Performed 2D and 3D mesh of Housing and Arm bracket in Hypermesh

Objective:

• Solve given question
• Perform 2d AND 3d meshing of Housing and Arm bracket

Questions:

1. Check the material properties of the rail component and calculate the speed of sound in steel rail=_______

2. The length of the rail is about 1000 mm.calculate the time takes for a shock wave to travel from one end of the rail to the other.

3.Time for sound to travel length of rail=______

4.Edit the engine file so that the stress wave can be monitored, moving from one end of the rail to the other during impact -this will require a termination time equal to the time it takes for the sound to travel the length of the rail(set on/RUN card)

5.Set the frequency of animation output to a time that will give 20 animation steps(/ANIM/DT)

6.Change /print -10.

7.3d meshing tetra mesh and hex mesh

• Repeat class examples and, maintain the quality.
• Target tet size=5mm,hex size=10mm,tet collapse=0.15.

Solutions:

1. From the file FIRST_RUN_0000.rad , we can find properties of materials such Density= 0.0078 and Elasticity=210000. The units are in mm, ms as given in Engine file. Speed of sound in steel rail is

`sqrt E/rho`

= `sqrt 210000/0.0078`

= 5188.74 mm/ms

2. Given length of rail is 1000 mm , c= 5188.74 mm/ms

time takes for a shock wave to travel from one end of the rail to the other is

Δte = l/c

= 1000/5188.74

= 0.1927 ms

3. Time for sound to travel length of rail= 0.1927ms

4. As we calculated time taken for sound to travel length of rail is 0.1927 ms

Steps: Import FIRST_RUN_0001.rad solver deck>view>solver browser>ENGINE_KEYWORDS>RUN

5. The frequency of animation output to a time that will give 20 animation steps(/ANIM/DT) is calculated as:

Run time/No. of animations

=0.1927/20

=0.009635 ms

Steps: Import FIRST_RUN_0001.rad solver deck>view>solver browser>ENGINE_KEYWORDS>ANIM>ANIM/DT

6.Change /print -10: Printout cycle frequency is -10

7. Procedure of 2D and 3D mesh of following models:

(i) HOUSING:

• Import CAD model by selecting Optistruct or RADIOSS as user profile
• Model consist of Hub and Cover perform meshing individually.
• For this model TETRA 3D mesh is to be performed so make sure to mesh the model firstly with TRIAS only in 2D. Give element size 5mm for 2D meshing
• After performing 2D meshing, go for TETRAMESH in 3D by using parameters given to us element size 5mm min 3.5mm max 7mm
• After performing TETRAMESH make sure to check for tet collapse 0.15 in element check in TOOLS. Make sure there are no tet collapse in model
• Mask few elements to check TETRA elements

(ii) ARM BRACKET:

• Import CAD model by using Optistruct as user profile
• Model consists of 4 parts:

1. Base part: First 2D meshing is done with QUADS only element size 10. After 2D meshing go to 3D do Element offset make sure to calculate thickness
2. Arm curve: For arm curve, spin option is performed . Make sure to take circle centre and select elements properly. At the end delete all the 2D elements
3. Arm straight: For Arm straight, Linear solid option is used. Faces is created for 2d elements at face and create 2d elements at destination face. Make sure number of nodes and elements of source and destination are matching totally. Make sure to delete all 2D elements at the end.
4. Boss: For Boss, solid map is used. One circular face of boss is meshed with same number of nodes in order to have QUAD elements. After creating 2D quads, make sure to project and duplicate node at the end so that all the elements can be make from one end to other. Select Destination surface use mixed option to select node by path and line between source and destination surface. One component with name of Solid map is created make sure to organize all elements from it to boss part .

Conclusion:

• All the questions were answered learned how to get data from rad file
• Performed 3d TETRA AND HEXA elements successfully