Re: [deal.II] Mesh-induced elastic anisotropy and distorting the quad. points as a way to palliate it

2020-07-30 Thread David F
be impossible. > > What I'm just noticing: Hexagonal crystals are elastically isotropic > perpendicular to the hexagonal axis. So, my bet on 6 might be good. And it > might explain your observation that the triangular elements are relatively > isotropic (though maybe not perfectly).

Re: [deal.II] Mesh-induced elastic anisotropy and distorting the quad. points as a way to palliate it

2020-07-10 Thread David F
: > > On 7/2/20 10:06 PM, David F wrote: > > > > *_Q2_:* why the system behaves as anisotropic if its local inhomogeneous > > elastic properties are isotropic? If you have any comment or suggestion > about > > the problem of mesh-induced elastic anistropy in FEM, I

[deal.II] Mesh-induced elastic anisotropy and distorting the quad. points as a way to palliate it

2020-07-02 Thread David F
Hello everyone, I'm trying to solve a 2D solid mechanics homogenization problem, in which I have element-wise constant elastic properties, which are inhomogeneous and isotropic from element to element (i.e., I am assembling the system using the same 4-rank stiffness tensor for all the

Re: [deal.II] Using different random seed when distorting a triangulation

2020-05-28 Thread David F
Yes, it seems indeed easy. I'll try to learn how to send it through the official channel in github. On Tuesday, 26 May 2020 05:40:57 UTC+2, Wolfgang Bangerth wrote: > > On 5/25/20 9:20 PM, David F wrote: > > > > I would like to apply many random distortions to a triangu

[deal.II] Using different random seed when distorting a triangulation

2020-05-25 Thread David F
Hello everyone. I would like to apply many random distortions to a triangulation. However, the function GridTools::distort_random seems to produce always the same distortion. Is there a way to use different seeds in order to generate always different distortions? It seems that it's not

[deal.II] Re: Periodicity with simultaneous displacement controlled BCs

2020-04-29 Thread David F
Thank you all, I found the way to do it. For future users trying to solve the same problem, I also found extremely helpful this paper: *Effective properties of composite materials with periodic microstructure: a computational approach, J.C. Michel, H. Moulinec, P. Suquet, Comput. Methods Appl.

[deal.II] Periodicity with simultaneous displacement controlled BCs

2020-04-22 Thread David F
Hello everyone, I'm trying to compute the effective elastic properties of a heterogeneous, linear and a bi-periodic system (i.e., left-right and top-bottom periodic displacement fields). To this system, I would like to apply a global shearing by prescribing the displacement field of the

Re: [deal.II] Is parallel direct solver extremely slow?

2019-03-26 Thread David F
Dear Pai, I'm very interested in solving a problem with characteristics very similar to yours. Consequently, I run your modified code of step-17.cc for 30*30*30 cells and for me it takes 6.43s with cg with -np 2 instead of 0.39s. Do you have any idea where this huge speed up migth come from?

Re: [deal.II] Obtaining the final position of the vertices

2019-03-20 Thread David F
Thank you very much. With those functions in DofTools I should be able to do what I need. Best, David. On Tuesday, 19 March 2019 17:41:32 UTC+1, Wolfgang Bangerth wrote: > > On 3/19/19 9:57 AM, David F wrote: > > > > I am not sure how to answer your question. I'm using a ver

Re: [deal.II] Obtaining the final position of the vertices

2019-03-19 Thread David F
in the form of std::vector> and the final position (i.e., the initial position + its displacement) in the same form. Best, David. On Tuesday, 19 March 2019 16:17:58 UTC+1, Wolfgang Bangerth wrote: > > On 3/19/19 9:12 AM, David F wrote: > > > > I want to obta

[deal.II] Obtaining the final position of the vertices

2019-03-19 Thread David F
Hi all, I want to obtain the final position of the vertices (specifically, the vertices at the faces), i.e., the deformed configuration. I think that a way of doing this is by creating a set of points and using fe_values to extrapolate the solution to those points. However, I don't like the

[deal.II] Calculating gradients at arbitrary points

2017-04-12 Thread David F
Hello, I'm trying to calculate the symmetric gradients of a solution vector at an arbitrary set of points. However, so far I have only found the way to do it at the quadrature points by means of *fe_values[fe_extractor].get_function_symmetric_gradient*. I would like to know what is the proper

Re: [deal.II] Parasitic stress in corners with periodic boundary conditions

2016-09-16 Thread David F
suffered some post processing before I got it, which smoothed the result and somehow hide this. On Monday, 2 June 2014 00:59:11 UTC+2, Wolfgang Bangerth wrote: > > On 05/28/2014 10:29 AM, David F wrote: > > Hello, my problem is the following: > > > > I prescribe an

Re: [deal.II] matrix factorization reuse?

2016-08-30 Thread David F
Hi, I'm interested in this as well. Could you post or link to your solution? Thanks. On Friday, 19 February 2016 17:21:22 UTC+1, Michael Harmon wrote: > > If you want to use Trilinos, I refactored their direct solver so that it > can be used the way you want, I will submit the patch, but if

[deal.II] Efficient implementation of varying Dirichlet BCs when everything else in the system is constant

2016-08-19 Thread David F
Hello everyone, I looked in the forum, in the documentation and in the tutorials but I couldn't find a way to solve this problem in the way I need. I would appreciate a lot any help you could provide me. I would like to have Dirichlet BCs applied to faces with some boundary id. This id is

[deal.II] Efficient implementation of varying Dirichlet BCs when everything else in the system is constant

2016-08-19 Thread David F
Hello everyone, I looked in the forum, in the documentation and in the tutorials but I couldn't find a way to solve this problem in the way I need. I would appreciate a lot any help you could provide me. I would like to have Dirichlet BCs applied to faces with some boundary id. This id is