Aim :-

• To edit the Engine file and 3d meshing the given components.

Procedure:-

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

From the "FIRST_RUN_0000" we can get the values of steel material is ,

Young's modulus of material is 210000.0 = 210GPa

Density is 0.0078 which is equal to 7800 kg/m3

we know that, Speed of sound in the material is (c)

`root`(E/D) = `root`(210GPa/7800) = 5188.74m/s or 5188.74mm/ms

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

Time takes to shock wave to travel 1000mm = L / c

Where, L is length of rail

C is speed of sound in material

= 1000/5188.74

t = 0.192725ms

3.Time for sound to travel the length of the rail.

Time taken by the sound in the material medium = 0.192725ms

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).

First, I have imported the FIRST_RUN_0000.rad by import solver deck option. Engine file is FIRST_RUN_0001.rad.

Now, in the solver we can edit the values of the Engine run time by clicking on the ENG_RUN and changing the value to 0.1927.

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

To get the 20 animation frames we have to change the Tfreq in ENG_ANIM_DT as,

Animation steps = 20

Run Time = 0.1927

= 0.192725ms/20

=0.00963625

In the out folder we can observe the number animation file are reduced to the 20. Animation files are with the name “FIRST_RUNA000”.

The final edited Engine rad file is,

6.Change /print -10.

We can change the Print value to -10. It means it will print the values for every 10 values while the solver is running.

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.

Procedure –

Step 1 : importing the given STEP file into the hypermesh.

Step 2 : After checking the geometry and doing the edits. Go to 3d panel and choose the Tetra mesh > Volume tetra > select the 2 solids in the model. Set the element size as 5 and click on mesh.

Step 3 :- We can get the tetrahedral mesh as shown in the image. We can observe the mesh flow by using the mask feature.

2. Arm Bracket Model.

Step 1: Importing the given STEP file into the hyper mesh.

Step 2: meshing of base component

• First 2d mesh on the top surface by using the automesh.
• Next by using the element offset method we can mesh it in 3d.

• By this we can create the hexa elements mesh for base.

Step 3: meshing the middle components

• We can use the spin option in 3d meshing for that create a base node by using the circle centre option for the arc.
• Set angle to 90 and on spin to 25.
• Click on Spin-, Hexa mesh is created.
• For, meshing of other part we can use Linear solid in 3d panel.
• We need to have the same number of elements on both the surfaces for that.
• Select the from and to elements. Alignment of nodes on both surfaces.

Step 4: meshing of bose component.

• First mesh the top surface by using the automesh. Edit it for good mesh flow.
• Now use the solid map tool for 3d hexa mesh. Before project the nodes on the on the components to maintain the connectivity of two components.
• delet the all the 2d meshing faces that we have created while meshing by using the delet faces option.

Final CAD Model image.

Objectives of learning from the Assignment :

• Learnt using different options in 3d panel of hyper mesh for 3d meshing.
• Editing of Engine file of Radiosis solver.
• Equations of shock wave traveling in the materail medium.