Simulating Bending of iPhone
OBJECTIVE
To simulate the bending of an iPhone in different cases by using Ansys Workbench
Importing the CAD model
The CAD model of the Iphone is imported using spaceclaim and checked for any geometry errors.
Simulation setup
Material Assignment
The display is assigned with Glass material.
The frame is assigned with Aluminium alloy NL material.
All the internals of the phone are assumed as a single soild block which is assigned with material polyethylene.
The fingers are defined as RIGID in their structural behaviour.
Contact definition
The display and frame are given a bonded contact between them.
The top eight fingers and the display are defined with a frictionless contact.
Similarly the bottom two pushing fingers are also defined with frictionless contact with frame of the phone.
The contacts between frame and internal block as well as frame and internal block are defined as frictionless contacts.
The contact inbetween the fingers are not defined as in this simulation it is not required.
Joint creation
The top eight stationary fingers are defined as abody-ground fixed joint.
The bottom two fingers are defined as body-ground translational joint
Mesh Generation
The frame's lower surface and bottom pushing fingers contact surface are meshed with an element size of 4mm and other parts are meshed with default mesh size.
The final meshed part is displayed as below.
Analysis settings
The movement of the fingers are given in 8steps.
The analysing settings are given below
The two opposite surfaces of the internal blocks are fixed and displacement of frame in x-axis and z-axis are defined as zero.
The two pushing fingers are given displacement upto 8mm against the frame and then retracted.
Results
Equivalent stress (whole phone)
Directional deformation (Y-axis)
Factor of safety
Case (2)
In case (2) the two pushing fingers are moved such that they are in middle of the phone and manually a S-N curve is defined for the Aluminium alloy
S-N curve
Two pushing fingers are moved to phone centre by moving 22.5mm in x axis and 10 mm in Y axis.
Then same simulation is done and results are observed.
Equivalent stress (whole phone)
Directional deformation
Factor of safety
Comparison of results
1) The directional deformation is almost same in both the cases
2) The stress is maximum in the case (1) with 640.52 Mpa
3) In case 1 the force required to bend the iphone is much less than case 2 because, in case 2 the force is applied near to the CG of th phone
Ansys file link
https://drive.google.com/file/d/1YHLDkK1stBZUGpINMaKir45h-EW8bdhs/view?usp=sharing