PDE Toolkit - what is d when m is non-zero?

2 visualizzazioni (ultimi 30 giorni)
Sattik Basu
Sattik Basu il 21 Gen 2022
Commentato: Sattik Basu il 25 Gen 2022
To solve the following equation
we need to input values of m,d,c,a and f.
I have been able to input m,c,a,f, however, for d, there is a special rule. The following is from Matlab's own support pages.
It says "Generally, d is either proportional to results results.M, or is a linear combination of results.M and results.K". M and K are matrices obtained after the assembleFEMatrices (i.e., after discretization).
Now, to say the least, this is confusing, as I do have the values of the d matrix (2x2 symmetric matrix in my case). Any insights would be appreciated.
  2 Commenti
Torsten il 21 Gen 2022
If you have a valid MATLAB licence, I'd contact MATLAB support service.
Sattik Basu
Sattik Basu il 21 Gen 2022
Thank you Torsten, I think that is indeed the final option.

Accedi per commentare.

Risposte (1)

Ravi Kumar
Ravi Kumar il 21 Gen 2022
When m is non-zero in a structural problem, d-matrix (coefficient) could represent a damping matrix. That is the most common use case. Hence, the documentation describes how to compute d, proportional damping matrix, as a combination of global mass and stiffness matrix.
  10 Commenti
Torsten il 25 Gen 2022
Thank you for your feedback.
To see whether the reduction to a first-order system works, I'd test it for the acoustic wave equation
d^2u/dt^2 = omega^2 * d^2u/dx^2
and compare with the solution of the formulation as a PDE second order in time.
Sattik Basu
Sattik Basu il 25 Gen 2022
Yes, I am working on validating the answers as we speak. It's always a "state-space" like approach that matlab is comfortable with.

Accedi per commentare.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by