week-11 Joint creation and Demonstration

• OBJECTIVE

The objective for this project is to demonstrate the creation of joints in Ls Dyna. The following joints will be created with deformed and rigid bodies.

• Revolute
• Spherical
• Cylindrical
• Translational

PROCEDURE

Revolute (rigid body)

The shell body 1 & 2 is created using shape mesher (4N shell entity). Body 1 is created using these node cordinates and body 2 is created woth some few apparent distance from the first 4 nodes.

NID	X	Y	Z
1	100	120	350
2	100	120	350
3	100	120	350
4	100	120	350

1. The material used is material 020 Rigid. This is created using the MAT keyword.
2. The section card shell is used with ELFORM=2 AND T1=1.
3. Part keyword is used to specify the (MID) and section(SECID) for each Part.
4. DEFINE keyword is used to define a curve which would later be assigned for displacement of body 1.

0	0
1	10
1.1	10

5. CONTROL Keyword is use to specify TIMESTEP (DTINIT = 0.01 , TSSFAC = 0.9)
6. CONTROL Keyword is used to specify TERMINATION TIME (ENDTIME=1).
7. Using Node edit , 4 nodes (500,501,502,503) created between body 1 & 2.
8. Using CONSTRAINED EXTRA NODES Keyword, the nodes are assigned to body 1(nodeset_500,501) and body 2(nodeset_503,502).
9. Using CONSTRAINED Keyword, the revolute joint is created using JOINT REVOLUTE (N1 =500, N2=503, N3=501, N4=502).
10. Using BOUNDARY Keyword, prescribed motion set is used on body 2 for displacement(DOF=3, VAD=2,LCID=1).
11. Using BOUNDARY keyword SPC_set is used to fix body 1 with all DOF=1

POST PROCESSING

REVOLUTE (DEFORMED BODY)

All keywords stay the same for the joint woth deformed body except for a few which is described below:

• The material used is material 001 Elastic. This is created using the MAT keyword.
• CONSTRAINED NODAL RIGID BODY are created to connect body 1 with nodes (Pnode_1000, Pnode_1002) and body 2 with nodes (Pnode_1001, Pnode_1003).
• 
  
• Using CONSTRAINED keyword, the revolute joint is created using JOINT REVOLUTE( N1=1000, N2=1003,N3=1001,N4-1002)

RESULTS

SPHERICAL (RIGID BODY)

The shell body 1(circle) and 2(semi-circle) is created using shape mesher (Sphere shell).

All keywords stay the same for the joint woth deformed body except for a few which is described below:

Using CONSTRAINED EXTRA_NODES_NODE keyword, the nodes are assigned to body 1 (node1000) and body2 (node1001).

1. Using CONSTRAINED keyword, the revolute joint is created using JOINT SPHERICAL (N1=1000, N2-1001)
2. Using BOUNDARY keyword, prescribed motion set is used on body 2 for displacement (DOF=6, VAD=2,LCID=1)
3. Using BOUNDARY keyword,spc_set is used to fix body2 with all DOF=1

SPHERICAL (DEFORMABLE BODY)

All keywords stay the same for the joint wIth deformed body except for a few which is described below:

• CONSTRAINED NODAL RIGID BODY are created to connect body 1 with nodes (Pnode_1001) and body 2 with nodes (Pnode_1000).
• Using CONSTRAINED keyword, the revolute joint is created using JOINT SPHERICAL (N1=1000, N2-1001)
• MAT 001 ELASTIC is used

RESULTS

TRANSLATIONAL JOINT

The shell body 1 and 2 is created using shape mesher(Box Shell)

All keywords stay the same for the joint wIth deformed body except for a few which is described below:

1. Using CONSTRAINED EXTRA_NODES_NODE keyword, the nodes are assigned to body 1 (nodeSETID_1) and body2 (nodeSETID_2).
2. Using CONSTRAINED keyword, the translational joint is created using JOINT_TRANSLATIONAL (N1=13000, N2=13001,N3=13004,N4=13005,N5=13002, N6=13003)
3. Using BOUNDARY keyword, Spc_set is used to fix body 2 with all DOF =1.

CONCLUSION

This report has demonstrated successfully the creation of three joint types in Ls Dyna between rigid and deformable body. I was having issues submitting the report so I was advised to remove all images which is the reason why there are no images in the report.