Bending of an Iphone

Aim : To perform an analysis simulating the bending of an iphone.

Section A : Steps involved for setting up the simulation

1. Model adjustment

The above model was first imported in the ansys structural and was loaded in spaceclaim to be edited. By using the merge faces in the repair section, the faces present in the moded were merged and the total number of faces were reduced. Later on, the move option was used to move the bottom fingers by 22.5 mm in the X direction and 10 mm in the Y direction.

2. Materials

• Aluminium Alloy NL : The material properties for the body frame were added in the engineering data in the form of an SN Curve of which the values and chart are shown in the pictures above.
• Glass : The properties for the glass material were added for us as display screen material.
• Polyethylene : This material was assigned for component acting as inside body of the phone.

3. Connections

• Contacts : A bonded type of connection was applied between the display and the frame whereas the rest of the connections were kept as frictionless.
• Joints : A fixed joint was given to the top fingers and trtanslation joint was given for the thumbs as the bottom.

4. Mesh

• A face sizing of 7 mm was given for the bottom surface of the frame and the faces of the thumbs in contact.
• A general meshing size of 8 mm was given for the rest of the model with smoothing quality set to low.

5. Analysis settings

• The analysis was carried out in 8 steps.
• Two faces opposite to each other (Top and bottom faces of the phone) were assigned as fixed suport.
• The sided faces of the frame were fixed in the X and Z direction and set to free in the Y direction.
• A joint displacement load of upto 8 mm max in the positive Y direction was applied on the two thumbs at the bottom and later the analysis was performed.

Section B : Results of the simulation performed

1. Directional dedformation in the Y direction

The maximum displacement load that was applied was 8mm but as shown in the results a maximum directional deformation of 3.67 mm in the Y direction was recorded after performing the simulation.

2. Factor of Aluminium Alloy NL

After performing the analysis, a maximum factor of safety of 9.3279 and a minimum safetty factor of 0.1936 was recorded. A factor of safet greater than or equal to 1 indicates that the frame can withstand more stresses if applied to it. This indicates that the frame is overengineered.

3. Life of Aluminium Alloy NL

The life of the Aluminium Alloy NL was calculated on the basis of the input data given for the SN curve with a maximum number of cycles of 100000000. It can be observed from the results that the life of the frame that is affected the most was in the middle where the displacement as applied and on the edges of the frame, especially near the sections with cut notches for the buttons.

Section C : Conclusion

The analysis was thus performed for simulating the bending of an iphone and the maximum deformation recorded in the X axis was arround 3.4 mm. The Aluminium Alloy NL used as the frame material provideds a great factor of safety which went upto 9.3 and the life of the frame calculated for 100000000 life cycles showed that the frame was affected mostly on sections with the applied forces and on the edges of the frame.

Note : The relevant workbench file for the simulation is included in the zip file attached.