Assignment 1-2D Meshing Challenge

OBJECTIVE

The objective of the challenge is to carry out the 2-D meshing on the given geometric model and assigning

proper thickness by using generic property

* practice

*clip repair

* mounting bracket

first the objective is to obtain a geometry that does not have any free edges . that is to convert all the

respective geometries into refined one .

next to clean the geometry

next to that is to extract the their midsurface

to create a 2-D mesh the midsurface is to be cleaned

to create 2-D mesh with target lengths 5 mm (min 3.5 -max 7mm)ignoring the holes less than dia 5mm

and to assign thickness by creating a generic property .

CASE SETUP AND EXECUTION

geometry 1 :

from the given question the model was first downloaded

the initial step carried out was importing the model (import >import model )

next the geometry was made to fit in the graphics screen

the model was switched to mixed mode and then viewed for free edges

the edges that needs to be toggled are toggled using (geom >quick edit >toggle line )

the lines that needs to be filleted are done using filler line (geom >quick edit >filler line)

and a extended surface was trimmed by deleting the surface (surface edit )

next the lines that are connected to three surfaces are clered using delete

now the cleaned geometric surface is ready to extract its midsurface

now hitting midsurface select the closed geometry hit extract

now we obtain the midsurface .

now selecting the surface having four holes less than dia 5mm to get rid of that first remove the unwanted

points (geom >quick edit >add/remove points )

now filler the four holes and toggle the holes .now the holes are removed

now carrying out the meshing process by hitting with element size 5mm (2d > automesh >surfs > mesh )

and then meshing is carried out in the similar way by hitting automesh

the no. of elements are adjusted according to the quad elements

the fillet surfaces are meshed with 2 elements

the curved edges are meshed by first splitting using (geom > quick edit >surface split node )

now it is meshed .likewise the most of the geometry is meshed

and now the surface has larger hole .

so to obtain a proper mesh use washer split

now the surface is meshed and remaining is meshed too .

now creating a property on the model window select the card image as PSHELL and click ok

assigning thickness as 1.8

now the geometry is totally meshed .

geometry 2 :

import the given geometry , then it is switched to mixed mode

then the geometry has splitted nodes so using the replace points the point were joined

now the geometry was closed .

by hitting midsurface surfs it is extracted

here the corner of the surface is not joined ,using the key F11 selecting replace points they are joined

now the midsurface is cleaned up .noe it is ready to mesh

selecting the top surface for meshing with element size 5mm the hole was subjected to washer split of 3mm

the washer surface was meshed and the no. of nodes were made equal to achieve quad elements

now select elements and again mesh it up .it provides a better shape

check for "keep connectivity "

mesh the fillet surface

now to mesh the side surface get rid of holes less than 5mm

using remove points and filler line and toggle line tool as like the previous geometry the holes are removed

now it is meshed .then the next side fillet surface is meshed like the previous one

then the other side surface is meshed and the horizontal side panel is also meshed by getting rid of the holes

as the other two are the mirror images of these two ..using the position tool (tool>position>elements

>nodes).

by selecting elements and duplicating them ..then fixing the nodes from where it is and where to ,the mesh is

moved .

by using 2d > smooth the elements are smoothed for 10 iterations. now the meshing is completed .

then create property on the model window assign thickness as 2mm ,card image as PSHELL.

it can be viewed through 2D detailed element representation .

geometry 3 :

download the geometry

import the geometry

the geometry when switched in mixed mode was completely closed without any free edges .

so extract the midsurface by hitting geom > midsurface > surfs >extract

now to carry out the meshing first on the top surface and arms of the mounting bracket get rid of holes less

than 5mm.

by using the tools remove points and filler line and toggle line

now to mesh the curved edges for good oriented mesh split the surface using geom > quickedit >surf split

node

now mesh the top surface and the curved edges ,smooth the elements ,also again mesh the elements by

selecting them .

to mesh the arm hit automesh complete meshing one by one . now the other three are the mirror images of

first one using tool>position >elems>nodes ,select elements and duplicate them and by fixing nodes move

them , the geometry is meshed .

by creating property on model window and assigning the thickness as 9.1 the generic property is assigned .

now it can be viewd through 2D detailed element representation .

IMAGES

the images of steps carried out and tools used are uploaded .

RESULT AND CONCLUSION

the challenge enable us to operate the tools of 2D meshing .

all the three given geometries are meshed and the thickness was assigned to them .

all the steps are followed properly .

it allows to practice 2D meshing which is a basic of upcoming steps

the geometries are meshed through cleaning the surface ,extracting midsurface ,

midsurface cleaning , 2d meshing .

MODEL

the meshed models are uploaded.