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

Aim:

Create the mesh for bumper assembly,mesh size should be 6mm and simulate the six different case in radioss and compare the results.

Procedure:

Model 1 - Create the mesh for bumper assembly,mesh size should be 6mm.

¬Import the given model in hypermesh.

¬Go File - open - select model

¬model displayed in graphics area.

¬Meshing the model in given parameter.

¬Go to - 2D - automesh - choose mesh as 6mm.

¬Mesh the whole components with good mesh flow .

¬Give proper rigid Rbe2 connection.

¬Go to 1D- connectors - spot

¬Select the nodes and connect the elements where its need.

Conclusion:

¬complete mesh the bumper assembly with 6mm size.

¬RBE2 connection are used to connect the element.

Case 1: Run the crash tube model as it is.

¬Import the crash file in radioss.

¬Go to import - choose rad file - import it.

¬No need to change the properties .

¬Question is run the tube as it is.

¬In create TH part to view the graph of all parts of the components.

¬View the TH part - entity - choose all the components.

¬Next simulate the model.

¬Go to Analysis - select radioss - choose where its save -

¬Check include connectors - option type -nt 4 - simulate parallel.

¬This simulation is completed check the result.

¬open Hyperview and contour plots use the H3D file.

¬choose the contour plot and select contact force.

¬Then check the errors .

¬open output file get from the simulation result.

¬Open the output 0001 file.

Energy Error = -3.8%

Mass Error = 0

¬Energy error upto -15% acceptable.

¬Now plot the graph

¬Open hypergraph 2D.

¬Add the T01 file.

¬In this simulation contact force 93N.

¬Internal Energy start from 0 gradually increase and peak between the 25 to 30 ms.

¬Kinetic Energy start from high and decrease gradually it get 0 between 25 to 30 ms.

¬Contact Energy start 0 ms increase gradually suddenly peak after 20 ms and get down slowly.

Case 2 : Change the Inacti=6 and run.

¬In case 2 import the file change the recommended properties to run the simulation.

¬In this case to change the inacti = 6 its helps to avoid intial penetration.

¬Inport the file.

¬Go to model browser - select group - select self contact

¬Then change the inacti value as 6 as recomended.

¬After change the pararmeter to run simulation

¬Same step follow as per previous case.

¬Plots

¬In this simulation get the contact force 94 N.

¬Internal energy 5 , 6 Pshell start to compress at 0 ms Pshell 1,3 start compress at 9.2 ms .

¬Kinetic energy 1,3 pshell start at 54 and gradually decrease reach 0 at 30 ms. Next 5, 6 pshell start with 34 and at 3.4 ms reach peak 34 and decrease gradually reach almost 0 after 11 ms.

¬Contact force start at 4 ms and peak at 26 milli second and decrease flow constant.

Case 3: Create the type 11 contact and run.

¬In this case add type 11 contact with recomended properties.

¬First import the file in radioss.

¬Go to model browser - group - create the new interface.

¬Then change the properties as given below

¬After give the recomended properties to run the silmulation.

¬same steps to follow to run simulation.

¬plots.

¬From the simulation of contact force 780 N.

¬Internal Energy 5,6 pshell start 0 ms increasing gradually peak at 25 ms make constant flow. Then 1,3 pshell start compresing at 9.4 ms peak at 25 ms and constant flow.

¬Kinetic energy 1,3 pshell start at 54 and gradually decrease reach 0 at 30 ms. Next 5, 6 pshell start with 34 and at 3.7 ms reach peak 37 and decrease gradually reach almost 0 after 11 ms.

¬Contact force start at 4 ms and peak at 25 milli second and decrease flow constant.

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

¬In this case remove the notch and remove bcs and run.

¬First import the radioss file.

¬Remove the notch using align option or translate oiption to remove it.

¬After the remove the notch pics.

¬Next another condition in case is remove the Boundary condition.

¬Go to slover browser - select Bcs - remove or uncheck the dof.

¬Uncheck all DOf now it able to move all linear and rotational direction.

¬Now Start to run and simulate the model as same step follow the previous.

¬Plots;

¬From the simulation of contact force 351 N.

¬Internal Energy 5,6 pshell start 0 ms increasing gradually peak at 25 ms make constant flow. Then 3 pshell start compresing at 9.4 ms peak at 26 ms 1 pshell atart at 9.4 ms and peak at 26 and constant flow.

¬Kinetic energy 1,3 pshell start at 54 and gradually decrease reach 0 at 30 ms. Next 5, 6 pshell start with 34 and at 3.7 ms reach peak 37 and decrease gradually reach almost 0 after 11 ms.

¬Contact force start at 2 ms and peak at 26.2 milli second and decrease flow constant.

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

¬In this case to put notch in middle of crash tube and run simulation.

¬Import the radioss file.

¬Then create notch in middle of tube using the translate optiomn to create it .

¬Then run the simulation same steps to follow and get results.

¬plots:

¬From the simulation of contact force 904 N.

¬Internal Energy 5,6 pshell start 0 ms increasing gradually peak at 25 ms make constant flow. Then 3 pshell start compresing at 9.4 ms peak at 26 ms 1 pshell atart at 9.4 ms and peak at 26 and constant flow.

¬Kinetic energy 1,3 pshell start at 54 and gradually decrease reach 0 at 30 ms. Next 5, 6 pshell start with 34 and at 5.9 ms reach peak 37 and decrease gradually reach almost 0 after 11 ms.

¬Contact force start at 2 ms and peak at 26.2 milli second and decrease flow constant.

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

¬In this case create notch with nodes only oppsdite faces.

¬Initially import radioss file.

¬Create notch in crash tube using the translate option.

¬ Simulate this model and get the result.

¬follow the same procedure.

¬From the simulation of contact force 721 N.

¬Internal Energy 5,6 pshell start 0 ms increasing gradually peak at 25 ms make constant flow. Then 1,3 pshell start compresing at 8.3 ms peak at 25 ms and constant flow.

¬Kinetic energy 1,3 pshell start at 54 and gradually decrease reach 0 at 30 ms. Next 5, 6 pshell start with 34 and at 4 ms reach peak 46 and decrease gradually reach almost 0 after 11 ms.

¬Contact force start at 4 ms and peak at 25 milli second and decrease flow constant.

Result:

case	case Type	Energy Error (%)	Mass Error (%)	Max Contact Force(N)	Max Rigid Wall Force(N)	Max contact energy(Kj)
1	Default	-3.8	0	93	1336	2
2	Change the Inacti=6 and run.	-3.8	0	93	1338	2
3	Create the type 11 contact and run	-1.6	0	795	1573	1.2
4	Remove both notches and remove boundary condition on rigid body node then run	-1.5	0	988	1300	1.2
5	Create a new notch in the middle ,select the whole section and run	-1.5	0	904	1532	0.9
6	Create a new notch with nodes only from opposing 2 faces and run	-1.4	0	721	1300	1.1

Conclusion:

¬The bumper model has been meshed and weld with 6mm of element size

¬Then 6 case simulated and check the result and compared.