This includes the analysis of Ball and socket joint

1. Non-Linear/Dynamic Analysis
of Ball And Socket Joint
By:
Sumit Bhattacharya 710
Abhishek Bhoite 711
Sharvil Dalvi 713
Department Of Mechanical Engineering

2. Dynamic Analysis:
Linear static analysis can be performed if:
• Material is linear elastic
• Deformations are small
• Load and restraints are constantly applied
A linear static solution is not valid if above points are violated
The relationship in such cases, between the loads and response become
non-linear and thus Dynamic Analysis must be performed to get
accurate results.

3. Types Of Non-Linear Analysis:
• Material Non-linearity (plasticity, Creep, Viscoelastic)
• Geometric Non-linearity (Large deformations, strains)
• Contact Non-Linearity
There can be combination of both as well

4. Characteristics and General Recommendation:
• The analyst should have insight into behavior of structure
• Sub-structuring should be considered
• The size should be determined based on purpose of analysis
• Prior contemplation of geometric modelling will increase efficiency
• Discretization should be based on stress gradient
• Element types and mesh size should be carefully chosen

5. • Material Non-Linearity: Characterized by material properties,
although the effects may or may not be significant. The anticipated
stress level would be a key to this issue.
• Geometric Non-Linearity: Characterized by large rotations which
cause large displacements. The geometric non-linear effects are related
to the dimensions of structure and boundary conditions. The key is to
know where loading point in the load-deflection curve of critical area is.
• Contact Non-Linearity: Contact can also be classified as a geometric
nonlinearity because the area of contact is a function of the deformation
(some authors puts contact in another class called nonlinear boundary
conditions).

6. Benefits of Non-Linear Analysis:
• Reduce design risk by using simulation to save time and cost
• Accelerate innovation
• Improve reliability of final design
• Obtain more accurate solution

7. Ball and socket joint
• The mechanical joint allows some relative angular motion between
parts in nearly all directions.
• The joint consists essentially of a spherical knob at the end of a shaft,
with the knob fitting securely into a mating socket.
• Applications-
1. Suspension and steering mechanisms
2. Mechanical wipers

8. Ball And Socket Joint

9. Mass Property Calculation:

11. Contact Non-Linear Analysis of a socket made of Nylon
The ball and socket joint similar to those used in windshield wiping
system is analyzed using NX-NASTRAN. The joint consists of a steel
ball pressed into nylon socket that has been insert-molded onto a steel
connecting rod.
Problem Definition: To check the axial force required to pull the ball
out of socket against axial displacement

12. Procedure
• Three D Model
• Idealization of the body
• Perform 2D meshing
• Apply contact and boundary conditions
• Solve using Advanced Nonlinear solution sequence
• Interpret post processing process
• Plot graph

13. Three Dimension Model:
This is a three Dimensional model
Of Ball and socket Joint
made in any CAD software and
The model is idealized.
For proper analysis is spilt the body.

14. Meshing
• Element: 2D
• Collector type: Solid Axisymmetric
• Solid Props: Nylon for socket and steel for ball
• Mesh type: 2D
• Mesh Element : CQUADX 8
• Meshing method: paver
• Element Size: 0.5mm

15. Boundary Conditions
• Fixed Constraint
• User Defined Constraint
• Enforced Displacement constraint:
Where we specify the values of time
and length and specify the node where
it is subjected.
• Axisymmetric Non-Linear Contact

16. Post Processing
The Nodal Displacement is shown
in the Z Direction.
• The Maximum Value is
0.023mm
• The Minimum Value is -2 mm

17. Axial Force VS Axial displacement

18. Conclusions:
Analyzed the socket made of nylon subjected to pressure on its body.
We see the concept of time defining the increase of displacement during
analysis.
Some observations:
• Data of iteration 1 is at right end of curve and iteration 30 is at left end
of curve
• The ball separates from the socket between 0mm and about -2.00mm.
• From -2.00mm to -4.00mm, the reaction force balances the spring
back force produced by socket.