with hole (Biharmonic equation and stiffness)
@bbgodfrey 0.33 is a good standard value for nu.
Sep
22
comment Time evolution/dynamics of circular plate with hole (Biharmonic equation and stiffness)
@bbgodfrey yes it is supposed to be nu which is defined. It is poissons ratio . (can't type efficiently on phone right now...)
Sep
22
asked Using BSpline as initial condition in NDSolve
Sep
21
comment Nonlinear differential equation: numerical solution
I have generally found that for equations with singularities due to a 1/x type term, Method->"LSODA" has usually worked wonders. LSODA has generally been more time efficient than ExplicitRungeKutta and efficient in resolving stiffness.
Sep
20
awarded  Popular Question
Sep
19
comment ODE w/seasonal forcing term
Can you share what book you are using?
Sep
19
comment Time evolution/dynamics of circular plate with hole (Biharmonic equation and stiffness)
@xzczd It does return an interpolating function. However, this interpolating function gives a plot that shows a deflection and deflection "shape" that doesn't approach what was calculated here. I have made an edit to the question to reflect your comment.
Sep
19
revised Time evolution/dynamics of circular plate with hole (Biharmonic equation and stiffness)
added 1505 characters in body
Sep
19
comment Solving a nonlinear PDE with Mathematica10 FEM Solver
Is FEM a must? I have had a lot of success with non linear PDEs with NDSolve. Yes, you will have to deal with stiffness but the Method->LSODA is quite the "golden hammer" for stiff non linear problems.
Sep
19
comment Nonlinear FEM Solver for Navier-Stokes equations in 2D
What fluid dynamics problem are you trying to solve? Lid driven flow? This information will be useful.
Sep
18
revised Time evolution/dynamics of circular plate with hole (Biharmonic equation and stiffness)
edited title
Sep
18
awarded  Promoter
Sep
14
revised Time evolution/dynamics of circular plate with hole (Biharmonic equation and stiffness)
added 30 characters in body
Sep
14
asked Time evolution/dynamics of circular plate with hole (Biharmonic equation and stiffness)
Sep
10
accepted Mathematica not responding to clean start-up
Sep
10
comment Mathematica not responding to clean start-up
@ilian I know that this has been answered elsewhere but can you post our chat transcript (which was a definitive solution) as an answer? I assume that is allowed (since this is the internet?)
Sep
10
comment Mathematica not responding to clean start-up
@Gansukh if you read the chat transcript between me and ilian (from a few comments above), you will find a solution described in there.