load transfer in grephene laminates

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 size100no of layers40size of flakes30load  1E=1.37e9load 0.1E=1.71e94 unconnected regions                    Total box size100no of layers35size of flakes30load 1no resultload 0.8E=1.08e9load  0.5E=1.08e9load 0.1E=1.07e9no unconnected regions                Total box size100no of layers30size of flakes30load 1E=1.3e9load 0.1E=1.42e94 unconnected regions                    Total box size100no of layers20size of flakes20load 1E=1.34e9load 0.1E=1.88e93 unconnected regions                    Total box size100no of layers15size of flakes15load 1E=1.23e9load 0.1E=1.29e94 unconnected regions                    Total box size100no of layers10size of flakes10load 1E=1.9e9load 0.1E=1.96e9no unconnected regions    

please experts suggest me some valuable ideas or logic or opinions.