subject:"\[deal.II\] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material"

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

2020-12-29 Thread Jean-Paul Pelteret


HI Animesh,

You forgot to show the most critical part of the error report in your 
post: The actual source line that's causing the problem! Thankfully it 
was included in the error log that you uploaded.


In file included from 
/home/animesh/Documents/dealii/dealii-9.2.0/examples/Quasi_static_Finite_strain_Compressible_Elasticity/cook_membrane.cc:73:0:
/usr/local/include/deal.II/physics/elasticity/kinematics.h: In 
instantiation of ‘dealii::Tensor<2, dim, Number> 
dealii::Physics::Elasticity::Kinematics::F_iso(const dealii::Tensor<2, 
dim, Number>&) [with int dim = 2; Number = 
Sacado::Fad::Exp::GeneralFaddouble> >]’:
/home/animesh/Documents/dealii/dealii-9.2.0/examples/Quasi_static_Finite_strain_Compressible_Elasticity/cook_membrane.cc:1861:90: 
required from ‘void Cook_Membrane::AssemblerSacado::Fad::Exp::GeneralFaddouble> > >::assemble_system_tangent_residual_one_cell(const typename 
dealii::DoFHandler::active_cell_iterator&, typename 
Cook_Membrane::Assembler_BaseSacado::Fad::Exp::GeneralFaddouble> > >::ScratchData_ASM&, typename 
Cook_Membrane::Assembler_BaseSacado::Fad::Exp::GeneralFaddouble> > >::PerTaskData_ASM&) [with int dim = 2; typename 
dealii::DoFHandler::active_cell_iterator = 
dealii::TriaActiveIterator2>, false> >; typename Cook_Membrane::Assembler_BaseSacado::Fad::Exp::GeneralFaddouble> > >::ScratchData_ASM = Cook_Membrane::Assembler_Base<2, 
Sacado::Fad::Exp::GeneralFaddouble> > >::ScratchData_ASM; typename 
Cook_Membrane::Assembler_BaseSacado::Fad::Exp::GeneralFaddouble> > >::PerTaskData_ASM = Cook_Membrane::Assembler_Base<2, 
Sacado::Fad::Exp::GeneralFaddouble> > >::PerTaskData_ASM]’
/home/animesh/Documents/dealii/dealii-9.2.0/examples/Quasi_static_Finite_strain_Compressible_Elasticity/cook_membrane.cc:2325:1: 
required from here
/usr/local/include/deal.II/physics/elasticity/kinematics.h:294:47: 
error: no match for ‘operator*’ (operand types are 
‘Sacado::Fad::Exp::PowerOpdouble> >, double, false, true, Sacado::Fad::Exp::ExprSpecDefault, 
Sacado::Fad::Exp::PowerImpl::Scalar>’ and ‘const dealii::Tensor<2, 2, 
Sacado::Fad::Exp::GeneralFaddouble> > >’)

   return std::pow(determinant(F), -1.0 / dim) * F;
  ~^~~

What's going on here is that Sacado's implementation of the pow() 
function returns a specialised number type that deal.II doesn't 
recognise (this Sacado number type uses expression templates, which 
means that every operation returns a specialised type, and not the 
original AD number type). I guess that we could try to detect this and 
implement support in the operator* for Tensors and SymmetricTensors (and 
probably in other places in the library), but this would only be 
possible if Sacado has some type traits to help us filter out which of 
these special numbers are indeed Sacado types. I'm pretty sure that they 
do have such traits, but its been some time since we implemented this so 
I cannot remember for certain.


For now,the simple solution would be to cast the LHS value to a Sacado 
type. like this:


return SacadoNumberType(std::pow(determinant(F), -1.0 / dim)) * F;

where SacadoNumberType is some type definition for the Sacado type that 
you're using. We certainly have support for premultiplication of a 
Tensor by another SacadoNumberType.


I hope that this fixes the issue for you.

Best,
Jean-Paul

On 29.12.20 12:55, Animesh Rastogi IIT Gandhinagar wrote:

Hi Jean-Paul,

I have reconfigured and reinstalled dealii with Trilinos so that I can 
use the eigenvalue functionality from Trilinos.


When I am running the Quasi_Static_compressibility (cook_membrane) 
code from the code gallery, I am getting the following error. I did 
not face this issue when my dealii was not compiled with Trilinos.


/home/animesh/Documents/dealii/dealii-9.2.0/examples/Quasi_static_Finite_strain_Compressible_Elasticity/cook_membrane.cc:2325:1: 
required from here
/home/animesh/share/trilinos/include/Sacado_Fad_Exp_Ops.hpp:775:1: 
*error*: no type named ‘type’ in ‘struct 
Sacado::mpl::enable_if_cSacado::Fad::Exp::MultiplicationOpdouble> >, double, false, true, Sacado::Fad::Exp::ExprSpecDefault, 
Sacado::Fad::Exp::PowerImpl::Scalar>, dealii::Tensor<2, 2, 
Sacado::Fad::Exp::GeneralFaddouble> > >, false, false, Sacado::Fad::Exp::ExprSpecDefault> >’
CMakeFiles/cook_membrane.dir/build.make:62: recipe for target 
'CMakeFiles/cook_membrane.dir/cook_membrane.cc.o' failed

make[3]: *** [CMakeFiles/cook_membrane.dir/cook_membrane.cc.o] Error 1
CMakeFiles/Makefile2:195: recipe for target 
'CMakeFiles/cook_membrane.dir/all' failed

make[2]: *** [CMakeFiles/cook_membrane.dir/all] Error 2
CMakeFiles/Makefile2:138: recipe for target 'CMakeFiles/run.dir/rule' 
failed

make[1]: *** [CMakeFiles/run.dir/rule] Error 2
Makefile:144: recipe for target 'run' failed
make: *** [run] Error 2


Could you please let me know how to get rid of this issue?

I am attaching the full command line output when I ran the 
cook_membrane's program and cmake command used to build

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

2020-11-24 Thread Jean-Paul Pelteret


Dear Animesh,

Well, with such a small incremental displacement its probable that 
you're either working in the linear range of the constitutive model or 
that the update between equilibrium states is at least linear. So after 
a single Newton iteration you have probably converged system, and given 
that the relative error norms do not decrease any further it is also 
probable that its converged down to machine precision. You can check 
this by printing out the absolute error norms in addition to the 
relative error norms (see 
https://github.com/dealii/code-gallery/blob/master/Quasi_static_Finite_strain_Compressible_Elasticity/cook_membrane.cc#L1354-L1355 
). 
If you're satisfied that that this the "problem" (i.e. that the system 
is converged but its not being detected by the nonlinear solver) then 
you can simply amend the convergence criteria for the NL solver (see 
https://github.com/dealii/code-gallery/blob/master/Quasi_static_Finite_strain_Compressible_Elasticity/cook_membrane.cc#L1272-L1273 
) 
to include checks on the absolute error.


I hope that this helps.
Jean-Paul

On 23.11.20 11:03, Animesh Rastogi IIT Gandhinagar wrote:

Hi Jean-Paul,

Thank you for your detailed response. I checked everything twice and 
found my code consistent with what you suggested. I think I understood 
the issue of Newton method convergence. The issue is occurring when I 
am giving a very small compressive displacement as a boundary 
condition (near -1e-06).


Is there anyway I can get the solution converged even with a very 
small compressive displacement?


Thanks!

Animesh

I am getting something like following -

Assembly method: Residual and linearisation are computed manually.
Grid:
     Reference volume: 1200
Triangulation:
     Number of active cells: 4800
     Number ofset degrees of freedom: 9922
    Setting up quadrature point data...

Timestep 1 @ 1s
___
    SOLVER STEP |  LIN_IT   LIN_RES    RES_NORM RES_U 
NU_NORM  NU_U

___
  0  CST  ASM  SLV  |   1  0.000e+00  1.000e+00 1.000e+00    
1.000e+00  1.000e+00
  1  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
  2  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
  3  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
  4  CST  ASM  SLV  |   1  0.000e+00  7.223e-09 7.223e-09    
2.843e-08  2.843e-08
  5  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
  6  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
  7  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
  8  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
  9  CST  ASM  SLV  |   1  0.000e+00  7.223e-09 7.223e-09    
2.843e-08  2.843e-08
 10  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 11  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 12  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 13  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 14  CST  ASM  SLV  |   1  0.000e+00  7.223e-09 7.223e-09    
2.843e-08  2.843e-08
 15  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 16  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 17  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 18  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 19  CST  ASM  SLV  |   1  0.000e+00  7.223e-09 7.223e-09    
2.843e-08  2.843e-08
 20  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 21  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 22  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 23  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 24  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09
 25  CST  ASM  SLV  |   1  0.000e+00  7.223e-09 7.223e-09    
2.843e-08  2.843e-08
 26  CST  ASM  SLV  |   1  0.000e+00  1.696e-09 1.696e-09    
6.675e-09  6.675e-09

..


On Thursday, November 12, 2020 at 1:34:30 PM UTC+5:30 Jean-Paul 
Pelteret wrote:


Hi Animesh,


> In the documentation in code gallery

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

2020-11-23 Thread Animesh Rastogi IIT Gandhinagar

Hi Jean-Paul,

Thank you for your detailed response. I checked everything twice and found 
my code consistent with what you suggested. I think I understood the issue 
of Newton method convergence. The issue is occurring when I am giving a 
very small compressive displacement as a boundary condition (near -1e-06). 

Is there anyway I can get the solution converged even with a very small 
compressive displacement?

Thanks!

Animesh

I am getting something like following - 

Assembly method: Residual and linearisation are computed manually.
Grid:
 Reference volume: 1200
Triangulation:
 Number of active cells: 4800
 Number ofset degrees of freedom: 9922
Setting up quadrature point data...

Timestep 1 @ 1s
___
SOLVER STEP |  LIN_IT   LIN_RESRES_NORM RES_U 
NU_NORM  NU_U 
___
  0  CST  ASM  SLV  |   1  0.000e+00  1.000e+00  1.000e+00
1.000e+00  1.000e+00  
  1  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
  2  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
  3  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
  4  CST  ASM  SLV  |   1  0.000e+00  7.223e-09  7.223e-09
2.843e-08  2.843e-08  
  5  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
  6  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
  7  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
  8  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
  9  CST  ASM  SLV  |   1  0.000e+00  7.223e-09  7.223e-09
2.843e-08  2.843e-08  
 10  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 11  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 12  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 13  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 14  CST  ASM  SLV  |   1  0.000e+00  7.223e-09  7.223e-09
2.843e-08  2.843e-08  
 15  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 16  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 17  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 18  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 19  CST  ASM  SLV  |   1  0.000e+00  7.223e-09  7.223e-09
2.843e-08  2.843e-08  
 20  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 21  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 22  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 23  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 24  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
 25  CST  ASM  SLV  |   1  0.000e+00  7.223e-09  7.223e-09
2.843e-08  2.843e-08  
 26  CST  ASM  SLV  |   1  0.000e+00  1.696e-09  1.696e-09
6.675e-09  6.675e-09  
..


On Thursday, November 12, 2020 at 1:34:30 PM UTC+5:30 Jean-Paul Pelteret 
wrote:

> Hi Animesh,
>
>
> > In the documentation in code gallery 
> ,
>  
> it is written that -
>
> This code is based off of step-44, and its documentation is largely 
> identical to what's written there. It looks like that comment was missed 
> when adjustments were being made to the documentation, so you should ignore 
> it. You can see that the stress and tangent are computed directly using the 
> kinematic variables passed as arguments to the class methods:
>
> const SymmetricTensor<2,dim,NumberType> 
>  
> tau = lqph[q_point]->get_tau(det_F,b_bar);
> const SymmetricTensor<4,dim,NumberType> 
>  
> Jc = lqph[q_point]->get_Jc(det_F,b_bar);
>
> > I would also need to update the quadrature point data to the previous 
> step. Could you please let me know, how am I supposed to do that? 
>
> You can see from the code snippet , as well as from the way that the 
> assembly is structured
>
> template 
> void Solid::assemble_system(const BlockVector 
>  
> _delta)
> {
> ...
> const BlockVector 
>  
> solution_total(get_total_solution(solution_delta));
> ...
> }
>
> template

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

2020-11-12 Thread Jean-Paul Pelteret

Hi Animesh,

> In the documentation in code gallery 
, 
it is written that -

This code is based off of step-44, and its documentation is largely 
identical to what's written there. It looks like that comment was missed 
when adjustments were being made to the documentation, so you should 
ignore it. You can see that the stress and tangent are computed directly 
using the kinematic variables passed as arguments to the class methods:

const SymmetricTensor<2,dim,NumberType> 

tau = lqph[q_point]->get_tau(det_F,b_bar);
const SymmetricTensor<4,dim,NumberType> 

Jc = lqph[q_point]->get_Jc(det_F,b_bar);

> I would also need to update the quadrature point data to the previous 
step. Could you please let me know, how am I supposed to do that?

You can see from the code snippet , as well as from the way that the 
assembly is structured

template 
void Solid::assemble_system(const BlockVector 

_delta)

{
...
const BlockVector 

solution_total(get_total_solution(solution_delta));

...
}

template 
BlockVector 

Solid::get_total_solution(const BlockVector 

_delta)const

{
BlockVector 

solution_total(solution_n);

solution_total += solution_delta;
return solution_total;
}

that the only requirement to ensure a consistent state for the entire 
problem is that the addition of "solution_n" with "solution_delta" 
reflects the configuration of the body that you're wanting. So if that 
you're doing in the main "time loop" is something like

while (time.current() <= time.end())
{
solution_delta = 0.0;
solve_nonlinear_timestep(solution_delta);
solution_n += solution_delta;

auto tmp_soln_delta = solution_delta;

solution_delta = 0.0; // get_total_solution() takes in the 
soltuion_delta, so don't solve the eigenvalue problem with the delta 
accounted for twice

const bool accept_step = solve_eigenvalue_problem();
if (accept_step == false)
{
  solution_n -= tmp_soln_delta;
adjust_boundary_conditions_or_timestep_size_to_apply_a_smaller_displacement_increment();
}

time.increment();
}

then that would seem a reasonable approach to me. As I said before, the 
stresses and strains are kept in sync with the solution_total within the 
assembly loop.

I hope that this helps you to locate the source of your issues.

Best,
Jean-Paul

On 10.11.20 16:06, Animesh Rastogi IIT Gandhinagar wrote:

Hi Jean-Paul,

Another question which might be the reason why I am getting the 
inconsistencies in my newton-raphson convergence. I just realised this..

What I am doing is the following -

I am giving small compressive displacements to the film+substrate. I 
am also calculating the eigenvalues of the tangent_stiffness matrix 
(after the convergence of newton method), to understand the stability 
of the system. The moment I encounter a negative smallest eigenvalue, 
I want to go to a previous time step and would like to solve for a 
small compressive displacement. For instance, if the compression is 
0.1 at this time step and the eigenvalue is negative, I go to the 
previous time step and give a compressive displacement of 0.05.

Here is my concern, I have added a condition that, if I find a 
negative eigenvalue during any time step, I update the /solution_n = 
solution_n - solution_delta/; and then run the time step again (with a 
smaller compressive displacement) after doing /solution_delta = 0.0/. 
Since the next state is also dependent on the updated quadrature point 
data (stresses etc.), I would also need to update the quadrature point 
data to the previous step. Could you please let me know, how am I 
supposed to do that?

In the documentation in code gallery 
, 
it is written that -

"/The first function is used to create a material object and to 
initialize all tensors correctly: The second one updates the stored 
values and stresses based on the current deformation measure 
//Grad//u//n/" (inside the Point History class). However, I only find 
one function which is setup_lqp, and not the update_lqp or something 
similar.

Thanks!

Animesh

On Tuesday, November 10, 2020 at 5:24:13 PM UTC+5:30 Animesh Rastogi 
IIT Gandhinagar wrote:

Hi Jean-Paul,

There seem to be some inconsistencies in the simulations results
that I am getting, therefore I wanted to check if I have applied
the material laws properly

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

2020-11-11 Thread Jean-Paul Pelteret


Hi Animesh,

All of this seems reasonable to me. When you ask each PointHistory class 
instance for its stress etc., it will forward the call to the specific 
material instance that is initialised with one of the two sets of 
material parameters that you're setting in the parameters file.


Best,
Jean-Paul

On 10.11.20 12:54, Animesh Rastogi IIT Gandhinagar wrote:

Hi Jean-Paul,

There seem to be some inconsistencies in the simulations results that 
I am getting, therefore I wanted to check if I have applied the 
material laws properly accounting for the heterogeneities. Below, I 
have addted the edited functions that are responsible for that. Could 
you please let me know if there is something wrong here? I have 
checked the material properties (mu1, mu2 etc), and they are being 
read correctly by the code from the parameters file. I have also 
checked that the material ids (1 and 2) are correctly applied to the 
cells where I need them.


--
void setup_lqp (const Parameters::AllParameters , const 
unsigned int )

    {

    //Material 1 - Thin Film
if (materialid == 1)
    {
std::cout<<"1_id"<  material.reset(new 
Material_Compressible_Neo_Hook_One_Field(parameters.mu1,

 parameters.nu1));
    }
    //Material 2 - Substrate
    if (materialid ==2)
    {
  material.reset(new 
Material_Compressible_Neo_Hook_One_Field(parameters.mu2,

   parameters.nu2));
    }

    }

---

template 
  void Solid::setup_qph()
  {
    std::cout << "    Setting up quadrature point data..." << std::endl;

quadrature_point_history.initialize(triangulation.begin_active(),
    triangulation.end(),
    n_q_points);

    for (typename Triangulation::active_cell_iterator cell =
   triangulation.begin_active(); cell != triangulation.end(); 
++cell)

  {
    const std::vector 
> > lqph =

  quadrature_point_history.get_data(cell);
    Assert(lqph.size() == n_q_points, ExcInternalError());

    for (unsigned int q_point = 0; q_point < n_q_points; ++q_point)
  lqph[q_point]->setup_lqp(parameters, cell->material_id());
  }
  }

--

Thanks!

Animesh
On Tuesday, November 3, 2020 at 12:09:03 PM UTC+5:30 Animesh Rastogi 
IIT Gandhinagar wrote:


Hi Jean,

Sorry for late response. Thank you for your detailed answer. Using
your suggestions I was able to assign the material ids to
different area of my domain of interest.

Thanks again!

Animesh

On Tuesday, October 27, 2020 at 3:05:39 AM UTC+5:30 Jean-Paul
Pelteret wrote:

Dear Animesh,

Let me preface my suggestion by saying that you can introduce
some heterogeneity in more than one way. That is, you're not
bound to using a material ID (which is what I'm going to
suggest), but you could use some geometric arguments to
determine which class or material properties should dictate
the constitutive response at a continuum point. You also need
not use the class-based structure that this code galley
example has. There are other tutorials (e.g. step-8) that use
Functions that return the material coefficients at any point
in space. So you should keep that in mind as you read my
suggestion.

In my opinion, the simplest approach would be the following:

1. The PointHistory::setup_lqp() function


is the point at which the constitutive law at some quadrature
point is set. So you should extend this function in some way
to make a decision about which material it is in, and what the
material law at that point is. The first thing that you might
do is add an argument for the material ID, and then choose
constiutitve parameters based on the material ID. You'll note
that the concrete constitutive law is stored in a pointer.
This makes it easy to extend to support other constitutive
laws, because you can for example abstract the
Material_Compressible_Neo_Hook_One_Field class into some base
class and other classes (maybe a
Material_Compressible_Mooney_Rivlin_One_Field) and then, based
on the material ID, select which constitutive law is applied
at that quadrature point.
2. The PointHistory::setup_lqp() function is called from
Solid::setup_qph()


, and more specifically inside a loop over all cells. Its
possible to retrieve the cell->material_id() or cell->center()
(or, if

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

2020-11-10 Thread Animesh Rastogi IIT Gandhinagar

Hi Jean-Paul,

Another question which might be the reason why I am getting the 
inconsistencies in my newton-raphson convergence. I just realised this..

What I am doing is the following - 

I am giving small compressive displacements to the film+substrate. I am 
also calculating the eigenvalues of the tangent_stiffness matrix (after the 
convergence of newton method), to understand the stability of the system. 
The moment I encounter a negative smallest eigenvalue, I want to go to a 
previous time step and would like to solve for a small compressive 
displacement. For instance, if the compression is 0.1 at this time step and 
the eigenvalue is negative, I go to the previous time step and give a 
compressive displacement of 0.05.

Here is my concern, I have added a condition that, if I find a negative 
eigenvalue during any time step, I update the *solution_n = solution_n - 
solution_delta*; and then run the time step again (with a smaller 
compressive displacement) after doing *solution_delta = 0.0*. Since the 
next state is also dependent on the updated quadrature point data (stresses 
etc.), I would also need to update the quadrature point data to the 
previous step. Could you please let me know, how am I supposed to do that? 

In the documentation in code gallery 
,

it is written that - 

"*The first function is used to create a material object and to initialize 
all tensors correctly: The second one updates the stored values and 
stresses based on the current deformation measure **Grad**u**n*"  (inside 
the Point History class). However, I only find one function which is 
setup_lqp, and not the update_lqp or something similar. 

Thanks!

Animesh

On Tuesday, November 10, 2020 at 5:24:13 PM UTC+5:30 Animesh Rastogi IIT 
Gandhinagar wrote:

> Hi Jean-Paul, 
>
> There seem to be some inconsistencies in the simulations results that I am 
> getting, therefore I wanted to check if I have applied the material laws 
> properly accounting for the heterogeneities. Below, I have addted the 
> edited functions that are responsible for that. Could you please let me 
> know if there is something wrong here? I have checked the material 
> properties (mu1, mu2 etc), and they are being read correctly by the code 
> from the parameters file. I have also checked that the material ids (1 and 
> 2) are correctly applied to the cells where I need them. 
>
> --
> void setup_lqp (const Parameters::AllParameters , const 
> unsigned int )
> {
>
> //Material 1 - Thin Film
> if (materialid == 1)
> {
>  
> std::cout<<"1_id"<   material.reset(new 
> Material_Compressible_Neo_Hook_One_Field(parameters.mu1,
>  parameters.nu1));
> }
> //Material 2 - Substrate
> if (materialid ==2)
> {
>   material.reset(new 
> Material_Compressible_Neo_Hook_One_Field(parameters.mu2,
>parameters.nu2));
> }
>
> }
>
> ---
>
> template 
>   void Solid::setup_qph()
>   {
> std::cout << "Setting up quadrature point data..." << std::endl;
>
> quadrature_point_history.initialize(triangulation.begin_active(),
> triangulation.end(),
> n_q_points);
>
> for (typename Triangulation::active_cell_iterator cell =
>triangulation.begin_active(); cell != triangulation.end(); 
> ++cell)
>   {
> const std::vector > > 
> lqph =
>   quadrature_point_history.get_data(cell);
> Assert(lqph.size() == n_q_points, ExcInternalError());
>
> for (unsigned int q_point = 0; q_point < n_q_points; ++q_point)
>   lqph[q_point]->setup_lqp(parameters, cell->material_id());
>   }
>   }
>
> --
>
> Thanks!
>
> Animesh
> On Tuesday, November 3, 2020 at 12:09:03 PM UTC+5:30 Animesh Rastogi IIT 
> Gandhinagar wrote:
>
>> Hi Jean, 
>>
>> Sorry for late response. Thank you for your detailed answer. Using your 
>> suggestions I was able to assign the material ids to different area of my 
>> domain of interest. 
>>
>> Thanks again!
>>
>> Animesh
>>
>> On Tuesday, October 27, 2020 at 3:05:39 AM UTC+5:30 Jean-Paul Pelteret 
>> wrote:
>>
>>> Dear Animesh,
>>>
>>> Let me preface my suggestion by saying that you can introduce some 
>>> heterogeneity in more than one way. That is, you're not bound to using a 
>>> material ID (which is what I'm going to suggest), but you could use some 
>>> geometric arguments to determine which class or material properties should 
>>> dictate the constitutive response at a continuum point. You also need not 
>>> use the class-based structure that this code galley example has. There are 
>>> other tutorials (e.g. step-8) that use Functions that return the material 
>>> coefficients at any point

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

2020-11-10 Thread Animesh Rastogi IIT Gandhinagar

Hi Jean-Paul, 

There seem to be some inconsistencies in the simulations results that I am 
getting, therefore I wanted to check if I have applied the material laws 
properly accounting for the heterogeneities. Below, I have addted the 
edited functions that are responsible for that. Could you please let me 
know if there is something wrong here? I have checked the material 
properties (mu1, mu2 etc), and they are being read correctly by the code 
from the parameters file. I have also checked that the material ids (1 and 
2) are correctly applied to the cells where I need them. 

--
void setup_lqp (const Parameters::AllParameters , const unsigned 
int )
{

//Material 1 - Thin Film
if (materialid == 1)
{
 
std::cout<<"1_id"<(parameters.mu1,
 parameters.nu1));
}
//Material 2 - Substrate
if (materialid ==2)
{
  material.reset(new 
Material_Compressible_Neo_Hook_One_Field(parameters.mu2,
   parameters.nu2));
}

}

---

template 
  void Solid::setup_qph()
  {
std::cout << "Setting up quadrature point data..." << std::endl;

quadrature_point_history.initialize(triangulation.begin_active(),
triangulation.end(),
n_q_points);

for (typename Triangulation::active_cell_iterator cell =
   triangulation.begin_active(); cell != triangulation.end(); 
++cell)
  {
const std::vector > > 
lqph =
  quadrature_point_history.get_data(cell);
Assert(lqph.size() == n_q_points, ExcInternalError());

for (unsigned int q_point = 0; q_point < n_q_points; ++q_point)
  lqph[q_point]->setup_lqp(parameters, cell->material_id());
  }
  }

--

Thanks!

Animesh
On Tuesday, November 3, 2020 at 12:09:03 PM UTC+5:30 Animesh Rastogi IIT 
Gandhinagar wrote:

> Hi Jean, 
>
> Sorry for late response. Thank you for your detailed answer. Using your 
> suggestions I was able to assign the material ids to different area of my 
> domain of interest. 
>
> Thanks again!
>
> Animesh
>
> On Tuesday, October 27, 2020 at 3:05:39 AM UTC+5:30 Jean-Paul Pelteret 
> wrote:
>
>> Dear Animesh,
>>
>> Let me preface my suggestion by saying that you can introduce some 
>> heterogeneity in more than one way. That is, you're not bound to using a 
>> material ID (which is what I'm going to suggest), but you could use some 
>> geometric arguments to determine which class or material properties should 
>> dictate the constitutive response at a continuum point. You also need not 
>> use the class-based structure that this code galley example has. There are 
>> other tutorials (e.g. step-8) that use Functions that return the material 
>> coefficients at any point in space. So you should keep that in mind as you 
>> read my suggestion.
>>
>> In my opinion, the simplest approach would be the following:
>>
>> 1. The PointHistory::setup_lqp() function 
>> 
>>  
>> is the point at which the constitutive law at some quadrature point is set. 
>> So you should extend this function in some way to make a decision about 
>> which material it is in, and what the material law at that point is. The 
>> first thing that you might do is add an argument for the material ID, and 
>> then choose constiutitve parameters based on the material ID. You'll note 
>> that the concrete constitutive law is stored in a pointer. This makes it 
>> easy to extend to support other constitutive laws, because you can for 
>> example abstract the Material_Compressible_Neo_Hook_One_Field class into 
>> some base class and other classes (maybe a 
>> Material_Compressible_Mooney_Rivlin_One_Field) and then, based on the 
>> material ID, select which constitutive law is applied at that quadrature 
>> point. 
>> 2. The PointHistory::setup_lqp() function is called from 
>> Solid::setup_qph() 
>> 
>>  
>> , and more specifically inside a loop over all cells. Its possible to 
>> retrieve the cell->material_id() or cell->center() (or, if you create a 
>> quadrature rule to help you then you can get the actual position of the 
>> quadrature point if you want such granularity). You can then pass this 
>> information in to PointHistory::setup_lqp() to help decide which 
>> constitutive law / parameters to apply. If using the material ID then you 
>> will, of course, want to set the material ID when building or reading in 
>> your triangulation.
>>
>> That is, at least, how I typically do things when using this code as a 
>> basis for extension. I hope that this helps you introduce heterogeneities 
>> into your

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

2020-11-02 Thread Animesh Rastogi IIT Gandhinagar

Hi Jean, 

Sorry for late response. Thank you for your detailed answer. Using your 
suggestions I was able to assign the material ids to different area of my 
domain of interest. 

Thanks again!

Animesh

On Tuesday, October 27, 2020 at 3:05:39 AM UTC+5:30 Jean-Paul Pelteret 
wrote:

> Dear Animesh,
>
> Let me preface my suggestion by saying that you can introduce some 
> heterogeneity in more than one way. That is, you're not bound to using a 
> material ID (which is what I'm going to suggest), but you could use some 
> geometric arguments to determine which class or material properties should 
> dictate the constitutive response at a continuum point. You also need not 
> use the class-based structure that this code galley example has. There are 
> other tutorials (e.g. step-8) that use Functions that return the material 
> coefficients at any point in space. So you should keep that in mind as you 
> read my suggestion.
>
> In my opinion, the simplest approach would be the following:
>
> 1. The PointHistory::setup_lqp() function 
> 
>  
> is the point at which the constitutive law at some quadrature point is set. 
> So you should extend this function in some way to make a decision about 
> which material it is in, and what the material law at that point is. The 
> first thing that you might do is add an argument for the material ID, and 
> then choose constiutitve parameters based on the material ID. You'll note 
> that the concrete constitutive law is stored in a pointer. This makes it 
> easy to extend to support other constitutive laws, because you can for 
> example abstract the Material_Compressible_Neo_Hook_One_Field class into 
> some base class and other classes (maybe a 
> Material_Compressible_Mooney_Rivlin_One_Field) and then, based on the 
> material ID, select which constitutive law is applied at that quadrature 
> point. 
> 2. The PointHistory::setup_lqp() function is called from 
> Solid::setup_qph() 
> 
>  
> , and more specifically inside a loop over all cells. Its possible to 
> retrieve the cell->material_id() or cell->center() (or, if you create a 
> quadrature rule to help you then you can get the actual position of the 
> quadrature point if you want such granularity). You can then pass this 
> information in to PointHistory::setup_lqp() to help decide which 
> constitutive law / parameters to apply. If using the material ID then you 
> will, of course, want to set the material ID when building or reading in 
> your triangulation.
>
> That is, at least, how I typically do things when using this code as a 
> basis for extension. I hope that this helps you introduce heterogeneities 
> into your problem!
>
> Best,
> Jean-Paul
>
>
> On 26.10.20 08:15, Animesh Rastogi IIT Gandhinagar wrote:
>
> Hello All,
>
> I am trying to solve the wrinkling problem of a thin stiff film attached 
> to a soft substrate in dealii. I am using the code - from the code gallery 
> for this purpose. For the simulations, I would have to consider the film 
> and the substrate with different material properties.
>
> I understand that I would have to do something within the class Qudrature 
> point history. However, I am getting a little confused on how to approach 
> it. It would be great if someone could help me with this. 
>
> This is the code that I am using for this purpose - 
> https://dealii.org/developer/doxygen/deal.II/code_gallery_Quasi_static_Finite_strain_Compressible_Elasticity.html
>
> Thanks!
>
> Animesh
>
> -- 
> The deal.II project is located at http://www.dealii.org/
> For mailing list/forum options, see 
> https://groups.google.com/d/forum/dealii?hl=en
> --- 
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> "deal.II User Group" group.
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> email to dealii+un...@googlegroups.com.
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> https://groups.google.com/d/msgid/dealii/26db8831-e190-4fcd-8247-b7172ab880fen%40googlegroups.com
>  
> 
> .
>
>
>

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Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

2020-10-26 Thread Jean-Paul Pelteret


Dear Animesh,

Let me preface my suggestion by saying that you can introduce some 
heterogeneity in more than one way. That is, you're not bound to using a 
material ID (which is what I'm going to suggest), but you could use some 
geometric arguments to determine which class or material properties 
should dictate the constitutive response at a continuum point. You also 
need not use the class-based structure that this code galley example 
has. There are other tutorials (e.g. step-8) that use Functions that 
return the material coefficients at any point in space. So you should 
keep that in mind as you read my suggestion.


In my opinion, the simplest approach would be the following:

1. The PointHistory::setup_lqp() function 
 
is the point at which the constitutive law at some quadrature point is 
set. So you should extend this function in some way to make a decision 
about which material it is in, and what the material law at that point 
is. The first thing that you might do is add an argument for the 
material ID, and then choose constiutitve parameters based on the 
material ID. You'll note that the concrete constitutive law is stored in 
a pointer. This makes it easy to extend to support other constitutive 
laws, because you can for example abstract the 
Material_Compressible_Neo_Hook_One_Field class into some base class and 
other classes (maybe a Material_Compressible_Mooney_Rivlin_One_Field) 
and then, based on the material ID, select which constitutive law is 
applied at that quadrature point.
2. The PointHistory::setup_lqp() function is called from 
Solid::setup_qph() 
 
, and more specifically inside a loop over all cells. Its possible to 
retrieve the cell->material_id() or cell->center() (or, if you create a 
quadrature rule to help you then you can get the actual position of the 
quadrature point if you want such granularity). You can then pass this 
information in to PointHistory::setup_lqp() to help decide which 
constitutive law / parameters to apply. If using the material ID then 
you will, of course, want to set the material ID when building or 
reading in your triangulation.


That is, at least, how I typically do things when using this code as a 
basis for extension. I hope that this helps you introduce 
heterogeneities into your problem!


Best,
Jean-Paul

On 26.10.20 08:15, Animesh Rastogi IIT Gandhinagar wrote:

Hello All,

I am trying to solve the wrinkling problem of a thin stiff film 
attached to a soft substrate in dealii. I am using the code - from the 
code gallery for this purpose. For the simulations, I would have to 
consider the film and the substrate with different material properties.


I understand that I would have to do something within the class 
Qudrature point history. However, I am getting a little confused on 
how to approach it. It would be great if someone could help me with this.


This is the code that I am using for this purpose - 
https://dealii.org/developer/doxygen/deal.II/code_gallery_Quasi_static_Finite_strain_Compressible_Elasticity.html 



Thanks!

Animesh

--
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.
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.


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[deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

2020-10-26 Thread Animesh Rastogi IIT Gandhinagar

Hello All,

I am trying to solve the wrinkling problem of a thin stiff film attached to 
a soft substrate in dealii. I am using the code - from the code gallery for 
this purpose. For the simulations, I would have to consider the film and 
the substrate with different material properties.

I understand that I would have to do something within the class Qudrature 
point history. However, I am getting a little confused on how to approach 
it. It would be great if someone could help me with this. 

This is the code that I am using for this purpose - 
https://dealii.org/developer/doxygen/deal.II/code_gallery_Quasi_static_Finite_strain_Compressible_Elasticity.html

Thanks!

Animesh

-- 
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For mailing list/forum options, see 
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--- 
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Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

Re: [deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

[deal.II] Quasi Static Compressible Finit Strain for Heterogenous Hyperelastic material

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