Crash Worthiness Analysis of Housing and Arm Bracket using Hypermesh Radioss

Crash Worthiness analysis of housing and arm bracket using Radioss Hypermesh

OBJECTIVE

The key objective is to create the 2D and 3D meshing for the given models and solve the following questions

PROCEDURE & Answers

1. Material property for steel we can check in .0000 file. Density is 0.0078 in `g/(mm^2)` and Young modulus is 210000 `g/((ms)^2 (mm)^2`. Here we write units in mm, ms & g because it is given in engine file and we don\'t have to change that file.

By these two given data, we can find the speed of sound `C = root2(E/rho)`.

speed of sound : C = 5188.745 [mm/ms = m/s]

2. Length of the rail is 1000 mm (l) is given.

Time takes for the shock wave to travel from one end of the rail to other is `deltat`
`delta t = l/C` we use this formula for calculating.
we get `deltat = 0.192` in ms`

3. Time for sound to travel the length is 0.192 ms.

4. Termination time is equal to the time taken for the sound to travel the length of the rail which is equal to 0.192 ms.

This we can do by following steps:

View ->browser -> Hypermesh -> solver -> Engine -> Run

5. Now we have to find frequency value which gives us 20 animation file on 0.192 ms runtime

\" No. of animation file = runtime / frequency \"
By using this formula, We get the value of frequency which is equal to 0.009635.

View ->browser -> Hypermesh -> solver -> Engine -> Run

Here we get 20 files by which we can create animation.

These files should be in one folder and path is always same for running animation.

6. charge/print -10: PRINTOUT CYCLE FREQUENCY is -10.

We can see this in run0001 OUT file.

It terminates after every 10 cycles and checks for errors.

7. For 2D & 3D meshing of given models, we have to understand some concepts;
We can do tetra (4 nodes linear tetrahedron) mesh and Hexa Mesh.

Tet collapse is the Quality criteria. It is the ratio. it indicates the height of the tetrahedron element.

We have two files which contain the housing model and arm bracket model.

First, we do for the housing file which contains inside two parts: Cover and Hub.
First, we check for geometry check and if there is no error then we can move on 2D meshing.

We do here Automesh with tria elements and after that, we check for element quality according to question min. and max. length and jacobian, skewness, Warpage, tria angle & quad angle.

We Create 3D mesh in which whole part will mesh and we use here tetra mesh with minimum tetra size of 3 and tet collapse is less than 0.15.
For check wheater all work is good or not we can use check elements option in tools.

We can check whether these both are properly meshed or not. By using the mask/ unmask option. We can see inside mesh elements also.

8. For Arm bracket file, We have four parts in arm bracket.

a) Base part: we do 2d mesh on the top surface of that and use only quad elements with element size 10. After that, we do solid mesh on that by using the element offset option.

b) Arm curve is another part of the arm bracket. Isolate only that part and by the help of Spin option.

c) Arm straight for this we use Linear solid option. For creating linear solid, we required source elements and destination elements in 2D not in 3D. While using Linear solid option be Cautiously attentive while giving alignment to nodes on both the faces it should be in proper order.

d) For the Boss part: We use Solid map option. Here we also require destination geometry and proper element size.
When we use Solid map for 3D mesh it will create separate PID by its name \'solid map\' . So we have to move that 3D mesh from solid map PID to Boss PID and \'Make current\' to the boss.

Here we use 3D Hex mesh.

We can check also whether 3D meshing is proper or not by using the mask/unmask option.

CONCLUSION

• We get to know how to make animation in Hyperview.
• Also, create animation files, know about data file & engine file for creating animation and get to know how it works.
• Create 3D volumetric mesh in given models with proper mesh flow.
• Learned many options which are very helpful for the 3D mesh and contour option in Hyperview.

Google Drive Link for all files

https://drive.google.com/open?id=1UpA6N2c6YbqZ3wn1GLg_DcsQjVOG3f0M