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

ASSIGNMENT 2: RADIOSS ENGINE FILE EDITING AND 3D MESHING

OBJECTIVE:

• To determine and edit the input values for the given Engine file and observe the stress wave propagation.
• To conduct 3D meshing using tetra mesh and hexa mesh for the given models.

Radioss Engine file editing

Model and its Engine file

CALCULATIONS:

• Check the unit system followed by the starter file.

• Check the values for Young's modulus (E) and Density (`rho`)for the material (Steel) assigned.

• Given, E=210000 and `rho`=0.0078
• Speed of sound, c=`sqrt (E/rho)`

c=`sqrt (210000/0.0078)`= 5188.745mm/ms

• If length of the rail is 1000mm, then the time taken for a shock wave to travel along its length is

t=l/c=1000/5188.745= 0.19272ms

• Time for sound to travel length of rail, t=l/c=1001.25/5188.745

RUN time, t(stop)=0.19296ms

• Frequency of animation output for 20 steps, DT=t(total)/20

T(freq)=0.009648ms

PROCEDURE:

• Open the FIRST_RUN_0001 (Engine file).

• Edit the text and change values for /RUN/FIRST_RUN and /ANIM/DT.
• Change /PRINT/-10 to /PRINT/-20.

• Save the engine file.
• Import the starter file to Radioss under Analysis panel and check the results.

RESULT:

• The animation result is viewed in HyperView window.
• Apply the Contour plot using Von Mises stress variation.
• A single stress wave can be observed moving from one end of the rail to other end under 20 frames.

• /PRINT/-20 input in engine file generates energy error and mass data at an interval cycle of 20.

Tetra Meshing

Housing CAD model for Tetra meshing

PROCEDURE:

• Open the model and view in By Topo mode. Check the surfaces for geometric errors or edge connectivity.
• Set the mesh parameters in the Mesh settings.

• Mesh(Trias) the entire surfaces maintaining the quality criteria and complete the model by 2D meshing.

• In 3D menu, select Tetramesh option to convert the 2D elements to 3D Tetra mesh.

• Delete the 2D elements.

Final Model:

RESULT:

• The given models have been 3D meshed using tetra elements.
• The tet collapse is checked and cleared.

HEXA MESHING

Arm bracket CAD model for Hexa meshing

PROCEDURE:

• Select the base for surface meshing maintaining quad elements.

• Create 3D elements from the shell mesh by Elems offset panel.

• Find the arm curve centre using three nodes option.

• Select and spin the required 2D elements from the base at 90 degrees.

• Create 2D elements for the arm straight component using Faces panel.

• Mesh the opposite surface with matching nodes.

• Create solid elements from one face to other by Linear Solid panel.

• Mesh the boss component by matching the nodes with arm straight mesh.

• Solid map the mesh to opposite face by selecting the the node path.

Final Model:

RESULT:

• The given models have been 3D meshed using hexa elements.