Assignment 2-RADIOSS Engine File Editing & 3D Meshing Challenge

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

Ans :

Young modulus of steel : 210,000 N/mm² and dencity : 0.0078 gram/mm^3

the formula for speed of sound wave in material : sqrt(E/Rho)

Sqrt (21000/0.0078)

Velocity of sound wave in (rail material) = 5188.7452 mm/ms or M/s

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

Ans : Length of the rail = 1000 mm
speed of sound wave = 5188.74 mm/ms

time required for shock wave to travell one end to other end in rail : 1000/5188.74 ms = 0.192 ms

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

Ans :

as the length of rail is 1001 mm , and velocity of sound in same material is 5188 mm/ms ,

Time required to pass the component : 1001 / 5188 = 0.1929ms

so we can assume the the sound wave pass the rail in 0.1929 ms.

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)

Ans :

Open first_run_0000.rad file in hypermesh > radioss solver

now go to solver under tree diagram.

Expand ENGINE_KEYWORD

EXPAND RUN> RUN > ENG>RUN

change Tstop = 0.19296

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

NOw EXPAND ENGINE_KEYWORDS
EXPAND> ANIM > ANIM/DT > ENG_ANIM_DT

as we wo anumation step divide 0.19296 into 20

T freq = 0.009648 ms

6.Change /print -10.

Expand ENGIINE_KEYWORD
EXPAND PRINT> PRINT> ENG_PRINT

Set value as -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.

Procedure :

Objective:

To mesh the given file and connect it by any one 1D connector

Steps:-

• Directly open the .hm file into the software
• Mesh both the surfaces

• Go to 1D>connectors>rods select any two nodes to connect,
• Now the connection is done , after which new property card should be assigned to the component with property card image of "P2_Trus"
• New hyper beam has to be created , go to hyperbeam and select required cross section and give the required dimension as shown below

The final result is shown in below image

Steps for 3d tetra mesh model:-

• Open the model directly since it is in .hm format

• Check for any geometrical error, in this case we dont have any so carry on with 2d mesh first
• Mesh the each components according to the given quality criteria with tria elements

Now we have to convert the 2d mesh element to tetra elements by 3d>tetramesh select the elements and mesh with required tet collapse value

Do the same to the other components and make sure no tet collpase errors should be present

Steps for 3D hexa mesh 0f arm bracket model:

• In this model we have four components , one by one we will be meshing the model
• We have different methods to perform 3d hexa mesh like Element offset, spin,Linear solid, solid map...etc
• We will be using these methods to perfrom hexa mesh on each component, depending upon the components geometry
• Firstly the base , it is just a rectangular cube it is better to mesh the top surface with only quad element and use element offset option

Next component is curved arm, to mesh this model select the common 2d element between base and arm curve component , spin the element using base node and axis to rotate

• To mesh the arm straight component , use 3d>linear solid option
• We should mesh each end by 2d element and join the same in this method
• Already one end of arm stright component is meshed by hexa element , to extract 2d element from hexa element , go to tools>faces extract faces option
• One end of the component will have 2d elements, mesh the other end with same number of elements to avoid penta elements

• To mesh the boss component we will be using Solid map option
• Mesh the boss one side and solid map the element to the ither end by nodes
• Now after meshing all the components by hexa elements we have to delete all the 2d elements present in the model
• Go to delete option select elements by config option and slect quad 4 element, now all the 2 element will be deleted

CONCLUSION:

• Understood how to calculate speed of sound in different material, frequency, time step
• Understood how to read input radioss file
• Understood how import the radioss solver deck file anf feed the value
• Understood how to export the file in .rad format
• Got to know how to create 3d tetra mesh and hexa mesh
• Learnt how to give diffrent type of 1D connection and hyperbeam concept