Week 4 -Wire Bending Challenge

Aim: To evaluate the stress and strain generated on three different wires of the same dimensions and different material (Cu Alloy, Al Alloy, Mg Alloy).

Pre-Processing

We begin the simulation by importing the CAD model to space claim and checking for any imperfections before we proceed to open the mechanical module.

Our first step is to assign the different wire materials while the lever and the wheel are of structural steel.

We setup new contacts in between the wire & the wheel and the wire & the lever. Both these contacts are frictional with coefficient of friction 0.2.

We formulate the simulation using Augmented Lagrange with a constant Normal Stiffness factor at 0.1 which is updated at each iteration.

The interface treatment is add offset with ramped effects.

Meshing

Meshing is done using patch conforming method to assign tetrahedron shapes to the discretized elements.

The area of the wire that is going to experience bending is given a coordinate of 3mm in each case in the X&Z axes.

There is a face sizing between the wire and the lever of 2.2mm and another face sizing given to the wire and the wheel with a sphere of influence of 7mm of 0.8mm.

Analysis Setting.

The simulation is carried out over 8 steps defined by time.

The initial time step is 0.1 Second

Minimum Time Step is 0.01 Second

Maximum Time Step is 0.2 Seconds

The solver type is direct with Large Deflection On and the output controls all flipped to yes.

Results

Cu Alloy

	Maximum	Minimum
Stress (MPa)	343.96	0.0044
Strain	0.0031	7.55*10^(-8)

Al Alloy

	Maximum	Minimum
Stress (MPa)	338.77	0.0029
Strain	0.0048	7.62*10^(-8)

Mg Alloy

	Maximum	Minimum
Stress (MPa)	258.4	0.0018
Strain	0.0057	7.70*10^(-8)

Conclusion

We can see from this data that Cu has the highest stress developed while Mg has the lowest.

For the generated strain the case is opposite with Mg having the highest and Cu having lowest.

Mg would be the most suitable of the 3 materials for the low stress developed.