week-11 Joint creation and Demonstration

 

 

G-drive link: https://drive.google.com/drive/u/0/folders/1S18pT4BTUAOJ-_CcfmpdcvvKG5dY2Guq

Simulation video link: https://drive.google.com/drive/u/0/folders/16dxW1p2dg8mwujoqqLEpOK45ycAKQg3g

Aim:

to create the various type of joints based on the ls dyna user guide

1.revoulte joints

2.spherical joints

3.cyclinderical joints

4.transational joints

 

Case-setup procedure

• part creation
• sec craetion
• mat creation
• RBE creation
• joint creation
• boundary creation
• control creation
• data base creation

 

 

Introduction of joints

• A pair is a joint of two elements that permits relative motion.when any two links or elements are connected in such a way that thier relative motion is completely or sucessfully constrained they called kinematic pair

type of kinematic pair

• If a pair in motion has surface contact between the two elements it is called lower pair.such as a sliding pair ,turning pair and screw pairs lower pair
• Ex:Nut and bolt,socket joint

 

• if a pair in motion has a line or point contact between rtwo elements it is called higher pair 
• Ex:cam and fllower

 

type based on motion

• Sliding pair is when two elements have sliding motion releative to each other it is known sliding pair
• Ex:piston and cylinder
• Rolling pair is when one elemnts is free to roll over other it forms rolling pair
• Ex:a road roller rolling the ground
• Spherical pair one link is constrained to swivel in  or about fixed point it forms spherical pair
• EX: a ball and socket
• Turning pair(revoulte) when two elemnts are connected such that one elements revolves around the other.it forms a turning pair

 

Turning pair(revoulte)

• part creation
  • 
• sec craetion
  • here we use the shell plate so, the element section is shell with t=1.5
  • 
• mat creation
  • we using the mat rigid proprty for this joints both fix and moving parts
  • 
• Joints creation
  • In revoulte joint the parts node should be conincident such example p1 havinh 1,2 nodes and p2 having 3,4 means the  node number 1,3 and 2,4 should be conincident
  • 
• boundary creation
  • While creating the boundary the fix parts is all DOF is completely locked and moving parts id 1DOF translational based on Golbal co-ordinate sysytem
  • 
  • 
• control creation
  • 
  • Basic control and data base  cards are added..

Simulation video:

 

2.spherical joints

• Above same procedure for all but the constraints only may change 

RBE creation

• 

Joints creation

• in spherical join part1 and part2 should be coincedent
• 
• The node 304 and 305 is part 1&2 conincedent

Simulation video:

3.cyclinderical joints

• Above same procedure for all but the constraints only may change but the joints which allow both rotational and translational

RBE creation

• 

Joints creation

• 

Simulation video:

4.transational joints

• Above same procedure for all but the constraints only may change but the joints which allow translational

RBE creation

•  

Simulation video:

 

Conculsion

• in this assignment we learn the various pair of joints and it motion 
• we learn the how create the cnrbe node and how to assign node for particular joints