Simulate The Bending of An IPHONE and Calculate Fatigue Life Using ANSYS WorkBench

Objective: Simulate the bending of the iPhone as per the given cases below.

Case 1: Simulate the model as it is given in the video

Case 2: Move the bottom fingers from their defined position to the given position X= 22.5mm & Z= 10mm and obtain the results for the simulation. Also, define the S-N curve for the Aluminium Alloy material as per values given below and determine the fatigue life results for the same.

Stress, MPa	Number of Cycles, N
225	10000
175	100000
143	1000000
110	10000000
80	100000000

Theory:

Material expansion occurs on the outside surface of the bend, compression on the inside, and we need to know how to deal with both. The limits of material ductility will be the controlling factor for the minimum bend radius.

The strains associated with the plastic deformation when cold forming can cause the material to strain harden. This can change the material’s mechanical properties in the area of the bend, where plastic deformation is occurring.

At this point, ductility and resistance to fracture will need to be considered. We will verify that which material has high ductility and best suitable for sheet metal bending.

What is Ductility? It is the property that permits a maṭerial to be drawn out longitudinally to a reduced section, under the action of tensile force. Also, strength which enables the material to resist fracture under load. Strength is the most important property from the design point of view

Model Given:

Outer Frame Inner Panel Display

Material used:

Connections:

Contacts:

Joints:

Mesh:

Analysis Settings:

Fixed Support:

Displacement:

Joint displacement:

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Solutions:

Deformation:

Equivalent Stress

Equivalent Strain:

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Case 2:

In this case, we have shifted the thumb location to the middle.

Solution:

Deformation:

Equivalent Stress:

Equivalent Strain:

Fatigue:

Added SN Curve value to the aluminum alloy:

Solutions:

Fatigue life:

Results and conclusion:

	Case 1	Case 2
Deformation (mm)	7.938	7.912
Stress (MPa)	630.3	479.38
Strain (mm/mm)	0.008	0.006

Changing the location of the thumb from the sideway volume & power hole decreases the stress generated in the model and deformation and has almost no effect of the same because

when the thumbs placed in the middle force were equally distributed so the stress generated is low.

This simulation was just for experimental purposes because trying to displace the model 8 mm can damage the internal parts severely due to force produced.