Week 5 Bending of iPhone
Objective:- The objective of this challenge is to perform a statis structural analysis and to simulate the bending of iphone as per the given cases below and to obtain the directional deformation for the model, factor of aluminium alloy NL and life of the aluminium alloy for the case.
Case 1: To simulate the model as it is given in the video.
Case 2: To move the bottom fingers from their defined position to the given position X= 22.5 & Z=10mm and obtain the results for the simulation. Also to define the S-N curve for the Aluminium Alloy material as per values given below and to determine the fatigue life results for the same.
Introduction:
Bending of iphone:
It's just that under a particular type of flexing, the phone is prone to bend mainly because a metal insert meant to reinforce instead spins in an axis too close to the critical point. If they were further apart allowing better support to counter the flexing and not spinning, it would make it more resistant.
PROCEDURE:-
1. Open the ANSYS workbench software. Under the analysis system select the static structural and wait for few seconds to pop up the window, which contains Engineering data, Geometry, Model, setup, solution and results.
2. Rename the static structure as iphone bending.
3. Under geometry import the iphone bending model. Edit the model by importing it into spaceclaim, if any abnormality found.
4. Update the model by right click and edit the model for preprocessing.
5. Wait for few seconds and ANSYS mechanical will open as shown below.
6. Under geometry rename its parts as display, frame, Inside, Pushing fingers and fingers and assign the material to the model. Assign structural steel for all fingers, assign glass material to the display, aluminium alloy to the frame, and assign polyethlene to the inside.
- properties of a structural steel:-
- Properties of a glass:
-Properties of a polyethyene:-
-Properties of a Aluminium alloy NL:-
-The fingers above the phone are used to hold the phone as well to act as rigid when the force from the down finger is given. So make all the fingers as rigid expect the thumb fingers.
7. Define the contacts, so delete the contacts which is indicated by question mark, and expect Display to frame remaining all make the contact as frictional less,and a Bonded contact between the display to frame is defined.
8. Insert a fixed joints for the fingers by right clicking on connections and insert joint. Change connection type as body to ground, type as fixed and select the respective faces of fongers for scope. Follow the same procedure for remaining fingers.
9. Analysis settings change no. of steps as 8, solver type as Direct, weak spring as program controlled, large deflection ON, non linear stablization as constant, energy disipation as 0.1, activation for first substep as yes and output controll all as yes.
10. Make the inside part of the iphone as fixed support as shown below. so that when the load is applied the phone cannot fly from its position.
11. Similarly the displacement of frame should be only in Y-axis,so use displacement option and select the faces as shown below and make x=0 and z=0.
Joint Displacement:
- Apply joint load for the pushing fingers as shown below and apply a magnitude of 0,2,4,8,6,4,2,0. And type as displacement.
- Now request for the outputs such as equivalent stress, equivalent elastic strain, directional defprmation, force reaction, factor of aluminium alloy NL, life of the aluminium alloy and contact tool.
- Force Convergence:-
- Directional Deformation (Y-axis)
- Equivalent stress:
- Equivalent Elastic stress:-
Case 2:- Changing the positions of pushing fingers.
Import the model into ansys spaceclaim and by using the move option change the positions of pushing finger by X=22.5mm and Z=10mm for both the pushing fingers.
- Initial position:
- Displacement: 
- Directional Deformation:-
- Equivalent stress:-
- Equivalent Elastic stress:-
Graphs:-
-- Tabular Results:-
-Conclusion:-
From the above table we conclude that the case 1 will have maximum equivalent stress of a frame than that of case 2. As well as the equivalent elastic strain is maximum at case 1 when compared to case 2. The maximum directional deformation of 8mm is encounted in case 1 and the maximum directional deformation of 7.9389mm is encounted in case 2, which is almost nearer to each other. The life of an aluminium alloy is 1e^8 is correct as in our cycle it is the maximum value, which we have mentioned in S-N curve. The safety factor in both cases is below 1, which will consider as failure of material. Further optimization have to done in order to make the material to pass.
Animation Links:-
1.https://drive.google.com/file/d/1f6UjTkhhSQ98ktkyk0BxCeFHop6s86wL/view?usp=sharing
2. https://drive.google.com/file/d/1R4jPatJkcf3d7tSZMumn2o8hVkTUecwg/view?usp=sharing
3. https://drive.google.com/file/d/17b5FAXwWrZbPWoF4twKmAatQen7lQZQr/view?usp=sharing