ENGINE FILE EDITING AND 3D MESHING USING RADIOSS

                                                                  

 

OBJECTIVE: 1. To check the Material Property for the given Starter File and Calculate the Speed of Sound in that material.

                    2. Calculate the time taken for sound to travel the length of the rail.

                    3. Edit the Engine file according to the given question.

                    4. Calculate time frequency with 20 animation steps.

                    5. To perform a Tetra Meshing on the given component.

                    6. To perform a Hexa Mesh on the component.

PROCEDURE:

1. To check the material of the rail component we need to import the starter file (000.rad) in HYPERMESH.

    While imorting select USER PROFILE as RADIOSS

                                                                      USER PROFILE

To import the starter file 

Go to File >> Import solver deck >> Select starter file >> Import into hyper mesh GUI

                                                      IMPORTING RAIL MODEL

                                                          SELECT STARTER FILE

                                              STARTER FILE IN FORMAT OF 000.rad

          IMPORT STARTER FILE

                                                               IMPORTED STARTER FILE

After importing the file we need to click on materials in the MODAL TAB

  CHECKING MATERIAL PROPERTIES

 

GO to Modal tab >> Material >> Steel 

              MATERIAL PROPERTIES

As above fif we can see the varous properties such as Rho {DENSITY}, E{YOUNGS MODULUS}, NU{POSSIONS RATIO} of steel material in the TAB.

We can also see these properties by opening starter file into NOTEPAD.

                                              OPENED STARTER FILE IN  NOTEPAD

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

In the material properties we can see that

DENSITY = 0.0078 kg/m3

YOUNGS MODULUS(E) = 210000N/m2

calculate the speed of sound in steel rail = `√ E/ρ`

So here it will be √( 210000/0.007)`

Hence the value of Speed of Sound will be 5188.74 ms-1 

 

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.

Since we have already calculated the speed of sound 

So, we can use formula 

SPEED=DISTANCE/TIME

now we want Time 

So, TIME = DISTANCE/SPEED

DISTANCE=1000mm

convert mm into m

So, DIATANCE =1m , SPEED = 5188.74 ms-1

Time= 1/5188.74

Time= 0.0001927 s

Time = 0.1927 ms                           this is the unit for time because the other units were used on the similar scale

 

3.Time for sound to travel length of rail

Same as above

Time for sound to travel length of rail = 0.1927 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)

WE already know the time for the sound wave to travel the distance of rail is = 0.1927 ms

Hence, Our runtime need to the exact value 

So, after importing file, We need to select 

Model tab >> Card >> ENG_RUN >> Tstop= 0.1927 

          ENTERING Tstop VALUE

 

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

Tfreq = RUN TIME/NUMBER OF ANIMATION FILE

Tfreq=0.1927/20

Tfreq= 0.00964

 

               ENTERING Tfreq value

 

6.Change /print -10

Its already in /print -10

After entering the values 

Now RUN the model 

Got to Analysis >> Radioss >> Save as file select >> Run >> Yes

                                                                      TOOL COMMAND

After run we got proper 20 animation file

                                ANIMATION FILES

                                                     Tstop and Tfreq values

 

7.

A: TETRA MESHING OF A GIVEN COMPONENT

AIM : To perform 3D mesh and clear tet collapse for a given component

Procedure for volume tetra mesh:

• Import file to hyper work
• Geometry clean-up
• Toggling of line
• Assign quality criteria
• Volume mesh
• Check for Tet Collapse errors

IMPORT FILE IN HYPER MESH:

Import geometry file into the hyper mesh GUI

To import a model 

Go to File >> Import geometry >> Import 

But be make sure the USER PROFILE is in the RADIOSS

                                                                IMPORTING GEOMETRY

                                                                        MODEL IMPORTED 

GEOMETRY CLEAN-UP :

Once the model is imported move to geometry cleanup just to check weather there any extra surface or free edges or missing surface will present or not

To check a errors 

Goto visualize panel >> Disable shared edges and all except free edges

                                   or

Swtich to wire frame mode

 

                                                     WIRE FRAME MODE

Here we do't see any geometry error 

TOGGLING OF LINE:

Toggling of lines means suppose we are having a two shared lines which is having a distance between those is 2mm but our minimum length quality criteria is 3.5mm at this situation we have to toggle the lines which ever failing for minimum length 

Go to Quick edit >> Toggle >> ok

                                                               QUICK EDIT TAB

 

                                                             TOGGLED LINES

ASSIGN QUALITY CRITERIA :

Assign quality criteria for a given model

Go to preferences >> criteria file setting >> Enter the values >> ok

                                               SELECTING PREFERENCES IN TOOL BAR 

                                                                   QUALITY CRITERIA TAB

MESHING:

FEA stands for the finite element analysis which means that elements are analysed and integrated over a region to derive the final result. so, in a continuous member, which in reality are everything starting from a pin to automotive parts. there are infinite nodes and it’s not possible to solve an infinite equation. so meshing is carried out so that we can desecrating that continuous member into number of finite nodes. and hence go for solving the equations. after that interpolate the results for entire domain. 

Mesh the given components with a given quality criteria 

Here given criteria is 

MAX length: 7

MIN length: 3.5

TARGET length: 5

TET-COLLAPSE: 0.150

Now mesh the component with volume mesh

Go to 3D page >> Tetra >> Volume tetra >> Select surf >> Mesh

                                                                       TETRA TAB

                                                                  VOLUME MESHED 

CHECK FOR TET COLLAPSE:

There is only one quality to check for 3D meshing, that is the Tet Collapse.

To check for Tet Collapse:

Tools >> Check Elems [F10] >> 3D >> Tet Collapse  0.15 >> Save Failed

Check the status bar to view the number of failed elements. 

The status bar is present in the bottom left corner.

As we have already fixed for 2D Element Quality on the surface, we have only 149 Tet Collapse errors.

we can fix this error by manually or by remeshing the tetra elements

                                                      TET-COLLAPSE ERROR 

Now we have to remesh this 3D elements to fix the Tet collapse error's

For that

Go to 3D >> TETRA MESH >> Tetra remesh >> Select the save failed elements with adjust elements >> Remesh

                                                         ZERO TET COLLAPSE ERROR

To see the tetra elements 

Go to Mask (F5)  >> Select element >> Mask 

                                                                         TETRA ELEMENTS

B: HEXA MESHING OF A GIVEN COMPONENT

AIM: To perform hexa meshing for a given component

PROCEDURE:

• Import model into heper mesh
• Geometry clean-up 
• Hexa meshing

IMPORT MODEL INTO HYPER MESH :

Import a model into hyper mesh 

Make sure while importing USER PROFILE should be in RADIOSS

                                                                     USER PROFILE

Now import the geometry

Go to File >> Import given goemetry >> Import the model 

                                                                    IMPORTING GEOMETRY

                                                                         MODEL IMPORTED

GEOMETRY CLEAN-UP:

Once the model is imported move to geometry clean up just to check whether there any extra surface or free edges or missing surface will present or not

In lower body part i can see some free edges 

So here we have to fix this error by manually

Check for other errors also 

To check a errors 

Go to visualize panel >> Disable shared edges and all except free edges

                                               OR

Switch on wire frame mode

                                                       WIRE FRAME MODE

No errors are present in this model

HEXA MESHING:

FEA stands for the finite element analysis which means that elements are analysed and integrated over a region to derive the final result. so, in a continuous member, which in reality are everything starting from a pin to automotive parts. there are infinite nodes and it’s not possible to solve an infinite equation. so meshing is carried out so that we can desecrating that continuous member into number of finite nodes. and hence go for solving the equations. after that interpolate the results for entire domain. 

Mesh the given components with a given quality criteria 

Here given criteria is 

 

TARGET length: 10

Now mesh the component with 2D

Got to >> 2D >> Automesh >> Select base surface >> Element size =10  >> Type: Mixed >> Mesh

                                                                       2D PAGE

                                                                 AUTOMESH TAB

While meshing select mesh type as quad and their should be no rotating quad

                                                               2D MESH

Now we have drag this 2D elements to form a HEXA mesh 

Go to 3D >> Element Offset >> Select the elements >> Select surf >> No. of layer to drag =5 >> Offset.

                                                                           3D page

                                                          ELEMENT OFFSET TAB

                                                               HEXA ELEMENTS

Now do the same for other parts also by using different commands

For 2nd part (ARM CURVE) 

First make arm curve part as current component

Now for draging we have to select the 2D mesh of base part 

Fo that 

Go to Mask >> elements  >> Under elem by con-fig >> Hexa 8 >> Select entities >> mask

                                                                  MASK TAB

                                                      SELECTING 2D ELEMENTS

                                                       MASKING HEXA ELEMENTS

After masked of hexa elemets we left with only 2D elements

Select the 2D elements to spin 

Before spining the elements we have to create a center point 

For that 

Go to Distance >> Select three noded >> Hold line with left click >> Select N1, N2 and N3 in highlited line >> Create

                                                                    DIATANCE TAB

                                                               CENTER NODE CREATED

Now select the 2D elements to convert hexa elements

For that

Go to 3D >> Spin >> Spin elem >> Select element >> Angle as 90 >> On spin = 25 >> Base: X axis >> Spin

Note: For plane of rotation X-axis indicates the global axis for which the plane is normal

                                                                             3D

                                                                          SPIN TAB

                                                            ElEMENTS ARE SPINED

Now for arm straight (comp 3) 

Here also we need 2d elements to drag 

So, for that 

Go to Tool >> Faces >> Comp: arm curve (comp 2) >> Select >> Find faces

                                                                      TOOL PAGE

 

                                                            SELECTING COMP 2

Now hide all the mesh

Make current component as arm straight (Comp 3)

                                              WIRE FRAME MODE

As the above fig show the 2D face 

So, select the elements to drag

Go to 3D >> Linear solid >> For linear solid we want destination elements so for that create 2D for Comp 3 meshed with equal number of nodes >> Go back

                                             2D MESH CREATED ON COMP 3

Go to 3D >> Linear solid >> From elem: select 1st face i.e comp 2 >> To elem: Select 2nd face i.e comp 3 >> Alignment 1: Select N1, N2 and N3 for comp 2 >>  Alignment 2: Select N1, N2 and N3 for comp 3 >> Density =12 >> Solid.

                                                         LINEAR SOLID COMMAND

                                                    SELECTING N1, N2 and N3 NODES

                                                               HEXA MESH CREATED

Once hexa mesh is created 

Goto tool >> Faces >> Delete 

Last component (BOSS)

To created hexa mesh for comp 4 

Go to 2D >> Mesh the side of boss comp surface >> Make sure comp 3 and comp 4 have same No. of nodes 

                                                                 AUTO MESH TAB

Now convert 2D mesh to HEXA mesh

For that

Go to 3D >> Solid map >> Line drag >> Select elements >> Along geom: Node path >> Mesh 

                                                   SELECTING SOLID MAP TAB

                                                                    LINE DRAG 

                                                         DRAGED THE ELEMENTS

Now delete all 2D elements we dont want this

Go to delete >> Element >> Under element QUAD 4 >> Delete

                                                              DELETE TAB

                                                                             HEXA MESH

RESULT :  The Tetra and Hexa mesh is created for the given models as per the given quality criteria using HYPERMESH and having zero Tet collapse error for tetra mesh and edited engine file

                                                                   HEXA MESH

                                                                  TETRA MESH

                                                                    ENGINE FILE EDITED

CONCLUSION:

 I would like to conclude that this assignment helped me gain a  overall look of how to run a simulation in the RADIOSS solver and how to alter the number of Animation files and how to done tetra and hexa meshing.