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

AIM: To perform crash and analyze the results on each modification

this is done in two process as given,

1. compare the contact parameters between the type 7 and type 11
2. notch modifications in the model

PROCEDURE:

all these operations are carried out in a case wise ,

• Create the mesh for bumper assembly,mesh size should be 6mm.
• Run the crash tube model as it is.
• Change the Inacti=6 and run.
• Create the type 11 contact and run.
• Remove both notches and remove boundary condition on rigid body node then run.
• Create a new notch in the middle ,select the whole section and run.
• Create a new notch with nodes only from opposing 2 faces and run.

CASE1:Run the crash tube model as it is.

• import the model, as it is in .rad file , use the solver import command
• chck for the irreguralties , like free edgs and elements normals, as normals play an important role in contacts
• Go to ANALYSIS>>RADIOSS>SAVEFILE. by including all the connections
• set the preference as "-nt 4" and run tthe simulation
• if all the buildup is accurate, then simulation will be successful,go to hyperview and compare the results

• run the simulation

• click on results and view in hyperview pannel

• results of the analysis are extracted and compared in hte hyper graph as shown

CASE2: Change the Inacti=6 and run.

• Simillarly as in the above case,import the model
• now, we have to set the contact parameter i.e, Iacti=6 from the model tree
• Go to model browser>>GROUPS>SEAM2(TYPE7CONTACT)>>INACTI=6
• also change the name as, type7 as we are to be comparing both the type7 and anf type11 contacts in future cases

• update the model save the destinatin as case2 and run the radioss, if all the parameters are setin correctly simulation will run sucessfully
• extract the results and compare them

• simillarly also, plot all the contact forces,internal energies,contact energy for this case, these are as shown

CASE3:Create the type 11 contact and run.

• Now, we are changing the contact type to type 11
• VIEW>>BOWSER>>HYPERMESH>>SLOVER
• from the solver card open the INTER card>> dropdown and create a new contact card ad TYPE11
• keep all the parameters i side the type 11 as , type 7 recomamended
• here, type type 11 is a edge toedge contact but, most of the parameters resemble to type which is a node to surface contact

• ANALYSIS>>RADIOSS>>SAVE FILE>> INCLUDE CONNECTIONS>>"-nt 4"
• run the simulation,and extract the results

• graphs are plotted for this ccase , which are as shown

Till nowwe have been comoaring te results between the contact type , now in the following 3 case we compare with the effect of notches

CASE4:Remove both notches and remove boundary condition on rigid body node then run.

• import the model on to the work scape
• now, delete the boundary conditions card
• VIEW>>BROWSER>>HYPERMESH>>SOLVER>> BSC card
• delete the card and now alter the mesh with the given requirement
• we have to change the node location i.e, we have to remove the notches present in the FE

• as you can see all the notches in the meshare removed
• this could be done in 2 wys

1. translate
2. node alignment

• as node alignment is a single function commnad it can't be used, so we can use both these commands to cleaf the notches
• once the notches are cleare then, set the model for simulation
• simillarly extract the results and plot the graphs

• as we could denetly see the hange of deformnation, displacement,and stress concentration in the mesh due to the absence of themesh
• all the neceaasry graphs are ploted against the time step and as shown

CASE5:Create a new notch in the middle ,select the whole section and run.

• IN THIS case we have to locatio of the notch from the initial model
• import the previous model and change the mnode locations'
• thos could be done in the above discussed methodes

• as you see , we have created a notch in the middle of the model
• check of the free edges, normals in the model as we have changes the location of the node
• simillar to the above cases, set in the simulate

• observe the change in the deformation
• it occurs early compared to the previous cases,even the deformation also changes , happen at the notch little a head compared to the above cases

CASE6:reate a new notch with nodes only from opposing 2 faces and run.

• Here in this case , notches are to be present only at the opposite sides
• notches are to be only present on 2 sides of the fe model
• observe where ere the notches present in the mesh

• as you can see the notches are at the side mating area of the mesh
• chack and simulate the model
• results are as shown in the figure

COMPARISON OF RESULTS:

here we ae coparing in two sets as given

1. contact type: case1,2,3
2. notch bases: case 4,5.6

COMPARISION OF CASE 1 WITH RESPECT TO 2,3:

lets compare case1 with case 2,3 because it base simulation with out any changes

graph comparision between, contact ,internal , rigidwall forces

CASE1:

1. here, internal energy peaks at a point of time at, T=28 ms obtainng 42500J and decreases due to contact resistance between the node s and the surfaces
2. also, contact energy will be maxium at the same time 2000J and then decreaes due to repulsions
3. vonmisses=7.35e-1, displacemet= 2.8e+2, contct force= 9.35e+1

CASE2:

1. here we just chsnged Iacti value to 6, which is bacisally a default value as in case 1, it is '0', but the hypermesh reads it as 6
2. here by given iacti=6, similar results will occur as case1
3. internal energy=42500J,contact energy= 2000J, at time poinnt t=28ms
4. even the stress, displacement,and cintact forces will be as as csse 1
5. vonmisses=7.35e-1, displacemet= 2.8e+2, contct force= 9.35e+1 simillar to case1

CASE3:

1. here , we can clearly see the difference, we have chnge the contact tyoe as type 11, with type7 parameters
2. type11 is edge to dge contact, so the repulsion occur a bit earlier to the above cases at T=25 ms
3. contact , irigidwall forces also increase at that time point and the decreses due to resistance
4. internal energy=40000J,contact energy=3800J, at time poinnt t=25ms

2.COMPARISON AMONG CASE4,5,6:

all these three case are of type 7 as similar to to the case1 in terms of contact, the only difference is in the location of the notches on the model mesh

case4:

• in this case we have removed the notches entirely as seen above
• as a result the extracted simulated values are as fallowes

• grapg comparison of, contact energy, internal energy,wallforces of cae4,5,6

case4:

1. all the values occur at same range to case1
2. internal energy=42500J,contact energy= 1750J,wall forces=1100J at time poinnt t=27ms
3. here no contact type is changed, so occurs at time T=27 ms, same as case1 and after that the resistance build in between the nodes and surfaces
4. as, the notches are considerabilly changed location, conact energy values increase hare at maxium it is 1750J

case5:

1. hare notch is at the middle , due to these the contact energy is increased
2. even the behaviour of deformation also changes , it first starts at the middle notch reagion
3. internal energy=42400J,contact energy= 1850J,wall forces=1250J at time poinnt t=27ms
4. here no contact type is changed, so occurs at time T=27 ms, same as case1 and after that the resistance build in between the nodes and surfaces

caase6:

1. here, notches are present only at 2 sides
2. all the values of, contact force, contact energy,wall forces considerablly increases
3. internal energy=42400J,contact energy= 1950J,wall forces=1300J at time poinnt t=27ms
4. here no contact type is changed, so occurs at time T=27 ms, same as case1 and after that the resistance build in between the nodes and surfaces

all the above results are tabulated so as to get a clear stastaical view of the results

• also presence of notches mostly increases the strain rate, i.e, more strain suatains more amout of forces during the simulation

CASE	WALLFORCES(N)	CONTACT ENERGY(J)	INTERNAL ENERGY(J)	VONMISSES	DISPLACEMENT	CONTACT FORCE(N)	simulation time	cycles
1	1300	2000	42500	7.35e-1	2.800e+2	9.38e+1	201	83469
2	1300	2000	42500	7.35e-1	2.800e+2	9.38e+1	201	83469
3	1500	3900	40500	7.825e-1	2.650e+2	5.72e+2	568	111003
4	1100	1750	42200	7.42e-1	2.836e+2	6.074e+1	210	73288
5	1250	1800	42200	7.64e-1	2.789e+2	2.098e+2	265	106508
6	1300	1900	42200	7.22e-1	2.773e+2	8.288e+1	258	95211