ENG766 Structural Integrity & Optimisation Assignment Brief | WU

ENG766 Module Outcomes Assessed

• Demonstrate a conceptual knowledge of the material allowable and how they are developed.
• Recognise failure mechanisms in metallic structures and state the suitability of their use in applications.
• Demonstrate a critical evaluation of structural integrity, fatigue failure, and how design can be used to reduce the effect of cyclic loading, using Finite Element Analysis (FEA) to evaluate structural optimisation and fatigue analysis.

ENG766 Assignment Task

Optimisation & Fatigue Analysis of a Square Beam Section

Structural optimisation involves multiple engineering disciplines, including computational mechanics, mathematical programming & computer science. The theory is highly comprehensive and practical in methods & technology; consequently it is one of the significant developments of modern design methods. Structural optimisation is used in many fields, including aviation, aerospace, machinery, civil engineering, water conservancy, bridge, automobile, railway transportation, ships, warships, light industry, textile, energy, and military industry, to name just some. Engineering design problems should be solved appropriately, simultaneously pursuing better cost indicator of structure, the improvement of structure performances and enhancement on safety. Nonetheless, structural optimisation design should meet the needs of industrial production based on the accumulation of design experiences. Structural optimisation design is founded on mathematical theory, methods, and computer programming technology as well as its modelling technique.

Therefore, this assignment requires the optimisation and fatigue analysis of a square beam section using the ANSYS software package. Figure 1 provides a schematic overview of the square bean section with all boundary conditions/constraints. The optimisation requirements are provided in Question B.

Figure 1: Schematic representation of square beam section, with FEA boundary conditions.

NOTE: Software Restrictions, as the FEA modelling will be conducted using the ANSYS student version, there are some limitations. The maximum number of nodes for FEA is 30,000; therefore, please use a triangular mesh to maximise element size. Space Claim allows a maximum of 300 faces for a given model (body); therefore, please ensure you “Check Geometry” to ensure these limits in ANSYS Space Claim.

You are Required to Carry out the Following ANSYS Optimisation & Fatigue Analysis Using ANSYS:

A. Generate a square beam section using an appropriate CAD tool and import into ANSYS static structural and conduct a FEA analysis (Structural Steel – use ANSYS material properties), comparing theoretical and numerical values (Normal Stress & Deformation). (This will be used as your benchmark model.)

B. Using ANSYS Space Claim, you must define your Design Space and reduce material by using the shell fill option. Conduct a geometric comparison study to attain the best optimised designs (min 2 designs), with min member shell size = 2 mm, and the maximum volume removed to be 50%.

C. Validate and compare with the original model, presenting total mass, normal stress & total deformation.

D. Conduct a fatigue analysis (Stress-life) on all respective models, with following conditions and present the fatigue sensitivity minimum and maximum base load variation and Biaxiality Indication results:

• Specify a fatigue strength factor (kf) of 0.8
• Select fully reversed loading to create alternating stress cycles
• Select a stress-life fatigue analysis
• Select Von Mises for the stress component
• Specify design life of 1e06 cycles for safety factor
• Self-select and specify lower and upper variations (%) for fatigue sensitivity
• Include Biaxiality indication for comparison

E. Discuss, summarise and conclude your findings for optimisation and fatigue analyses for all numerical models.

Submission Instructions 

What Should be the Format of the Submission? / Where Should it be Submitted?

Your coursework should be in the form of an IEEE conference proceedings. The template for this paper can be found here

This work must not be a catalogue of the individual commands you have used to set up and solve the problem. You should, however, include a general statement of your FEA solution methodology for solving the problem (e.g., choice of grid, grid distribution, background fluid mechanics, description of results, etc.).

Note: University regulations apply regarding late or non-submission of coursework.

All submissions via Moodle Turnitin Only

All submitted work is expected to observe academic standards in terms of referencing, academic writing, use of language, etc. Failure to adhere to these instructions may result in your work being awarded a lower grade than it would otherwise deserve.

ENG766 Hints and Tips

General Hints & Tips

If you are unclear about any of the elements that make up this assignment or are unsure what you are being asked to do, you should ask your tutor for clarification. Any references should be clearly stated and acknowledged, and plagiarism will not be tolerated. Please refer to the university’s study skills guide on referencing and plagiarism for guidance.

• Title: Think of an informative but catchy title. For example, the phrase, "An investigation of...".
• Abstract: It should include the research question, the rationale for the study, the method and the main findings. Descriptions of the method may include the design, procedures, and the samples that will be used.
• Introduction: The introduction typically begins with a general statement of the problem area, with a focus on a specific research problem, to be followed by the rationale or justification for the proposed study. A literature review should also be included to clarify conceptual issues and the empirical context for your assignment. Use literature review to learn about research design for your assignment – build on the work of previous scholars (use Resource Finder, Science Direct, Google Scholar). This section should end with your aims and objectives.
• Methodology: The guiding principle for writing the Method section is that it should contain sufficient information for the reader to determine whether the methodology is sound. Some even argue that a good methodology should contain sufficient details for another qualified researcher to implement the study.
• Results & Discussion: It is important to structure your results to convince your reader of the impact of your research. You need to communicate a sense of enthusiasm and confidence without exaggerating the merits of your results. That is why you also need to mention any limitations and weaknesses.
• Conclusion: Conclude on your results, perhaps using bullet points to emphasise your findings. Propose further work that can be used for future research activities
• Use of Reference: Referencing in IEEE is a requirement; ensure more than 50% of references are peer reviewed (i.e., Journal Papers).

Specific Hints & Tips

• Computational Domain Generation: How was the computational domain generated? Provide enough detail for replication.
• Work on Mesh Generation: How was the mesh generated, and what mesh techniques were used? is the mesh quality appropriate for numerical modelling? Conduct a mesh dependency study.
• Definition and Setting of Boundary Conditions: What are the boundary conditions, how are they assigned, and are they appropriate?
• Proper Defining: Model, Solver, Material: How is the physical model setup in ANSYS Fluent, in terms of physics, materials & solver, turbulence model dependency study, acoustic model.
• Post Processing of Simulation Results: Presentation of results is important; using ANSYS post-processing and generating results in Excel requires additional time and effort.
• Discussion of Flow Behaviour: Try and be concise when discussing flow behaviours, also structure the results very clearly using subheadings.

Marking and Moderation

1st marking will be by Ikeya Uria, internal verification will be by an appropriate member of the academic team.

The external examiner will have an opportunity to sample the work before the academic board.

The Marking Scheme is included at the back of this assignment brief.

Employability Skills Applied

On successful completion of this module, a student will have had opportunities to demonstrate achievement of the following Employability Skills;

Assignment Feedback

NB All marks are provisional until confirmation by the Awards/Progression Board

Marking Scheme