EGH XXXXXXXXXXSemester 1 FEA Part A – Worksheet Due Date: 15th May, 11.59 pm Weighting: 10% To be completed in pairs or individually: Student Name: . Student Number: . Student Name: . Student Number:...

questions are mentioned in the worksheet files


EGH414 2020 Semester 1 FEA Part A – Worksheet Due Date: 15th May, 11.59 pm Weighting: 10% To be completed in pairs or individually: Student Name: . Student Number: . Student Name: . Student Number: . Submission Your submission should consist of a .PDF file containing your responses and two .APDL files containing your simulations. · Your response file must be labelled as follows: PartA_.PDF. · Your simulation files must be labelled as follows: PartA __Beam_Elements.APDL, and PartA__Solid_Elements.APDL · For example, if your student number is n9111111, your files will be: · PartA_n9111111.PDF. · PartA _n9111111_Beam_Elements.APDL. · PartA _n9111111_Solid_Elements.APDL. · The simulation files should be a text file with an .APDL extension instead of .txt. Problem Statement A beam with a channel cross-section is fixed at point A and a load is applied at point C, as described in Figure 1. Figure 1: Cantilever beam with channel cross-section and dimensions The dimensions of the beam are: , , , The load is applied on the surface of the free end, meaning that it acts at the centroid of the channel section. The load has a magnitude of and is applied in the z-direction of the co-ordinate system used in Figure 1. Tasks a) Solve the system analytically: i.e. · Produce a Free Body Diagram, a Shear Force Diagram and a Bending Moment Diagram for the beam. · Determine the stresses at Point A and Point B on the Beam. (2 marks) b) Build 2 models of a cantilever beam in APDL, one using beam elements, the other using solid elements. Upload your .APDL files along with this document, labelled as described in the Submission section. (3 marks) c) Answer the following questions in the boxes given. Expand the boxes if required: What elements did you choose for each model and why? (0.5 mark) What meshing rationale did you choose for each model and why? (0.5 mark) Use APDL to produce all relevant AFD, SFD, BMD and TDs (if appropriate) for the Beam element model. Do they match your analytically determined AFD, SFD and BMDs, etc and if not why? (1 mark) What are the constraints you used at the fixed support and loaded end of the solid element model? Why did you choose them, and did they cause any problems? (1 mark) Undertake a convergence study for both models at both points A and B, using von mises equivalent stress as your convergence criteria. At what mesh density did the models converge at these points (if they do), and why did this occur? (2 mark) EGH414 2020 Semester 1 FEA Part B – Simple Crank Problem Due Date: 29th May, 11.59 pm Weighting: 20% To be completed in pairs or individually Problem Statement This submission requires you to develop, verify and validate a FEA model against both analytical and experimental data. This task will require you to demonstrate that an FEA model in ANSYS APDL is a valid representation of the real system and analyse that components are “fit-for-purpose”. This task requires you to analyse a simplified version of a bicycle crank which is stylised in Figure 1. The crank has been manufactured from 6000 series aluminium alloy with the following properties: = 70 GPa, = 0.3, ultimate tensile strength of 280 MPa, and a yield stress of 140 MPa. The dimensions for the crank are outlined in Figure 2, The bolt is 12.48 mm in diameter and made from steel with the properties: = 200 GPa, = 0.33. Figure 1: Schematic of Crank and Strain Gauge Layout Figure 2: Dimensions of Crank Assignment Tasks: For this assignment, you must: 1. Experimental: You will need to carefully watch the demonstration of the experiment using the apparatus which would normally be undertaken in your workshop. The results of this experiment are given in the Experimental section. This will give you information for your validation step. a. The strain rosette results need to be converted into an appropriate form for comparison with analytical and FEA model results. 2. Analytical: Produce an analytical solution for the model. This includes: a. Develop appropriate load diagrams b. Determine the stresses/strains at points coincident with the strain rosettes in the experimental apparatus. 3. FEA Model: Develop a model of the bike crank in ANSYS APDL. You must: a. Submit a working APDL simulation file with appropriate boundary conditions, element choice and mesh. b. Justify your boundary conditions, element choice and meshing approach in your report. 4. Model Verification/Validation: Compare your APDL model to your calculated and experimental models by: a. Perform a convergence study, or studies on your model. These must be performed at appropriate points on the model and use appropriate convergence metrics/criteria. Discuss (comment on and justify any differences between the results of the models). b. Compare your FEA Model to analytical and experimental data using appropriate metrics. c. Discuss the Verification and Validation of your model i. Does the model behave how we expect it to? ii. Is your FEA Model an appropriate representation of the real system? iii. Are there any areas of your model which do not represent the behaviour of the real system? Identify them and comment on their effect on the usefulness of your model. 5. Fit-for-Purpose: What is the current safety factor of the crank? a. The crank should be designed with a safety factor of 4 under a load of 50 kg.  What changes would you make to the design of the crank to achieve this? b. Confirm that your updated design satisfies a safety factor of 4 using your FEA model and appropriately show the results. Submission Your submission should take the form of a report. · You should include all the basic elements of a report. · A page limit is set at 15 pages (this is more than sufficient to complete the assignment). · Ensure you appropriately explain the problem/focus of the report. Ensure you justify and explain all modelling decisions. Ensure your report is well written and concise. Your submission should consist of a .PDF file of your report and a .APDL file containing your simulation. · Your report file must be labelled as follows: PartB_.PDF. For example, if your student number is n9111111, label your file PartB_n9111111.PDF. · Your simulation file must be labelled as follows: PartB_.APDL. For example, if your student number is n9111111, label your file PartB_n9111111.APDL. · You may draw your geometry in Solidworks (or other software). If you do so, you must attach your geometry file with the naming convention PartB_.. Your simulation file should have the relevant commands to import the geometry file. In your PDF submission: · Include response to the assignment tasks. · Ensure the tasks are complete in order and each task is clearly identified. · Ensure any mathematical working is sufficiently explained (equations and working can be included as an appendix). · Ensure all diagrams are labels and referred to in text. · Ensure all screenshots are labelled and referred to in text. · All parts of the submission must be neat and legible. · Ensure your name and student number is clearly identified on your submission. Group submissions: · If you are submitting as a group, only one member should submit the assignment. · In you file labelling, use the student number of the group member who will submit the assignment. · Ensure the names and student numbers are clearly identified on your submission. If you are unable to submit correctly, email a copy of your assignment (all files) to [email protected] before the due date. Experimental Procedure: 1. Remove the weight from the crank and place on the shelf of the trolley (do not remove the wire from the bolt). 2. Clamp the crank at an appropriate orientation to represent the critical case. 3. Carefully record the orientation of the gauges on each rosette and their values in the unloaded condition. Transience due to noise in the instrument of around 5 - 10 is acceptable. 4. Carefully hang the weight from the bolt ensuring that the hanging wire is snug against the bolt head (i.e. 60mm from the crank). 5. Once the load has reached stability, record the values off the software for each channel of the strain gauge. These values are set to strain (mm/mm). 6. Remove the weight from the crank and place on the shelf of the trolley. Note: if the software throws and error, accept and restart the program. A black arrow in the top right hand corner means that the program in running. Figure 3: a) Experimental Apparatusb) Strain gauge channel orientation Results: Orientation (°) Loaded (m/m) Unloaded(m/m) Rosette A White -45 0.0059144 0.0057497 Rosette A Green 0 0.0064848 0.0063463 Rosette A Red 45 0.0043672 0.0044274 Rosette B Red -45 0.003591 0.0034748 Rosette B Green 0 0.0014786 0.0014531 Rosette B White 45 0.0040375 0.0041577 EGH414 Semester 1, 2019FEA Assignment Part B (20%) Student Name: ____________________________Student Name: ____________________________ Standard Mark: Student Number: __________________________Student Number: __________________________Marker Signature: __________________ Criteria sheet Criteria 7 6 5 4 3 2/1 With respect to this assignment: · It is crucial to understand that this assignment is to test your knowledge of finite element analysis and the use of stress analysis principles in an analytical process. · Any instances of academic misconduct the QUT MOP C/5.3 will be strictly applied. · Demonstrate knowledge and understanding of stress analysis using FEA as a tool and reporting the outcome of the modelling exercise Analytical Solutions (3 marks) Solutions are conducted correctly with no errors (3 marks) Solutions are conducted correctly with a minor error (2.5 marks) Solutions are mostly conducted correctly with several minor errors (2 marks) - Solutions are conducted with significant errors (1