Hi everyone,
First little bit of background over my model.
My model is 3d,deformable solid extrude and consist of grephe flakes each flakes depth is 0.33 nm and length we can input,We can input the total box size in nm ...no of layers in that box...and the size of flakes...and the layers are generated automatically with no pattern.And Both side are supported with support.And one side is fixed and another is provided with displacement load.The element is 4 node linear terahedron.
target
we trying to implement cohesive behaviour in the model and we have created a code that defines cohesive behaviour between the graphene flakes,The cohesive behaviour are obtained from the molecular dynamics simulations AND also want to find the modulus of elasticity of grephene from the stress and strain curve.
I think the value of E should not depend upon the no of layers and on the displacement we provide but i didnot receive exact value.I have summaried the value below
implications.
not able to find the drop in the curve as in case of pure cohesive behaviour whre the tensile stress deteches the cohesive bonding between layers.
The full analysis is not complete.For some layers 0.3..for some layers 0.8 and so on and i have found the stress and strian from the values of incomplete simulation.
Only the linear and sometime nonlinar force displ curve is obtained but never the force value drops to 0 as in the case of pure cohesive behaviour.
is my analysis or results ok or is there problems in my concept.
my thinking.
we cannot implement cohesive behaviour in this model because if there are no of layers we have to pull at least one layers from no of layers to implement this behaviour but i have pulled all the layers.
Due to automatic generation of the flakes there will be some non symmetricity and unconnected regions betwwen the flakes and the value of E for different layers are different.
Suggestions
| summary | |||||||||||||||
| Total box size | 100 | no of layers | 40 | size of flakes | 30 | load 1 | E=1.37e9 | load 0.1 | E=1.71e9 | 4 unconnected regions | |||||
| Total box size | 100 | no of layers | 35 | size of flakes | 30 | load 1 | no result | load 0.8 | E=1.08e9 | load 0.5 | E=1.08e9 | load 0.1 | E=1.07e9 | no unconnected regions | |
| Total box size | 100 | no of layers | 30 | size of flakes | 30 | load 1 | E=1.3e9 | load 0.1 | E=1.42e9 | 4 unconnected regions | |||||
| Total box size | 100 | no of layers | 20 | size of flakes | 20 | load 1 | E=1.34e9 | load 0.1 | E=1.88e9 | 3 unconnected regions | |||||
| Total box size | 100 | no of layers | 15 | size of flakes | 15 | load 1 | E=1.23e9 | load 0.1 | E=1.29e9 | 4 unconnected regions | |||||
| Total box size | 100 | no of layers | 10 | size of flakes | 10 | load 1 | E=1.9e9 | load 0.1 | E=1.96e9 | no unconnected regions | |||||
please experts suggest me some valuable ideas or logic or opinions.