Assignment 5-RADIOSS Interfaces & Study of Effect of Notches Challenge

Aim-

• Perform 2D mesh on bumper assembly given with 6mm element size.
• Run the crash tube model with different types of interface contacts.

Objective-

• Run the crash tube model as it is given.
• Change the inacti-6 to avoid initial penetration and run the model.
• Create type 11 type contact with the required parameter.
• Removing of notch over the crash tube and boundary conditions on rigid body node and run.
• Create a new notch in the middle and run the model.
• Create a new notch on opposite faces only ad run the model.
• Postprocessing of all cases, review the model in hyper view and graphs in hypergraph 2D.

Procedure-

1. clean the geometry on which we are going to mesh.

Here use the surface intersection to join both surfaces.

• Go to surface edit > trim with surface plane > self-intersecting surface.

• Now perform equivalence on overlapping surfaces.

• Geometry cleanup is done.
• Once cleanup is done go for meshing

• Go to 2D > automesh > select surface > mesh size-6mm

2).

Case 1 Run the simulation as it is given.

Import the starter file in radioss solver deck.

Now run the simulation-

• To run the simulation go to Analysis > Radioss.
• After clicking Radioss click on the input file and save it in a new folder as Case-1.
• Check the include connectors and option as -nt 4.
• N indicated how many cores will involve to run the simulation.

• Now open 0001.out file and check all the details.
• Here we can see all variables in the out file about energy and mass loss also.
• So for checking the maximum loss check the last cycle details.

Post-processing-

a) Review the simulation using Hyperview.

b) Plot the graphs using Hypergraph-2D

Rigid wall force-

• The total resultant is of rigid wall forces is increasing initially means the tube have elements get colloids and gradually increasing from the time interval 20ms
• The colloids between the elements have created the increasing force with the colliding action as shown in below

Internal energy

• The internal energy has been initially does not have any deformation after some time interval the deformation gets in the mesh model and increase gradually. At reaches the max deformation the internal has been getting constant

Kinetic Energy:-

• As shown in the graph with high kinetic energy w.r.t time the graph will decrease as velocity has been decreasing the kinetic energy also gets decreases as shown above.

Contact energy:

• Initially, we can see the contact graph is lower because initially, deformation is less, and contact between tub elements are less.
• As tube getting crushed 80-90% mainly after 20th ms most of the elements are in contact closely so at that point contact energy will boom to a higher value.
• This contact force is actually helping to create spring force which results to avoid penetration between elements.
• The graph is decreasing after some time just because after a complete crush of the tube it rebound back of some portion so contact forces will decrease.

Case-2:

Change the Inacti=6 and run the model.

After creating the self contact for the element assign the Inacti of 6 in Type 7

• Now run the simulation and save the radioss file as a different case as case-2.
• After running the simulation we will get the animation file, h3d file, and also T01 file.

Post-processing-

a) Review the simulation using Hyperview.

b) Plot the graphs using Hypergraph-2D

Rigid wall force-

• Here in this case also elements go into contact with rigid walls same as case-1 so the behavior of the curve will also be the same as 1st case.

Internal and Kinetic Energy:-

• The internal energy has been initially does not have any deformation after some time interval the deformation gets in the mesh model and increase gradually. At reaches the max deformation the internal has been getting constant
• As shown in the graph with high kinetic energy w.r.t time the graph will decrease as velocity has been decreasing the kinetic energy also gets decreases as shown above.

Contact energy-

• In this case, also contact energy will increase in order to elemental contact with respect to time.

Case-3: Create the type 11 contact and run.

• After assigning the self contact and the type 11(Edge to Edge Contact) has been selected.

• Now run the simulation and save the radioss file as different case as case-3.
• After running the simulation we will get the animation file, h3d file, and also T01 file.

• Now open 0001.out file and check all the details.
• Here we can see all variables in the out file about energy and mass loss also.

Post-processing-

a) Review the simulation using Hyperview.

b) Plot the graphs using Hypergraph-2D

Rigid wall force:-

• In the same manner, due to less deformation, the force acting by elements to the rigid wall will be less.

Internal Energy:-

• As initially not have any deformation in the tube so initial energy has been started from origin. After the tube gets deformed with the increasing the graph.

Kinetic Energy

• The tube has initially had high kinetic energy and after some time interval the kinetic energy has been decreases as shown above

contact energy

• In contact energy also due to less deformation no of elements getting into contact is also less.
• So there is little less gain in contact energy.

Case-4: Remove both notches and remove boundary condition on rigid body node then run.

• To remove notches go to Edit node>Align node and select nodes to align.
• For deleting boundary condition go to solver > BCS > Delete boundary condition.

.

• Now run the simulation and save the radioss file as different case as case-3.
• After running the simulation we will get the animation file, h3d file, and also T01 file.

• Now open 0001.out file and check all the details.
• Here we can see all variables in the out file about energy and mass loss also.

Post-processing-

a) Review the simulation using Hyperview.

B) Plot the graphs using Hypergraph-2D

Rigid wall force-

• The resultant rigid wall forces will decrease compared to the previous case because here in this case we had removed boundary conditions.

Internal Energy

• As initially not have any deformation in the tube so initial energy has been started from origin. After the tube gets deformed with the increasing the graph.

Kinetic Energy

• The tube has initially had high kinetic energy and after some time interval, the kinetic energy has been decreasing as shown.

Contact energy-

• Contact energy is also reduced compared to the previous case is because of the removal of notch and boundary conditions.
• Due to the removal of notches deformation is layered and uniform that's why contact between elements is less.

Case-5: Create a new notch in the middle, select the whole section and run.

• Create the notch in the middle by offsetting the elements.

• Now run the simulation and save the radioss file as a different case as case-5.
• After running the simulation we will get the animation file, h3d file, and also T01 file.

• Now open 0001.out file and check all the details.
• Here we can see all variables in the out file about energy and mass loss also.

Post-processing-

a) Review the simulation using Hyperview.

b) Plot the graphs using Hypergraph-2D

Rigid wall force-

• Rigid wall force is also following the same pattern as case-1 and the maximum value will be less than the first case is because of the notch at only one place in this case.
• There will be a drop-in maximum value compared to the previous case(case-4).

Internal energy

• As initially not have any deformation in the tube so initial energy has been started from origin. After the tube gets deformed with the increasing the graph.

Kinetic Energy

• The tube has initially had high kinetic energy and after some time interval, the kinetic energy has been decreasing as shown.

Contact energy-

• Due to a notch increase in contact energy, we can see. Due to notch friction between elements will be more hence contact energy increased compared to the previous case(case-4).

Case-6:Create a new notch with nodes only from opposing 2 faces and run.

• Create notch using the element offset method. Go to 2D > Element offset.

• Now run the simulation and save the radioss file as different case as case-6.
• After running the simulation we will get the animation file, h3d file, and also T01 file.

• Now open 0001.out file and check all the details.
• Here we can see all variables in the out file about energy and mass loss also.

Post-processing-

a) Review the simulation using Hyperview.

b) Plot the graphs using Hypergraph-2D

Rigid wall force-

• Rigid wall force is also following the same pattern as case-1 and the maximum value will be less than the first case is because of the notch at only one place in this case.
• There will be a drop-in maximum value compared to the previous case(case-4).

Internal energy

• As initially not have any deformation in the tube so initial energy has been started from origin. After the tube gets deformed with the increasing the graph.

Kinetic Energy

• The tube has initially had high kinetic energy and after some time interval, the kinetic energy has been decreasing as shown.

Contact energy-

• Due to a notch increase in contact energy, we can see. Due to notch friction between elements will be more hence contact energy increased compared to the previous case(case-4).

CASE	KINETIC ENERGY	ENERGY ERROR	MASS ERROR	CONTACT ENERGY	RIGID WALL FORCE	Internal Energy	Type of Interface used.	NUMBER OF CYCLES	Elapsed time
CASE-1	44401	-3.8	0.000	1703.13	1256.06	42469.9	Type 7	83496	153.46 s
CASE-2	44401	-3.8	0.000	1707.13	1256.06	42469.9	Type 7	83496	151.89 s
CASE-3	44400.8	-8.1	0.000	3921.31	1521.43	40304.7	Type 7 & Type 11	111137	414.35 s
CASE-4	44400.7	-3.0	0.000	1563.75	1209.74	42595.8	Type 7 & Type 11	77771	140.83 s
CASE-5	44400.8	-3.1	0.000	3921.34	1521.43	40304.7	Type 7 & Type 11	80105	139.84 s
CASE-6	44400.7	-3.7	0.000	1209.74	1563.75	42595.8	Type 7 & Type 11	91030	167.63 s

Result-

• The bumper model is meshed successfully with a 6mm size.
• Crash model is run with different parameters.
• All 6 cases are reviewed in hyper view.
• Graphs for all cases in drawn in hypergraph 2D.
• Maximum and minimum value variation is analyzed with all cases.
• Hence results of all cases were compared successfully.