EGB316 Assessment 2: Welded Connection Design Audit (40%)

EGB316 Assessment 2: Welded Connection Design Audit (40%)

Report Due to TurnItIn Monday 1st June at 11:59PM

1. Outline

Students are required to carry out a design audit on a weld group of their choosing that is subject to fatigue loading. The welded joint should be connecting steel or aluminium components (aluminium requires different SN treatment), and analysis should be possible using the techniques developed in EGB316 classes. Also, you must be able to measure all weld group and key system dimensions and approximate/calculate/determine the working loads (application location, direction, magnitude, etc.).

You can choose a welded connection from a machine you are familiar with or some other machine you have access to. The system CANNOT be akin to any of the systems analysed in the lectures (i.e. not a patient lifter or like any design workshops etc.). The main requisite is to investigate a real machine and make design decisions

/engineering judgements regarding properties, forces etc. and determine if the welds are safe. This designation could be done by leaving weld size or material unknown and evaluating one or other using the analysis procedure developed in class, or you could measure/determine/estimate/research all necessary values and establish a factor of safety from the analysis procedure. Either approach will allow you to make conclusions on the safety of the existing welded arrangement, and the appropriateness of any and all loading and system assumptions you have made. The analysis must be based on fatigue loading, and the calculations will be both hand calculations and ANSYS analysis.

Detailed technical drawings of the welded component are also to be produced using Solidworks (refer to CRA).

You can work in a group of up to 4 people in choosing your welded component (indicate your group on your submission) but each person must carry out the audit ON THEIR OWN and submit an individual report and drawings to TurnItIn by the due date (this means they can’t be similar to, or copied from, one another as detected by TurnItIn, refer to https://www.citewrite.qut.edu.au/). Examples of welded system you could choose to analyse include, but are not limited to:

−A car tow-bar (normally a welded SHS type design).

−Gym weight machines or equipment, either at home or in a commercial gym.

−Machines and equipment in a workshop, mechanics shop, or industrial setting (access through existing relationships or work).

−Welded tube bicycle.

−Loaded components on an aluminium boat.

−Cleats and members in a civil application with variable loading (like a steel walkway).

−Other welded components on a car or motorbike.

−Systems and components on the QUT Motorsport FSAE car (if having existing membership of, or relationship with, the team).

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2. Report

The report for this assignment must be a concise summary of the design audit carried out. It must contain the following sections and content:

Introduction Section
This section should include a concise summary of the purpose of the design audit as it pertains to your machine, details on the system being analysed including broad function and a key photo or two (use correct figure labelling and put multiple photos side-by-side with labels to save space and enhance impact). Also include broadly what will be contained in the design audit document (section summary). It is the formal report equivalent of the “Given” section from lectures/tutorials. Length: 0.5-page 11pt font maximum including figures.

Functional Analysis Section
This should include a high-quality sketch of your welded system with dimensions of all key components and the weld group itself and an indication of load directions and magnitudes. This is the point where each possible critical loading scenario should be discussed, including force magnitudes, and directions, and time series data (i.e. is it cyclic between F and -F, or F and 0, or constant etc., at what angle is it and does that change, and what are the loading magnitudes and variations for each critical load case – use diagrams). At this point, also justify which loading scenario you are to analyze in the rest of the report. This is the formal report equivalent of the “Schematic” section from lectures/tutorials. Length: 1.5-page 11pt font maximum including figures.

Design Assumptions and Analysis Scope Section
In this section, you should state all design assumptions and decisions that are being made before the analysis, as well as the scope of the analysis, materials, weld size, mode and distribution of loadings (following on from previous section discussion), and any other choices or assumptions that are necessary including relating to load cycles based on system duty. This is the formal report equivalent of the “Assumptions” section from lectures/tutorials but requires detailed justification on each point to support why or how that assumption was made. Length: 1-page 11pt font maximum including figures.

Detailed Welded Joint Analysis Section
In this section, you must concisely summarise the whole design audit calculation. It should include:

−A high quality FBD of the system with all force values determined based on the worst-case loading scenario chosen.

−A reduction of that system to a single welded joint and the resultant loading at the weld group centroid.

−Full hand calculation of weld stresses on the bases of worst-case loading scenarios. If the worst case is not clear, carry out test calculations for multiple cases.

−Weld fatigue failure analysis using AM-Diagram.

−Summary of resulting chosen metric (size, material, or FOS) and its comparison to actual.

−ANSYS analysis of the same system including FBD showing boundary condition set-up and type of model run.

−Comparison of ANSYS and hand calculations.

This is the formal report equivalent of the “Solution or Analysis” section from lectures/tutorials. Length: 15-pages 11pt font maximum including figures (should only need 10 pages but 15 is allowed for those with complicated weld groups, or multiple calculations with different materials/assumptions etc.).

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Recommendations and Conclusions Section
A section summarising the findings relating to safety of the weld group. Refer to the technical drawings in Appendix A. Also include any discussion of design choices made and how they affected the results. Discuss discrepancies and errors between the critical dimensions calculated, and those of the actual weld group being analysed. IF MAJOR DISCREPANCIES WERE FOUND, RE-DO THE ANALYSIS WITH DIFFERENT OR LESS CONSERVATIVE ASSUMPTIONS. CRITERIA FOR REPEATING ANALYSIS: YOUR FOUND WELD SIZE IS ±25% OF ACTUAL WELD SIZE, MATERIAL IS UN-REALISTIC, OR FOS <1 OR >6. Length: 1-page 11pt font maximum including figures.

Appendix A: Technical Drawings
Full technical drawing of the existing welded group and main component held by the weld, produced using

Solidworks and including:

Primary Drawing: Assembly of the whole system (orthographic, section if needed, shaded isometric) with full detailed annotations on weld size (with correct weld designation arrows), notes on welding rod type, and dimensions on weld positions only. This assembly should have all welded components (i.e. plates / brackets / members). If one of the welded components is a large steel structure that continues outside of the direct loading consideration (like for example the chassis of a car that a tow-bar is connected to, or long sections of RHS that might make up a piece of gym equipment), you can draw an indicative section of that component and use break lines to indicate its continuation (see example below). The drawing should also have a BOM and title block with appropriate details.

Figure 1: Example of large system using break lines to indicate continuation of components [Ref: http://fgg-

web.fgg.uni-lj.si/~/pmoze/esdep/media/wg11/f0110005.jpg].

Secondary Drawings: Any other details that might be necessary for understanding your system. This could be an explosion or specific dimensions of weld group alone.

All drawings must be produced as a PDF from Solidworks and appended to the PDF of your report (I.E. NOT CUT AND PASTE INTO WORD, THAT PRODUCES TERRIBLE QUALITY DRAWINGS). A3 drawing size is appropriate.

THE REMAINING PAGES OF THIS DOCUMENT CONTAIN THE SPECIFIC CRA FOR THE ASSESSMENT TASK

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A. Writing Skills and effectiveness of the document 10/40%

CRITERIA STANDARDS
7 (High Distinction) 6 (Distinction) 5 (Credit) 4 (Pass) 3 and below (Fail)

A1. Correct use All sentences are clear and well-
of sentence constructed communicating a
structure, single clear idea. All sections
grammar and contain sentences that are
paragraphs grammatically correct with proper

(2%) use of commas. Every paragraph

has a clear purpose that is relevant to its position in the document. Every paragraph in the document has a topic sentence, 3 to 5 supporting sentences, and a summary sentence. Separation of paragraphs is logical and ensures the coherent flow of the document.

All sentences are clear and well-constructed communicating a single clear idea. Only very minor grammatical errors. Most paragraphs have a clear purpose that is relevant to its position in the document. Most paragraphs in the document have topic sentences, 3 to 5 supporting sentences, and a summary sentence.

Most sentences are clear and well-constructed communicating a single clear idea. Occasional grammatical errors. Some redundant paragraphs but mostly purposeful. Occasional examples of incorrectly structured paragraphs or paragraphs that are too long or short.

Some confused sentences but mostly well-constructed and clear. Frequent grammatical errors. Common examples of paragraphs that are confusing or redundant. Multiple incorrectly structured paragraphs or paragraphs that are too long or short.

Issues with confusing sentences. Clear grammatical errors. Poor paragraph structuring and largely unclear ideas in significant proportions of the document. Paragraphs seem to be devoid of structure.

A2. Strong High quality figures and images
pictorial used extensively to replace text or
communication support concise ideas. NO PAGE
and use of LINES OR COLOURED
figures and BACKGROUND FROM SCANNING
correct VISIBLE (i.e. edit any hand sketches
captioning (7%) to look professional). ANSYS figures
all follow required guidelines.
Correct captioning (tables above,
figures below, consistent
numbering). Every figure serves a
purpose and is referred to directly
in the text.

High quality figures and images used to replace text in some instances or support concise ideas. NO PAGE LINES OR COLOURED BACKGROUND FROM SCANNING VISIBLE (i.e. edit any hand sketches to look professional). ANSYS figures all follow required guidelines. Correct captioning. Almost all figures serve a purpose and are referred to directly in the text.

Good figures and images used and mostly support ideas. ANSYS figures mostly follow required guidelines. Mostly correct captioning. Almost all figures serve a purpose and are referred to directly in the text.

Passable figures and images used. ANSYS figures only partially meet guidelines. Some incorrect captioning. Some figures serve a purpose where others do not. Some are not referred to directly in the text.

Poor quality or insufficient figures. ANSYS figures poorly created. Wrong or missing captioning. Very little purpose to those that are provided. No text reference to figures.

A3. Report All required headings are
structure incorporated within the report. All

follows the content is appropriate, and
headings and sections flow coherently from one

content to the next. All page limits adhered

required (1%) to.

All required headings are incorporated within the report. All content is appropriate and mostly flow well. All page limits adhered to.

All required headings are incorporated within the report. Most of the content is appropriate. Page limits mostly adhered to (±1-page total).

All required headings are incorporated within the report. Some missing or redundant content. Page loosely adhered to (±2-page total).

Missing headings, poorly structured content, or significant deviation from the word limit.

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B. Quality of content and analysis carried out 25/40%

CRITERIA STANDARDS
7 (High Distinction) 6 (Distinction) 5 (Credit) 4 (Pass) 3 and below (Fail)

B1. Introduction Concise summary of purpose and
Section (1%) context, including clear detail on

machine and weld group being analysed with high quality figures, as well as outline of the design audit document. Weld group chosen is complex shape (>= 3 segments), and under fatigue loading.

Good summary of purpose and context, including detail on machine and weld group being analysed with some figures, as well as outline of the design audit document. Weld group chosen is complex shape (>= 2 segments), and under fatigue loading.

Good summary of purpose and context, including detail on weld group being analysed with some figures. Weld group chosen is under fatigue.

Some discussion of purpose Poor section with

and/or context, including little purpose or
detail on weld group being context.
analysed. Weld analysis can Inappropriate weld
be carried out, but loading is group selection.
trivial or static.

B2. Functional High quality schematic with all
Analysis Section (2%) external loads indicated. All major
loading scenarios discussed with
calculation/ estimation of actual
load values in each case including
direction and time history, as well
as good quality diagrams to
communicate the scenarios.
Appropriate choice and justification
of load case to analyse.
B3. Design General assumptions included.
Assumptions and Material, weld size and shape all
Analysis Scope appropriate and determined
Section (1%) through inspection and research
and verified (references stated and
referenced correctly, IEEE) and
related to the necessary analytical
approaches to be implemented.
Any other necessary assumptions
included. Section is a detailed
discussion of the assumptions and
their basis, 1 page in length.

High quality schematic with all external loads indicated. Most major loading scenarios discussed with calculation/ estimation of actual load values in each case including direction and time history, and some diagrams to communicate the scenarios. Appropriate choice and justification of load case to analyse.

General assumptions included. Material, weld size and shape all appropriate. All determined through either research or approximation (references made). Any other necessary assumptions included. Section is an appropriate discussion of the assumptions and their basis, >0.75 pages in length.

Clear schematic with all external loads indicated. At least two loading scenarios discussed with calculation/ estimation of actual load values in each case including direction and time history. Appropriate choice of load case to analyse with some justification.

General assumptions included. Material, weld size and shape all reasonable. Values mostly approximated based on good engineering practice (little or no research). Section discusses some basis for the assumptions, >0.5 pages in length.

Clear schematic with all Poor or missing
external loads indicated. One schematic. Major
loading scenario discussed omissions in terms of
with calculation/ estimation known load cases, or
of actual load values function of the
including direction and time machine.
history. Load case Inappropriate or non-
appropriate to analyse. critical load case
chosen.

General assumptions Missing general
included. Material, weld size assumptions, or no or
and shape passable but some poor material/ size/
details omitted or shape/ conditions
overlooked. Values all specified.
approximated. Section has
minimal discussion < 0.5 pages in length. 5 of 7 CRITERIA STANDARDS 7 (High Distinction) 6 (Distinction) 5 (Credit) 4 (Pass) 3 and below (Fail) B4. Detailed Analysis Section B4a. System Force A high quality FBD of the system No FBD or completely Analysis (3%) with all force values determined wrong or significant based on the worst-case loading errors in reaction scenario chosen. All load and  Quality and Correctness of Calculation  calculations. reaction calculations correct. FBD drawn perfectly (in equilibrium and completely free) with high quality diagrams. Time history of loading clearly described. B4b. Weld Group A reduction of that system to a Significant errors in Joint Loading (2%) single welded joint and the the calculation of resultant loading at the weld group centroid joint loads, centroid, where those forces are or missing modes of again calculated perfectly based on  Quality and Correctness of Calculation  loading. the correct centroid position, and a clear understanding of the whole system and modes of loading present. B4c. Full Hand Determination of all components of Major errors in stress Calculation for Stress applied stress, von Mises stress, calculation, missing (4%) and stress concentration for the steps, missing weld group and loading scenario, working, or poor including separate group stress  Quality and Correctness of Calculation  understanding of vector analysis proceeding correct process. superposition. Calculation completely correct, and identification of critical zone done correctly. B4d. Full by Hand Application of fatigue theory Fatigue Analysis (3%) including determination of alternating and mean components of stress, use of AM diagram, and analysis on the basis of both Goodman and Yield lines. Calculation procedure carried out perfectly and calculations completely correct. Missing fatigue calculations, or major errors ins process or implementation. Quality and Correctness of Calculation  B4e. Summary of Concise and pictorial summary of Hand Calculation result found through hand result (1%) calculations, and comparison to the actual weld group within the machine or system. Discussion of specific aspects of the hand calculation that may have caused differences presented. Summary of result found through hand calculations, and comparison to the actual weld group within the machine or system. Discussion of some aspects of the hand calculation that may have caused differences presented. Summary of result found Summary of result found No summary or very through hand calculations, and through hand calculations. poorly written comparison to the actual weld summary. group within the machine or system. 6 of 7 CRITERIA STANDARDS 7 (High Distinction) 6 (Distinction) 5 (Credit) 4 (Pass) 3 and below (Fail) B4f. Full ANSYS Detailed structural and fatigue Fatigue Analysis (6%) analysis carried out on the weld group using ANSYS and following the weld analysis procedure presented in the week 5 lecture and week 7 CLB. Modelling approach carefully and concisely summarised (FBD, contacts, materials, etc.), mesh size appropriate with resolution study presented, detailed results on stress communicated, detailed results on fatigue communicated. Discussion of results and choices insightful. Detailed structural and fatigue analysis carried out on the weld group using ANSYS and following the weld analysis procedure presented in the week 5 lecture and week 7 CLB. Modelling approach summarised (FBD, contacts, materials, etc.), mesh size appropriate with resolution study presented, detailed results on stress communicated, detailed results on fatigue communicated. Some discussion of results and choices. Structural and fatigue analysis carried out on the weld group using ANSYS and following the weld analysis procedure presented in the week 5 lecture and week 7 CLB. Some summary of modelling approach, mesh size shown, stress results communicated, fatigue results communicated. Structural analysis carried out Missing section, or on the weld group using major errors in result ANSYS and mostly following or approach or the weld analysis procedure communication of presented in classes. Stress result. results communicated. B4g. Comparison Concise and pictorial summary of between ANSYS, result found through FEA, and Hand Calc, and Actual comparison to the actual weld (1%) group within the machine or system. Discussion of specific aspects of the ANSYS calculation that may have caused differences presented. Summary of result found through FEA, and comparison to the actual weld group within the machine or system. Discussion of some aspects of the ANSYS calculation that may have caused differences presented. Summary of result found Summary of result found No summary or very through FEA, and comparison through FEA. poorly written to the actual weld group within summary. the machine or system. B5. Result concisely summarised. Result summarised. Choices Result summarised. Choices Result summarised. Choices No result summary or Recommendations Choices clearly and coherently discussed. Difference/ agreement discussed. Difference/ discussed. Difference/ not discussion of and Conclusions discussed. Difference/ agreement in resulting design metric (size/ agreement in resulting design agreement in resulting design choices, or no Section (1%) in resulting design metric (size/ material/ FOS) and actual weld metric (size/ material/ FOS) and metric (size/ material/ FOS) analysis of difference material/ FOS) and actual weld group discussed and reasonable actual weld group discussed and actual weld group noted between calculation group discussed and insightful and reasoning for discrepancies and some reasoning for but missing detailed and actual. correct reasoning for discrepancies identified. Any recalculation done discrepancies identified. consideration. identified. Any recalculation done to better represent real scenario. to better represent real scenario. 7 of 7 C. Technical drawing appendix 5/40% CRITERIA STANDARDS 7 (High Distinction) 6 (Distinction) 5 (Credit) 4 (Pass) 3 and below (Fail) C1. Drawing Layout Title block used correctly with full and Title Block (0.5%) author and part details. No dimensions or drawing aspects outside of the boarder or overlapping with one another. Perfectly clear drawing in every way. Produced using Solidworks PDF save. Title block used correctly with full author and part details. No dimensions or drawing aspects outside of the boarder or overlapping. Produced using Solidworks PDF save. Title block used correctly with full author and part details. One or two minor overlaps or areas of confused lines or hard to read parts, but overall clear. Produced using Solidworks PDF save. Title block used correctly with full author and part details. Some confusing areas but mostly legible. Produced using Solidworks PDF save. No title block or cut and paste into Word rather than produced correctly using Solidworks, or highly confusing and poorly laid out drawings. C2. View Selection Sufficient views chosen in each and Positioning technical drawing, adhering to (0.5%) those required in the outline. Additional section and detail views used professionally and to perfect effect. C3. Primary Drawing Excellent quality assembly (2%)* drawing of whole system, with perfect component and weld detail. All views of a professional engineering quality. Comprehensive dimensions for the weld and weld positions and perfect annotations. Sufficient views chosen in each technical drawing, adhering to those required in the outline. Additional section and detail views used. High quality assembly drawing of whole system, with perfect component and weld detail. All views sufficient to communicate design. Detailed dimensions for the weld and weld positions and adequate annotations. Sufficient views chosen in most technical drawings (1 drawing with a problem), adhering to those required in the outline. Either a section view or a detail view used. Good quality assembly drawing of whole system, with most component and weld details shown. Most views sufficient to communicate design. Some dimensions and annotations. Sufficient views chosen in Insufficient views chosen to some technical drawings (>1 communicate the bolt group
drawing with a problem), and part details.
adhering to those required in
the outline.
Passable assembly drawing of Major issues with quality,
whole system, with only number of parts, views,
some component or weld dimensioning, or no
details difficult to distinguish. dimensions.
Some redundant or unclear
views, but mostly
appropriate. Minimal
dimensions and annotations.

C4. Secondary Part or technical drawing of a
Drawing (2%) professional engineering level,
including all required views and
dimensions, ready for
manufacture.

Part or technical drawing of a high quality, including all required views and dimensions, mostly ready for manufacture, only minor corrections.

Part or technical drawing of a good quality with some key issues or areas needing correction before drawing approval (either multiple small issues like missing dimensions, or one major issue like a missing view).

Part or technical drawing of a

passable quality but requiring

major revision before
approval for manufacture
(missing dimensions, missing
views, unclear
communication).

Poor quality drawings, needing significant work to attain a level appropriate for a professional engineer.

*Note, if all details can be captures in the primary drawing, this section is worth 4%

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