Week - 4 - 2D meshing for Plastic components

• AIM :-

• To extract the midsurface and perform geometry cleanup for the giving plastic bottle cap model and mesh the same with giving element quality criteria as mention below and assign a proper thickeness to it.

• Objective :- * All the 2D elements should clear the given quality criteria except near to tiple cons or at smaller regions.

S.No	Quality Criteria	Value
1	Target/Average length	1
2	Minimum Length	0.5
3	Maximum Length	3
4	Aspect	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
10	Tria Percentage	15

* Extract the midsurface of given plastic model accurately.

* featured are capture properly with good mesh flow in model.

* Assign the proper thickness to the midsurface af all components.

• Procedure :-

*import the given model :

*First we import the model in ANSA( file – open – select file – ok )

* check the geometry :

* For check geometry we check one by one all components seperately.

( Tools- checks -geometry )

* If error are show in check manger we have to fix it.

* Some error are clear by ANSA and some which can not clear by ANSA that error are cleared manaually.

In this model we found 1 error which is fix by ANSA.

In this way we check our geometry and clear the issues.

* After that, we can go ahead and change the cons resolution by accessing the mesh module and selecting 'length' in the perimeter section. we wiil then need to select the

whole model and assign a 1 mm length.

*Extraction of Midsurface :

* for mid surface first we check the component and its thickness. for this we use measure commant. ( utility - measure )

* The given model is plastic components and so it have non uniform thickness throught the component we can in adove iamge.

* Given model is plastic component and have non uniform thickness ,we use manual method for extraction of midsurface for this model.

* For extraction of mid surface we use different , different tools and apparoaches.

We use offset tool for extraction of mid surface which are uniform and plane in any one of it's side.

* As we can use offset option.( Topo – faces – offset ).

* we use middle tool for extraction of mid surface for those surface which are uniform in both the sides.( Topo – faces –middle )

* in above image we can see that how easily we extract the mid surface for this ribs type of surface which have uniform surface both side.

* we can curve middle tool for extraction of mid surface such as thread and rids of small surface.( Topo – curves –middle)

* After the creation of middle curve we project this curve to base mid surface and create the new surface and in this way we get mid surface of such complicate surface.

( Topo – cons –project)( Topo – faces – new – cons)

* We use faces offset tool for extracting mid surface of teeth . After this we extent this surface to the base mid surface.( Topo – faces –middle)( Topo – faces – extend)

* As we can see in above image we take a midsurface of one teeth and then for other teeth we can translate tool and rotate the extracted mid surface for all the teeth.

*For translate we the mid surface pf teeth we have to creat 2 cog points.

* For those surafaces which are not connect with base mid we use extend tool and also we use intersect tool for creating tool for creating t connection.

*After extract midsurface for whole component we have to check the mid surface thorgh comparing with parent geomtry. we use transperancy option ,we go to property and on transpency of parnet model property and compare it with newly generated mid surface.

*Create property and assign thickness:

* After taking the midsurface of all the surface we have to create and assign the property thickness according to the parent model thickness.

( Faces – setPID – Select the entity and create new id – Pshell – mention –thickness – ok ).

* As we can see that in above image , we segragate the surface in different - mid surface and parent geometry .

• Mash Generation with quality paramaters :-

* First of all we set the orient for the model so that our element are in same face/ noraml

* Before start meshing we have to set the given quality criteria and mesh perimeters.

- 2D mesh generation :

- we mesh all the components one by one.

* First we set the perimeter length as 1, according to the target length for all the components.

( mesh – perimeter – length – target – element size)

- check the geometry and do appropriate topology cleanup.

* we chesk the geometry where element are failed for minumum length and then we take appropriate action such as toggling the cons.

( mesh generation – spot mesh – selecting surface –mesh ).

* For generation the better mesh flow we have to aviod the trias at the bassis on aviod the trias which are forming opposit to each other.

aviod the trias ,near fillet regions.

aviod the trias, near the cricular holes.

aviod the back to back trias.

which will effect the results of the model and these can handling by some tools such as split and swap.

*we use reconstrruct tool to clear trias and get better mesh flow.

* we use split tool to get rid from trias element and opposite trias.

* we use the smooth tool option fot better arrangtement of element.

* we use th hidden mood mode of drawing style to see quality of elements.

* we use move tool for clear the element quality

* we use paste tool for the tria remove the tria element.

* In order to see the thickness of the component go to the utility- quality - on the draw shell as a soild - on and in the below image we can see the thickness of the component.

• complete meshed model.

* in entity mode

* IN PID mode

Learning Outcomes :-

* Understood about extracting mid surface of plastic components.

* lear how to extract mid surface mid surface of complicated surface such as tooths and threads and tibs.

* learn diffent tools and techniques for clearing the quality of element and improve mesh flow throught the whole component.

Results :- the mesh is obtained significate on given model with requried quality criteria.

conclusion :- learn different tools and techniques and understood how to mesh tha plastic components. the given model successfully meshed with proper thickness assining.