Learning Forum

[Suren Malumyan]

Hi Everyone!

 

Please, can somebody explain?

Is it possible to keep some matrix space between reinforcement bar (smeared or discrete) and mesh outline?

The example is shown in the figure.

[Dave Looman]

Probably not, but you could see if /shrink,0.1 makes the display easier to interpret.  I think this will do the opposite of what you want though.

[Suren Malumyan]

Hi Mr. Dave Looman,

Thank you for the response,

I just need the bar's length to be smaller than the mesh's one, because I want to model nanotubes in the cement matrix,

 

So, how can I model this composite?

 

[Dave Looman]

So it's not a graphics issue, you don't want the reinforcement to be terminated inside the element?  For that you will need to create thin, unreinforced elements between the reinforced elements.  You can imagine that a finite element shape function couldn't support a discontinuity like reinforcing starting and stopping inside the element.

[Suren Malumyan]

Understood, but in that case how can I add those thin elements in the beam?

I want to model CNTs (Carbon Nanotubes) in cement beam. CNTs are nanoparticles distributed within a matrix.
 
There is examples from some articles where authors used these particles in composite specimens by using Ansys.
The example is shown in the figure below.

 

 

Regards,

Suren Malumyan

[Dave Looman]

You would need to slice up the geometry so you could mesh the unreinforced domain separately.

[Suren Malumyan]

Like the beam mentioned in the figure?

I did it by other program,
By the way how can find this type of meshing in APDL?

[Dave Looman]

APLD geometry creations is documented in the APDL Modeling and Meshing Guide.  The approach I envision is to create the entire domain first with the BLOCK command and then slice it up with VSBW (Volume Subtract Work Plane).  The location of the work plane is specified with the WPLANE command.  After you have an initial position for the workplane it's easier to move it the next location with the WPOFF command.  After you made the slices in one direction you would specify a new rotated workplane with WPLANE.  So the commands would be:

/PREP7

BLOCK,...

WPLANE,...

VSBW,...

WPOFF,...   ! Repeated commands could be in a *DO loop

VSBW,...

WPOFF,...

VSBW,...

WPLANE,...      ! Rotated workplane

VSBW,...

...