Static Structural Analysis on the iPhone

Static Structural Analysis on the iPhone :

Aim :

• To perform static structural analysis on the iPhone using Aluminium Alloy Material.

Objective :

• To define appropriate material for the iPhone.
• To define contacts for the iPhone model.
• To perform mesh on the iPhone model.
• To Move the bottom fingers from their defined position to the given position X= 22.5mm & Z= 10mm and obtain the results for the simulation.
• To define appropriate Boundary Conditions to the Model.
• To solve and compare the results of the three cases for Total Deformation, Von-Mises Stress, and Equivalent Elastic Strain.

Figure 1-iPhone Bending.

Procedure :

Phase 1- Material Set-Up :

• To set up the material for the Sphere and Plate Model. First, drag and drop the static structural analysis workspace into the project schematic from the analysis system. This is shown in below Figure 2.

Figure 2-Ansys Workbench Workspace.

• After deploying the static structural analysis system in the project schematic workspace.
• Define the Engineering Data and geometry, To define the Geometry and Engineering Data, Right Click on the Engineering Data and click to edit, it will take to the Engineering Tab.
• There Right Click on the Material Tab, A window will Pop-Up stating Engineering data sources.
• Click on the Engineering Data Sources, There go and select the material to define the engineering data. This is shown in below Figures 3,4.

Figure 3-Right Click on the Engineering Data.

Figure 4-Right Click on the Material Tab.

Figure 5-Add these Materials to Engineering Data.

• To add >> General Materials >> Structural Steel ,Polyethylene>> Click on + Button to Add.
• To add >> General Non Linear Materials >> Aluminium Alloy Non Linear >> Click on + Button to Add.
• Create manual material glass, which is shown in the video.

Phase 2-Geometry Set-Up :

• Next set up the geometry. To set up the geometry, Right-Click on the Geometry option >> Import Geometry. This is shown in below Figure 6.

Figure 6-Importing Geometry.

Figure 7-Selecting the Geometry to Import.

• Next double click on the geometry to check, Whether the model imported, is Sphere and Plate Model or not. Space Claim Workspace will open. The model will be imported in the space claim, Which is shown in below Figure 8.

Figure 8-iPhone Model in the Space Claim.

• Now merge the faces in the fingers, Cause if there are more faces in the model, the ANSYS student edition won't accept, Because there is a limit for the Ansys student edition.
• To Merge Faces >> Repair >> Merge Faces >> Select the Faces to Merge.This is shown in below Figure 9.

Figure 9-Select the Faces to Merge.

Figure 10-UnMerged Faces.

Figure 11-Merged Faces.

Phase 3-Model Set-Up :

• Next, define the model, Double click on the model, The Mechanical Workspace will open, There go and define the material, set up the load case for the model.
• The Model loaded in the mechanical workspace is shown in below Figure 12.

Figure 12-Model Loaded in Mechanical Workspace.

3:1 Assign Material :

• Next, define the material as Structural Steel for the Pushing Finger alone which is shown in below Figure 9.
• Similarly, define the Glass material for the Display, Aluminium Alloy for Frame and Polyethylene for the inside. The material properties are shown in below Figures 14,15,16 and 17.
• To assign a material,Click on the Geometry >> Select the Display Geometry >> Parameter Window >> Assignment >> Glass.
• Similarly, assign for the other geometries also.

Figure 13-Assign Material to the Display.

Figure 14-Mechanical Properties of Structural Steel.

Figure 15-Mechanical Properties of Aluminium Alloy.

Figure 16-Mechanical Properties of Polyethylene.

Figure 17-Mechanical Properties of Glass.

3:2 Define Connections :

• For this iPhone bending Model, We have to create two types of contacts. Frictionless and Bonded type.
• Frictionless Type of Contact -Display to Fingers, Display to Inner, Frame to Inner.
• Bonded Type of Contact-Display to Frame.
• keep other contacts as it is the default.

Figure 18-Delete these Two Contacts.

Figure 19-Rename all the Contacts based on Definition.

1) Contact between Display and Finger :

Figure 20-Contact between Display and Finger.

2) Contact between Display and Frame :

Figure 21-Contact between Display and Frame.

3) Contact between Display and Inside :

Figure 22-Contact between Display and Inside.

4) Contact between Frame and Inside :

Figure 23-Contact between Frame and Inside.

• Leave as it is the default for the other contacts.

3:3 Define Joints :

1) Fixed Joint :

• Here all the fingers should be fixed except pushing fingers (Bottom Fingers).
• Connection Type- Ground to Body.
• Joint Type-Fixed.

Figure 24-Defined Fixed Joint.

2) Translational Joint :

• Here for this joint, We have to create a translational joint for the pushing fingers.
• Connection Type-Ground to Body.
• Joint Type-Translational.
• While defining the joint, Make sure to check the coordinate system.
• The translational joint is defined, Which is shown in below Figure 25.

Figure 25-Defined Translational Joint.

3:4 Meshing :

• After defining the connections, We have to define mesh for the Rolling Operation Model.
• There will be a default mesh created for the Rolling Operation model.
• But we have to insert body sizing and face sizing to refine the mesh of WorkPiece.
• To Insert Face Sizing >> Right Click on Mesh >> Insert >> Sizing >> Select Bottom Face of the Frame.Which is shown in below Figure 26.

Figure 26-Insert Face Sizing to Refine the Mesh of Wire and Lever.

1) Face Sizing :

• Select the bottom face of the frame and give the element size as 4 mm, Which is shown in below Figure 27.
• The final meshed model is shown in below Figure 28.

Figure 27-Face Sizing.

Figure 28-Final Meshed Model.

• No of Nodes =23269.
• No of Elements =10956.
• The Fingers have been done by surface meshing with Tetrahedral Elements.
• iPhone model has meshed with tetrahedral elements.

3:5 Analysis Settings :

• Here for this iPhone Bending Model, We are giving 8 steps to run the simulation.
• Solver Type is Direct.
• Auto Time Stepping-Program Controlled.
• Weak Springs-Program Controlled.
• Large Deflection-ON
• Method-Energy.
• Energy Dissipation Ratio is 0.1.
• Activation for First Substep-Yes
• Stabilization-Constant
• Stabilization Force Limit is 0.2.
• Control output settings-Yes for all.

Figure 29-Analysis Settings.

3:5 Boundary Conditions :

1) Fixed Support :

• After giving some parameters in the analysis settings, We have to give boundary conditions.
• Here we have to create four boundary conditions, one Fixed Support, Displacement, and two joint displacements.
• To give Fixed Support, Right Click on the Static Structural >> Insert >>Fixed Support. This is shown in below Figure 30.

Figure 30-Give Fixed Support.

• Here we are giving fixed support to the iPhone model, Select the faces of the inside components.
• The faces selected is shown in below Figure 31.

Figure 31-Defined Fixed Support.

2) Displacement for Frame :

• While performing simulation, The iPhone should only move in the Y direction, So we have to constrain the other directions. Which is shown in below Figure 32.

Figure 32-Defined Displacement.

3) Displacement Joint for the Pushing Fingers :

• Select both the bottom fingers and give displacement joint.
• To bend the iPhone model, The pushing fingers should move in the X-direction from 0-8 mm and return to their original position.
• In the first four steps, the finger will move from 0-8 mm, and in the other four steps, the finger will move from 0-8 mm.
• The displacement joint defined is shown in below Figure 33.

Figure 33-Defined two Displacement Joints.

Phase 4-Request for the Outputs :

• Here we have to request outputs for the VonMisses Stress, Strain, and for Total Deformation.
• To request Output for Stress,Right Click on the Solution >> Insert >> Stress >> Equivalent Von Misses Stress.
• To request Output for Strain,Right Click on the Solution >> Insert >> Strain >> Equivalent Von Misses Strain.
• To request Output for Total Deformation,Right Click on the Solution >> Insert >> Deformation >> Total Deformation.
• This is shown in below Figure 34.

Figure 34-Requesting Outputs for the Stress, Strain, and Deformation.

• Next request output for the contact.
• To request Contact Tool >> Right Click on the Solution >> Insert >> Contact Tool >> Pressure >> Status,Which is shown in below Figures 35 and 36.

Figure 35-Requesting Output for Contact.

Figure 36-Requesting Outputs for Contact Tool.

• Similarly request the output for the Force Reaction.
• The Output requested for the Wire Bending Model is shown in below Figure 37.
• After requesting all the outputs, Run the Simulation.

Figure 37-Required Outputs Requested.

• To run the simulation, Right Click on the Solution >> Solve. This is shown in below Figure 38.

Figure 38-Solve all the Outputs Requested.

• After solving the outputs requested, the simulation results for all three cases are shown below Figures.

Case-2 Move the bottom fingers from their defined position to the given position X= 22.5mm & Z= 10mm :

• In case 2, Move the bottom fingers to the given position.
• To move, Go to Edit in Spaceclaim >> Move >> Move Component >> Select Two Fingers and Move to the desired position. Which is shown in below Finger 39 and 40.

Figure 39-Moving the Finger in the X direction to 22.5 mm.

Figure 40-Moving the Finger in the Z direction to 10 mm.

Figure 41-Moved to Desired Position.

• We have to also define the S-N curve for the Aluminium Alloy, Which is shown in below Figure 42.

Figure 42-Defined S-N Curve.

Case1 [Directional Deformation] :

Figure 43-Directional Deformation.

Figure 44-Directional Deformation Simulation Animation.

Case 2 [Directional Deformation] :

Figure 45-Case 2-Directional Deformation.

Figure 46-Case 2-Directional Deformation Simulation Animation.

Case 1 Equivalent Von Misses Stress :

Figure 47-Case 1 Equivalent VonMisses Stress.

Figure 48-Case 1 Equivalent VonMisses Stress Simulation Animation.

Case 2 Equivalent Von Misses Stress :

Figure 49-Case 2 Equivalent VonMisses Stress Simulation Animation.

Figure 50-Case 2 Equivalent VonMisses Stress.

Case 1 Equivalent Elastic Strain :

Figure 51-Case 1 Equivalent Elastic Strain.

Figure 52-Case 1 Equivalent Elastic Strain Simulation Animation.

Case 2 Equivalent Elastic Strain :

Figure 53-Case 2 Equivalent Elastic Strain.

Figure 54-Case 2 Equivalent Elastic Strain Simulation Animation.

Case 1 Total Deformation :

Figure 55-Case 1 Total Deformation.

Figure 56-Case 1 Total Deformation Simulation Animation.

Case 2 Total Deformation :

Figure 57-Case 2 Total Deformation.

Figure 58-Case 2 Total Deformation Simulation Animation.

Case 1 Saftey Factor :

Figure 59-Case 1 Saftey Factor.

Figure 60-Case 1 Saftey Factor Simulation Animation.

Case 2 Saftey Factor :

Figure 61-Case 2 Saftey Factor.

Figure 62-Case 2 Saftey Factor Simulation Animation.

Results :

Cases	Equivalent Von-Misses Stress of Plate (MPa)		Directional Deformation (mm)		Equivalent Elastic Strain (mm/mm)		Total Deformation (mm/mm)		Safety Factor
	Max.	Min.	Max.	Min.	Max.	Min.	Max.	Min.	Max.	Min.
Case-1	819.17 MPa	6.9531 MPa	5.3661 mm	-1.887 mm	0.012787	2.1263e-004 mm/mm	5.3799 mm	0. mm	15	0.34181
Case-2	587.29 MPa	4.0769 MPa	5.1052 mm	-0.62886 mm	0.0086516 mm/mm	1.9482e-004 mm/mm	5.1057 mm	0	15	0.47676

Table-1

• Here the maximum directional deformation that occurred in case 1 is 5.3661 mm and the maximum directional deformation that occurred in the case 2 is 5.1052, It is somewhat less when compared to case 1. Cause the load applied through the pushing fingers is in the middle of the frame.
• The safety factor for case 1 is 0.34181 and for case 2 is 0.47676, The safety factor is less than one, So both the cases can't sustain the applied loads and they leads to failure.
• So I'm concluding that Both the cases can't sustain the applied loads and they will fail, Cause the Safety factor is less than 1.

Learning Outcome and Conclusion :

In this Week 5 Bending of iPhone Challenge, I came to know about

• Learned how to give Fixed Support to the model.
• Learned to define displacement to the model.
• Learned how to define S-N Curve to the material.
• Learned how to assign materials to the model.
• Learned how to apply boundary conditions to the model.
• Learned how to request outputs and solve them.
• Learned about the Force Convergence.