Week - 4 - 2D meshing for Plastic components

Name Of tool test :-

Bottle caps.

*objectives:-

To remove all topological errors, creating the mid surface and meshing the component with given quality criteria.

*methodology:-

1)geometry cleanup

2)generating mid surfaces

3)assigning relevant pid

4)meshing as per given criteria.

1 geometry cleanup:-

first of all model created by design engineer based on requrement but that engineer is not understand about this model is good or bed then ansa software required for the check the quality criteria.

• For that first of all import a file of bottle caps
• After that change the perimeter length to 1 mm. this opction is available at mesh>perimeters>length
• This change is required for better(fine) geometry.(seen different between fig 1 & 2)

For remove topological errors we use topo opction and it select for all over geometry. if we topo opction selected then full geometry is remove the geometrical error ike two single cons(red line) are connected and convert to double cons(yellow line).

For remove errors like triple cons, single cons, cracked faces, needle faces using the geometry. this opction available at tools>checks>geometry. The remove this error using autofix opction, if we use auto fix opction then some time not remove error that time we remove this error use of mannual.(note:- most of triple cons error are not remove and another error ae removed) .

2) generating mid surface:-

Manual mid surfacing for some surface use of offset opction and some surface use of middle opction.

offset:- topo>faces>offset

middle:- topo>faces>middle

there are two face available of any surface. the one side surface is negative value and another side of surface is positive value. for this reason ansa provided two color of surfaces.

i)gray:-

if we choose gray face for offset then put negative value of half of the thickness.

ii)yellow:-

If we choose yellow face for offset then put positive value of half of the thickness.

in this figure we see that the one side of surface is yellow and another side is gray, and this condition is apply for evry surfaces.

after the create mid-surface of the model:-

3)assigning relevant pid:-

After the mid surfacing we create new pid of mid surface.

for that use topo>faces>set pid.

after thas choose new pid opction and we provided name and thickness and provide another setting just like color editting and select ok button then create new pid.

after that we convert entities mode to pid mode then model show like this.(below fig)

4)meshing as per given criteria:-

first off all change perimeter length to 5 mm from the 1 mm, because our targeted length is 5 mm.

put different value of quality criateria available is under.for open quality criteria window use f11 short-cut key.

Number	Quality criteria	Value
1	Targeted/average length	1
2	Minimum length	0.5
3	Maximum length	3
4	Aspect ratio	3
5	warpage	15
6	skewness	45
7	jacobian	0.7
8	Minimum quad Angle	45
9	Maximum quad Angle	135
10	Minimum tria Angle	30
11	Maximum tria Angle	120
12	Tria percentage	15

we also value put in the mesh parameters.in mesh parameters there are three values are most important:-

1) target length(average)

2)minimum target length

3)maximum target length.

use the best mesh command for the entire part(mesh>mesh generation>best). we seperate the components in to several parts for best results .

after that use reconstruct, smooth to achieve proper mesh flow.

if there are more triangular mesh available then we another opction choose like swap, joint, split(hybride opcion) and decrease the tringular mesh and then improvement of our result.

5. Assign thickness to mesh :-

After meshing we have to assign thickness to mesh by going in the property menu. here since we have varying thickness throughout the geometry, thickness will be different of each part.

Conclusion :

Mid-surface of component is achieved by using different type of manual midsurfacing method and the component is meshed according to given quality criteria.