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AnimeshAnimesh 

Impact analysis of Graphene reinforced Polyurethane nanocomposite using Accelrys Material Studio 7

I am doing PhD ( mechanical engineering ) on impact analysis of Graphene reinforced polyurethane nanocomposite using Accelrys Material studio 7. For impact analysis constraint is very very important. Can anybody discuss various type of constraint used in material studio???when we used atom,length and lattice constraints??? During impact analysis is it possible to give velocity on the impactor or striker in material studio????
Best Answer chosen by Animesh
CarstenCarsten (Accelrys) 
This should be possible:
  1. Build Graphene starting from Graphite.
  2. Optimize a and b vector with the method you want to use, fix c and the angles.
  3. Build the Graphene superstructure you want to use.
  4. Add enough vacuum space to the model.
  5. Build and optimize the cluster you want to impact onto the Graphene layer.
  6. Add it at 6-7\AA on top of the Graphene onto which you want to fire it.
  7. Do a 1step MD with the method you want to use at the temperature you want to use. this is just to get the velocity property for the atoms.
  8. Download the results.
  9. Select the added atoms and edit the relative velocity of he added atoms and set it to a velocties that way that they fly towards the Graphene layer (typically, x,y=0 and z to a certain value).
  10. Do an NVE run with Current velocities.
The attached *.xsd file should be hopefully be ready to be used in an NVE run with velocities set to Current in Materials Studio 7.0.

The trajectory of the complete run (Cl2 as the molecule to which the velocities wre assigned) is too large to be attached and was done with DFTB+ in Materials Studio 2017.

All Answers

CarstenCarsten (Accelrys) 
I doubt that impact studies are feasible because this might be on a completely different length scale. Or what do you mean with that?

Although, this is not done with Forcite+ I think that this is an interesting starting point:
http://9pesxm.chemeng.ntua.gr/fullpapers/MP0256.pdf

With PU ans the possible ring spearing it might be a but more difficult to build the system using Amorphous Cell but let's see.
AnimeshAnimesh
I have seen some paper where impact analysis of Graphene is done by Molecular dynamic simulation . In this paper cluster of silver atoms hit graphene layer. Some constraints are given to silver atoms as well as graphene.Then some energy is given to silver atoms to move toward graphene. Can anybody discussed about impact analysis using Accelrys Material studio (Molecular dynamic simulation )
CarstenCarsten (Accelrys) 
This should be possible:
  1. Build Graphene starting from Graphite.
  2. Optimize a and b vector with the method you want to use, fix c and the angles.
  3. Build the Graphene superstructure you want to use.
  4. Add enough vacuum space to the model.
  5. Build and optimize the cluster you want to impact onto the Graphene layer.
  6. Add it at 6-7\AA on top of the Graphene onto which you want to fire it.
  7. Do a 1step MD with the method you want to use at the temperature you want to use. this is just to get the velocity property for the atoms.
  8. Download the results.
  9. Select the added atoms and edit the relative velocity of he added atoms and set it to a velocties that way that they fly towards the Graphene layer (typically, x,y=0 and z to a certain value).
  10. Do an NVE run with Current velocities.
The attached *.xsd file should be hopefully be ready to be used in an NVE run with velocities set to Current in Materials Studio 7.0.

The trajectory of the complete run (Cl2 as the molecule to which the velocities wre assigned) is too large to be attached and was done with DFTB+ in Materials Studio 2017.
This was selected as the best answer
AnimeshAnimesh
Very very thank you Carsten.Your answer have given me a great relief from research tension. Kindly give similar  step for impact analysis of some Iron (Fe) atoms hitting Graphene reinforced Polyurethane nanocomposite.
1. How to develop 0.1%,0.3% ,0.5% and 1% ( weight%) Graphene reinforced Polyurethane nanocomposite???Can I use amorphous module..construction option...density... 1.3 gm/c.c (nanocomposite experimental density value) ,Density of polyurethane 0.9 gm/c.c 
2. How to develop Fe atoms hitting Graphene reinforced polyurethane nanocomposite??? 
If possible to send the you tube video of that tutorial in my email : animesh_talapatra@yahoo.co.in
CarstenCarsten (Accelrys) 
I am still not sure if this will work out properly and if we are on the same length scale.

At least in theory once you have the graphene model it can be used in an Amorphous Cell Confined Layer task.
By changing the number of graphene models in the build one can generate systems with different graphene concentrations and one needs at least 3 graphene models in the system I would say.

The problem I see is that we might suffer from ring spearings and that it might not be that easy to build the system.
The real problem is that with such low graphene concentrations the systems are simply too large to properly handle them and I doubt that this can be done in a reasonable amount of time.

The Cl2 system simply has to be replaced by a Fe atom if just an atom is needed
AnimeshAnimesh
I am confused one matter in amorphous cell construction.There is two term loading and weight fractions.what is relation between them???How they are related to volume faction of fiber and matrix. What will be answer if I want to mix 1% Graphene in polyurethane matrix???What will be loading to prepare graphene reinforced polyurethane nanocomposite???? Kindly clear this matter in amorphous cell construction . 
CarstenCarsten (Accelrys) 
You get this when clicking the Help button for the Amorphous Cell Setup:

Composition

Molecule: The 3D atomistic document (.xsd) containing a nonperiodic structure of a single molecule.

Loading: The number of molecules per cell (for the Construction and Confined layer tasks).

Mole Ratio: The number of molecules of this component relative to the total number of molecules (for the Packing task).

Weight %: Read-only property reporting the weight
percentage of this component in the total composition.

By having a different number of graphene models (molecules) you can change the weight%.

The volume fraction can only be estimated. For what do you need it?

To which percentage does this refer:
What will be answer if I want to mix 1% Graphene in polyurethane matrix???
AnimeshAnimesh
Can I say single layer graphene = 1%(weight %) of Graphene ,Double layer graphene = 2% (weight %) of Graphene and three layer graphene =3% (weight%) of Graphene. Can I add  single layer amorphous  cell construction  1  %  (weight %) GRAPHENE reinforced polyurethane nanocomposite ????
AnimeshAnimesh
Molecular dynamic simulation  of Polyurethane (trade name Vibrathane B836) is done by Accelrys Material Studio 7. Vibrathane B836 is  combined of  polyether-based Diphenylmethane Diisocyanate (MDI: 4, 4'- Methylenediphenyl Diisocyanate) and 1, 4- Butanediol. The model has 50 chains in total where each chain consists of  four urethane hard segments, four polyether soft
segments, four urethane hard segments, four polyether soft segments, and four more urethane hard segments  to represent realistic PU. The initial model is built by the amorphous construction at room temperature (298 K) with a density of 0.85𝑔m/𝑐.c (experiments 0.97 − 1.24 𝑔/𝑐c). The energy minimized using the Discover module in Materials Studio 7  in total time step 5,000 fs with a 1fs time step. NPT ensemble at 1 atmosphere and 298 K for 500,000 fs with a 0.1fs time step. Annealing   is done  600K with a 25K  increment (100,000 fs  run with a 0.1 fs time step for each 25K) to cool down to room temperature. NVT ensemble is run for 100,000 fs with a 0.1 fs time step. Density obtained through the simulation was 0.95 gm/c.c. I have developed Polyurethane unit cell.Now how to develop various weight %  graphene reinforced polyurethane nanocomposite.
CarstenCarsten (Accelrys) 
All these steps have to be redone for each graphene weight% concentration and I would guess at least 10x for each concentration to get a statistic for the orientation of the graphene models (at least 3 models) in the system. At the end I do not know how many different configurations are really needed.

At least in theory. I did not check if the current system size is sufficient to get the wanted weight% for the graphene model
AnimeshAnimesh
I am sending three paper as attachment on impact analysis. In my PhD ( mechanical engineering) work, i have a intention to do similar simulation.Kindly guide to run similar simulation. I am facing the problem that giving velocity on striker, it is not hitting the object.How to set striker above surface within in a crystal???
AnimeshAnimesh
This paper giving penetration of surface after hitting. I am unable to generate this type of simulation.Here it is showing graphene surface are broken after impact.How it is possible to run??? 
CarstenCarsten (Accelrys) 
Please do not post papers that might be illegal.

Both papers use AIREBO as force field..

Please search on http://references.accelrys.com for AIREBO and check what was done in those papers.

If you need bond breaking the only option I see is to use GULP using the reactive forcefield (to see if your or AIREBO (I do not know if that force field can be used for your system) but in Materials Studio 7 things are somewhat limited here from what I remember.

As I do not know AIREBO and which potential functions are used I do not know if they are covered by GULP in Materials Studio 7.0

I tend to say that they are not in there.


I still think that your system may be to large for this.

Do you have GULP licensed?

 
AnimeshAnimesh
AIREBO force field is not available  but Tersoff force field available.Can I do using Tersoff??? or other option???Kindly write down the steps one by one to run the simulation
CarstenCarsten (Accelrys) 
The Tersoff potential which come Materials Studio GULP do not have all elements you need C, N, H, O and I also did not find them so far but I did not search that long.
AnimeshAnimesh
Actually I have to do impact analysis using Accelrys Material Studio 7.0. So any how  have to analysis using this version. Kindly give me suitable module name and force field to do research work.
AnimeshAnimesh
Molecular dynamic simulation problem may be divided into two types (1) Non reactive force field problem and (2) Reactive force field problem.When there is impact analysis problems  ( bond breaking is essential ) that is reactive force field is very essential. I  have got some information about reactive force field like AIREBO,REAXFF using Gulp module. Can any body give me more information about reactive force field and module for bond breaking operations???
AnimeshAnimesh
Impact analysis problem using reactive force field (bond breaking purpose),most of MD experience persons are strongly advised me to do MD simulation in LAMMPS in this purpose.But i am not interest in LAMMPS. I love this Material studio to do my research work in this purpose.Kindly help most experience persons in Material studio this type of research problems  (reactive force field  i.e.bond breaking purpose).I am waiting for any helpful person. 
CarstenCarsten (Accelrys) 
If ReaxFF is needed Forcite is not an option. Only in Materials Studio only GULP has ReaxFF but with the system size you need (I think) these runs may take ages.