Assignment 2
Objective : To perform the calculations of the given numerical questions and perform 2d/3d meshing of the components as required.
Procedure :
Answers to questions :
1. E = 210GPa ; density = 7.8 *10^-3kg/m^3
Hence v = (E/density)^0.5 = 5188 m/s
2. L = 1000mm = 1m ; v = 5188m/s
Hence t = 1/5188 = 0.1928 ms or 1.928 * 10^-4 s
3. t = 0.1928 ms
4 & 5 : For 20 steps
/ANIM/DT = 0.0001928/20 = 0.000009637625289
Entering these values in the engine file as shown :
6. Already set in engine file
7. Meshing the components :
Housing :
First we will perform the geometry cleanup for the given component.
First we check for any solids. Go to delete-->solids. For this model there are no solids so we do not need to perform this option. Next we go to geom-->defeature-->duplicates to check for any duplicated surfaces. If there are none we may proceed.
Then we will go to geom-->quick edit and toggle all the free edges. If there are any missing surfaces we can fill them up using filler surface option in quick edit panel.
The two components are named as inner and outer.
First we will perform the 2d mesh on both these components using elem size 5mm of only trias. We will toggle all the unnecesarry edges which are too nearby to each other and may fail the minimum size element quality criteria as shown.
2d mesh : Next select the surfaces and click mesh. As we can see the mesh is generated pretty uniformly. We will go to elem cleanup in 2d panel and clanup any elements that maybe failing the quality criteria.
inner component
outer component
3d mesh : After 2d mesh is generated we will generate the 3d mesh (volume mesh).
First go to 3d -->tetramesh parameters and give the tet collapse value greater than 0.15 as shown below.
Next select the inner component, choose the elems, choose the options as given below and click on mesh. Doing so the mesh will be generated in 3d along the volume.
Do the same for outer component as shown.
At the end to check if the mesh has been generated or not go to mask-->elems and choose a block of elems to mask them and see if the mesh has been generated along the volume of the component.
Next we can delete the 2d faces by going to delete-->elems-->2d faces.
Quality check : Next we will check the tet collapse quality check for both these components. Go to tools-->check elems-->3d-->tet collapse as shown below.
As we can see no elements are failing, hence we have successfully meshed the given components in 3d as required.
Arm Bracket :
First we will perform the geometry cleanup for the given component.
First we check for any solids. Go to delete-->solids. For this model there are no solids so we do not need to perform this option. Next we go to geom-->defeature-->duplicates to check for any duplicated surfaces. If there are none we may proceed.
Then we will go to geom-->quick edit and toggle all the free edges. If there are any missing surfaces we can fill them up using filler surface option in quick edit panel.
We will mesh the 4 different parts of this component separately.
Base :
Given elem type as 10mm create a 2d mesh on this surface of the base component. Next go to 3d-->solid map.
Choose the options as shown, choose the bottom surface and click on mesh. As we can see a solid mesh has been generated from top surface to bottom surface.
Arm Curve : Next create a node as shown using the parent geometry of arm curve.
Using the spin option in 3d we will generate the mesh on this part.
Select the elems in the L-shaped section, select x-axis for axis of rotation,select base node, give angle = 90 and enter elems on spin = 28 and click on spin- . As we can see the following mesh is generated.
Arm straight : For this part we will fisrt generate faces for these elems.
We generate the 2d elems for these elems by going to toold-->faces-->elems-->find faces and the 2d elems are generated in a separate collector called faces.
we will use these 2d faces to solid map the entire arm straight part.
Go to solid map and select the 2d faces as elems, select destination geom as end of arm_traight, give density as 12 and click on mesh.
Now we can delete the faces collector.
Boss : Select the top surface of the boss component for 2d meshing as shown below.
Click on mesh. Next go to solid map again.
This time select the elems, dest geom and in along geom option select node path instead and choose the following nodes as shown in the picture and click on mesh. Hence the solid mesh has been generated which is in sync with the arm straight component as shown.
In this way, we have succesffully meshed this component using only hexa elements.
1d elements : Delete all the unnecessary component collectors as shown and mesh both surfaces.
Select a few nodes along the edges to give connectors. Go to 1d-->connectors-->spot and select the nodes,select components to connect, choose type and give spring connection in one place and rigid body connection in the other as shown.
Hence the 2 connections have been made as shown below.
Conclusion : All the questions have been satisfactorily answered.
Result : Google Drive Link
https://drive.google.com/file/d/1f8Is2C5GIj0s8WPSVNH93iAHk9iBiUBS/view?usp=sharing