ENG2125 Design Skills FEA Written Assignment 2025/26 | UOS

ENG2125 – Design Skills FEA Written Assignment

Key information

Learning Outcomes

Apply the techniques of finite-element analysis using commercial software to the resolution of stress distributions in complex, loaded components.

Task

The task for this assignment is to use finite element simulation to improve the design of a composite panel. It will test your ability to construct a suitable model, analyse the results of the simulation using that model and then improve the structure by changing your design. This process is to be captured by a written report that includes important model parameters, your design and improvement strategy, and results showing a final structure that meets the requirements of the technical brief.

By requesting a report with a fixed word count, you will need to identify and communicate the important aspects of your work clearly and efficiently. You should be talking about the design, structural and simulation parameters, as well as critically analysing the output from simulations.

1. Introduction

The aim of this assignment is to decrease the mass and improve the performance of a structural shelf within a series of design constraints. The task requires many modelling techniques used in the preceding weeks of the finite element analysis course. As with many modelling exercises, there are several ways of creating the geometry and structural conditions. It is also not expected that everyone will find the same solution.
The deliverable for the assignment is a report that captures your approach, sound modelling practice, and important simulation output and analysis. You should not submit Ansys files. It is not possible to provide a good report if you have not done the modelling and simulation well.

2. Geometry

You are tasked with creating a platform assembly that supports a total applied load of 3750 N, which is distributed evenly over three equally sized circular areas (Figures 1 and 2). Loading acts in the vertical direction and must not be redistributed. The length and width of the composite panel are fixed as 500 mm and 200 mm (Figure 2). The platform is made of a composite panel lying in the horizontal plane that is fixed to two metal arms (Figure 1). Each arm has a secure bolted connection to a wall on its vertical edges.

When all the layers of the panel are combined, the total depth of the composite panel should not exceed 20mm. You have flexibility in deciding the cross-section of the arms. When deciding what that cross-section is, you should use engineering principles. However, you must adhere to the constraint that box section members are used, no outer dimension can be more than 20 mm and the wall thickness must not be less than 2mm (Figure 3).

Figure 1. Schematic representation of the platform showing the panel (in red), supporting arms and applied load.

Figure 2. Dimensioned view of the panel (left) showing the three cicular areas where the load is applied, and (right) one of the arms of the platform. Dimensions are in millimetres. The circular areas over which the load is applied (dark red) are of equal radius (40 mm).

Figure 3. The limits in millimetres for the dimensions of the box-section material used in the two arms that support the panel.

3. Technical Requirements

The platform assembly should be modelled in a way that is numerically efficient. Approximations used to model constraints, boundary conditions and any contacts should be considered.

The supporting arms should be as light as possible. This goal may be achieved by altering the arms’ cross-section and their material (Section 4). The box sections do not need to be square.

The panel must make best use of the efficiencies offered by a sandwich construction and therefore make good use of a foam core.
The maximum overall displacement under load must nowhere exceed 5 mm. There is no need to consider the factor of safety of the foam core but other components must be demonstrated not to fail. In this context, this requires a factor of safety greater than or equal to one. To limit the scope of the exercise, the factors of safety only need to be considered in tension for any composite materials.

4. Materials

The metal arms are to be made from structural steel or aluminium alloy (using the ANSYS material parameters).

The panel must be of a sandwich construction with a foam core material of Modipur US 569 B produced by HEXCEL (Table 1). This foam core must be applied in 5mm layers.

You may use a mixture of 0o and 90o plies of either Glass Fibre Reinforced Polymer (GFRP) or Carbon Fibre Reinforced Polymer (CFRP) (Table 2). These plies must be applied in 0.5mm layers and show consideration of good engineering practice.

For the foam core, GFRP and CFRP, the material properties that you will need to enter into ‘Engineering Data’ are given in Tables 1 and 2. Parameters required for manual calculation of the factors of safety for GFRP and CFRP layers are given in Table 3. In the panel, you need only consider failure in tension and may ignore compression and shear stresses. Consequently, only tensile strengths for CFRP and GFRP are provided here.

Table 1. Required material properties for the isotropic material Modipur US 569 B – taken from [http://pdf.directindustry.com/pdf/hexcel-corporation/modipur-us-569-b/37685-676334.html]

Table 2. Required properties for the orthotropic CFRP and GFRP materials – adapted from [http://www.performance-composites.com/carbonfibre/mechanicalproperties_2.asp]

Table 3. Ultimate strengths required for calculating the factors of safety of the panel layers – adapted from [http://www.performance-composites.com/carbonfibre/mechanicalproperties_2.asp]

5. Assignment Details

Your written report must be between 800 to 1300 words and include a word count. The word count does not include equations, figure and table captions and table content. Do not use appendices and include no more than ten figures.

There are many instructions relating to the report. It is suggested that you make sure that you have a suitable working simulation before focussing on those instructions. Those instructions are summarised here (in Section 5).

Your report should begin with a brief introduction that summarises the aim of the work and the important features of your initial model.
The methods that you have used to iterate to an improved design should be presented briefly and concisely. This should include the types of output data considered, how the output was used to make design decisions, what those decisions were, and the mechanical engineering principles used to inform the decisions.

You should demonstrate that your FE results are accurate and verify that the model is sound.

Your results, discussion and conclusion should draw on the technical issues identified in the tutorial exercises and questions that have been covered during the course.

Most of the report should focus on the final design and its structural performance. Results should be presented and your discussion should analyse those results.

The mass and factors of safety of the panel and frames should be tabulated. Contour plots of the displacement of the whole structure, stress in the frame, and 0o and 90o stresses in the most critical plies should be presented and discussed. This discussion should substantiate the factors of safety.

At the end of the report, you should have a conclusion and include some brief comments on the limitations of this work and any recommendations you may have to further improve the model and simulation.

Do not present the report as a guide on how to use Ansys software. Instead, you should include the structural, modelling and simulation information that would allow somebody to recreate the simulation in another finite element analysis software package. Do not include an abstract.

The assignment should be submitted as a single .pdf document via SurreyLearn. It will be subject to a Turnitin check.

6.Assessment Details

• Presentation (30% weighting in the mark scheme) to include:
  oYour report should have a professional appearance. Colour should be used effectively with attention paid to presentation of fonts and font styles.
  oThe flow of information in your report should be clear and sensible. A formal structure is expected.
  oParagraphs should be of a sensible length. They should not normally be one sentence and nor should they be excessively long.
  oEnglish usage should be correct in terms of spelling, tenses, and careful and accurate application of technical terminology. You will need to write efficiently and prioritise important output over unimportant work.
• Acronyms are acceptable but should be defined correctly.
• The passive voice or (possibly) third person should be used throughout.
  oFigures and tables should be correctly captioned, sequenced and cited in the text.
• Captions should be a sensible length, descriptive and add value to the figure/table content.
• Captions should not be used to beat the word count.
• Axes and legends should be readable at 100% size.
• Screen captures should be free of artefacts from the software like window borders and menus.
• Model development and its description (25% weighting in the mark scheme) to include:
  oThe important features of the initial model should be briefly presented or defined.
• This should include features that influence the structural response and any important finite element modelling parameters.
• Use of figures from the briefing document is acceptable, so long as they are appropriately cited.
  oAn introduction that very briefly summarises the aim of the work should be included.
  oThe strategy used to go from your initial model to the final configuration should be presented. Your approach should be considered and sensible. How did you use outputs from simulations to improve the next iteration?
• Every iteration does not need to be described though critical results from successive iterations could, for example, be tabulated.
  oWhere suitable, theories of solid mechanics used in your design choices should be presented.
  oTechniques introduced in the classes to assess the suitability of the model should be stated along with any critical output associated with them.
• Mesh Convergence, qualitative and quantitative inspection of the output can be included and presented here to verify the model is acceptable. This should only be brief but any important outputs should demonstrate that the processes have been carried out.
• Results, Discussion and Conclusions (45% weighting in the mark scheme) to include:
  oPresentation and discussion of the factors of safety and weight.
• These results should be presented in the format demanded in this briefing document. The results should be clear.
• An improvement over your initial model should be clear in the output data you present.
• Any formulae used in calculating outputs should be included in the correct format.
  oPresentation and discussion of the requested stresses for each part.
• The discussion should not re-present results. Value should be added by efficiently putting results into the context of the aims of the assignment.
• How have ply orientations been used and why? Are stresses sensible? Which outputs have been inspected and why? Can comparisons be made with other things that you know about structural mechanics.
• Are there any non-essential outputs that can help to explain your findings?
• How have you used what you know about engineering to improve the lay-up of the panel and geometries of the arms.
  oConclusions should be brief and not introduce new information.
• The main outcomes of the approach and study should be clear.
• Limitations and suggestions should for future work should be provided.

The rubric used for feedback can be found at the end of this document. This gives further details of the criteria against which you will be assessed.

Feedback will be provided through the rubric, written comments and a video covering more general trends for the whole cohort.

Opportunities for formative feedback on the modelling and simulation will be available during the timetabled tutorial sessions in weeks 6 and

Marking Criteria