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

Refer: https://skill-lync.com/student-projects/radioss-engine-file-editing

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.

Solution:

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

Firstly, we gonna import the RAD file in import solver deck. To do so, we follow FILE>IMPORT>SOLVER DECK & specify RADIOSS > followed by path provided.

as mentioned above, the imported file is termed as, 'FIRST_RUN_000.rad'

Now, lets begin with checking the Material property. On GUI under model tree, material is mentioned in which steel is mentioned. MODEL TREE > MATERIAL > STEEL. The material property is visualized.

from above,

• YOUNGS MODULUS (E) = 210000 `N//mm^2`
• RHO DENSITY (`rho`)= 0.0078 `Kg//mm^3`
• POISSION'S RATIO = 0.3

There is alternate method to visualize the Material property which is nothing but the imported rad file can be opened in notepad.

Now, lets calculate the speed of sound in steel rail.

we know that, speed of sound in air is C = 5188.74 m/s

and we calculated length of railtrack as L = 1000mm

• 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.

then, Time taken for shockwave = (Length of rail)/(speed of sound in air)

T = 1000/5188.74

= 0.1927 m/s

=0.0001927 sec.

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)

In order to edit file, we import file as per previous method followed by go to MODEL TREE > CARDS > ENGINE RUN > Tstop >CHANGE TIME

replace Tstop from 60 to 0.1927

above changes can be see in notepad document as well, once the updated file exported.

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

since, we want 20 animation step, we gonna calculate time related to frequency.

animation step (As) = 20

time step (Ts) = 0.1927

(T freq) = animation step (As)/ time step (Ts)

= 0.009635

Then, we shall check animation upon T freq & T stop. We begin with Analysis deck under which select radios.

a window appears where, simulation results can been visualize

similarly, the animation can be seen here,

6.Change /print -10.

Inside card we again select ENG_PRINT and print -10 is assigned.

MESHING -

REFER Link - https://skill-lync.com/student-projects/3d-meshing-tetra-mesh-and-hex-mesh

TITLE: 3D Meshing tetra mesh and hex mesh.

INTRODUCTION: A tetrahedral element is a volume with four faces and is analogous to a triangle in two dimensions. It is also the ratio of the volume of the tetrahedron made by the point with the plane containing nodes 2, 3 and 4. While, A hexahedral mesh can be defined as a geometric cell complex composed of 0-dimensional nodes, 1-dimensional edges, 2- dimensional quadrilaterals.

OBJECTIVE: We have provided with two different geometry consisting of Housing & Bracket. The Geometry consist of housing is suppose to be tetra mesh, while bracket as hexa mesh.

• Housing Geometry - Tetra Meshing

Housing geometry is consist of two different parts, hence each is meshed individually. Following are the procedures for tetra mesh execution.

1. CAD model is imported, cleanup is done followed by mesh execution.
2. Firstly, hub component is taken into consideration and 2D mesh is deployed then followed by tetra mesh.
3. Tetra mesh command is used to generate 3d elements along with elemental size of 5mm
4. Quality parameter such as tet collapse can be check here,
5. now. the cover part meshed using quick tetra mesh in utility option.
6. In such way, The Tetra mesh execution is done.

• ARM BRACKET MESHING - HEXA MESHING

Procedures for hexa meshing are as follows,

1. Once the model is imported , geometric cleanup is done.
2. Base plane is first 2d meshed with an elemental size of 10 mm
3. The generated 2d mesh elements are first converted in 3d along the surface of the base. Here, the element type used is quads.
4. Now the 2d meshed is converted into 3d along the surface of the base component and its generated 3d elements are stored in it. Using element offset, the 2d base elements are selected and are offset along the surface of the base for a total number of 5 layers and total thickness of 25mm.
5. Now, the curve arm is switch on, here we are suppose to spin the base plate's element along the arm at an angle of 90 degree. To do so, we select the spin element option in 3d followed by the element selection and the base point with normal axis. angle is specify as 90 degree with on spin as 25.
6. The arm straight component is also meshed using linear solid. The faces of curved arm is selection along with the straight arm's destination mesh surface and the solid is generated.
7. similarly, the boss or cylinder compont, whose base is firstly meshed, followed by the solid mapping, where the base elements are mapped along the entire components.
8. finally, the entire Arm Bracket is meshed.

RESULT: In this way, both tetra & Hexa mesh id deployed over the component.

CONCLUSION:

• Any base component can be 2d mesh and it can transfer as 3d solid along the entire component.
• Generated elements can be later stored inside its organised components.
• elements can be spin along an anle, they can be also solid map, linear solid.