1. Aim and learning outcomes
The aim of the assignment is to assess students’ ability to effectively and correctly apply computer aided analysis and FEA to design and analyse structures.
Learning outcomes for the assessment are as follows:
• Demonstrate knowledge and understanding of how structures respond to loading actions in terms of deformation and internal stresses under serviceability loads and up to failure
• Demonstrate knowledge and understanding of the methods to conduct elastic analysis of framed structures choosing appropriate models
• Be able to apply concepts and theories of structural analysis to design and verify structures using concept design, approximate analysis and a computer code
• Develop competence in the design of structures and be able to discuss the design of a structure in a technical report
• Develop competence in the use of computer aided design and analysis.
2. The problem
A preliminary design and analysis is required for a building in the north-east area of Hyde Park, London, which will host a space for exhibition, a café and a recreation area for children.
The following design constraints and objectives are given.
• The maximum area which can be used is a 50 x 50 m2 square located as shown in Figure 1.
• The maximum height of the building is 11 m above ground level.
• The maximum number of floors which the building can have is 2.
• The building should have three indoor areas, each 250 m2 in area for: (i) exhibition space (ii) a café and (iii) a children’s recreation area.
• The budget is reasonably high but not infinite.
• A reasonable strength-to-weight ratio should be considered.
• Regardless of the structure to be designed, you should assume that a very stiff and sufficiently strong reinforced-concrete raft foundation is used with its top surface 1 meter below ground level. The raft foundation should neither be calculated nor included in the analysis apart from assuming that it’s bending and membrane stiffness values are infinite and any settlement in the ground can be ignored.
• It can be assumed that the ground level is flat after the works are completed.
3. Submission and description of tasks
Your task is to create a computer model of the structure for design and analysis using SAP2000 and to produce a written report.
The report will feature 6 sections plus a cover page, as summarised in the table below:
Section Description Page limit
Cover Cover page with name and title 1 page
1 Design Description 4 pages
2 Definition of model and calcs. of loads 2 pages
3 Qualitative and approximate analysis 2 pages
4 Selected results – design and analysis 3 pages
5 Conclusions ½ page
6 References Unlimited
Cover page (1 page)
To include:
• title of the assignment,
• Student name and ID number
• 3D picture of the structural model exported from SAP2000.
Section 1 – Design Description (4 pages maximum)
Section 1.1 – Drawings (3 pages maximum)
One plan view and two cross sections.
Section 1.2 – Description of the structure (1 page maximum)
In a concise and clear manner, preferably using bullet points, describe:
• The proposed structure
• How it meets the design objectives and constraints.
• Brief description of the joints, so that later in Section 2.1 the model assumptions (e.g. restraints, end-releases), can be justified.
Important points to note:
1. No detailed drawing of any architectural design should be included in the report.
2. The main aspects of the non-structural design and the floor system(s) should only be described in the text of this section in relation to how they affected or inspired the structural design and with a view to providing enough information to justify the computation of the values of the permanent loads in Section 2.2.
3. If you have had any source of inspiration for your design include few lines of acknowledgement of this and quote and include in the list of references any relevant book, article or website as appropriate, but do not add any pictures. You are not specifically asked to be inspired by any existing structure whereby it would be equally accepted that your design is entirely original or that you cannot recognise any clear source of inspiration for it.
Section 2 – Definition of model and calculations of loads (2 pages maximum in total )
Section 2.1 – Model assumptions (1/2 page maximum)
To include:
1. Type of elements used (e.g., frame/cable, shell, etc ..),
2. Whether or not end releases are used and why,
3. The restraints applied,
4. Assumptions influenced by joint selections.
Section 2.2 – Applied loads (1 page maximum, including 100 words maximum. Use equations!)
• Load cases considered,
• Load combinations used,
• Estimate floor dimensions by approximate analysis and/or based on the manufacturer specifications (e.g., if precast floors are used) for the purpose of determining the permanent loads on the structure.
• Only vertical loads (including snow) should be quantitatively considered in the analysis. Permanent and imposed loads should be estimated based on the guidance given in Eurocode 1.
Section 2.3 – Wind load (1/2 page maximum, and use bullet points)
In this section the wind action should be discussed qualitatively by describing how it can be included in the analysis and whether it is expected that the structural scheme used would be effective (possibly changing some cross section dimensions) or some major changes in the structural design are required.
Section 3 – Qualitative and approximate analysis (2 pages maximum, 150 words maximum, for the rest use sketches and equations)
In this section, describe the qualitative structural behaviour and provide an approximate estimation of the order of magnitude of two quantities which can be one of the three cases below:
• One significant stress-resultant and one significant reaction component,
• Two significant stress-resultants,
• Two significant reaction components.
You must include simple sketches, which can be hand-drawn.
Aspects of the structural behaviour that you are expected to consider in this section include but are not necessarily limited to:
• whether structural members operate mainly or completely in bending, in tension/compression (or as membrane), or with a combination of the two;
• whether the overall behaviour of the structure can be approximated with a simplified scheme or with a clever combination of schemes, possibly making efficient use of fundamental concepts such as the flexibility method (i.e. force method) and/or the stiffness method (i.e. displacement method);
• whether part of the deformed configuration of the structure can be qualitatively predicted with sound arguments.
Section 4 – Selected results of the design and analysis (3 pages maximum, 150 words maximum and use diagrams and tables)
In this section, select suitable results in terms of stress-resultant diagrams/values and, if useful, reactions should be reported. In particular you should include:
• a comparison between the qualitative aspect of the results and the qualitative behaviour discussed in Section 3;
• a comparison between the values of the stress-resultant(s) and/or reaction(s) computed in an approximate way in Section 3 and those obtained using SAP2000 and reported in this Section.
If useful to validate the approximate analysis of Section 3, in this section you can also report selected results in terms of deformed configuration.
Only the cross-section dimensions of the structural elements used should be designed and the results of the verification of such dimensions should be reported in this section for not more than 3 critical cross-sections. Such dimensions should be computed and verified using appropriate but simple and approximate methods.
Section 5 – Conclusions (half page maximum)
• Summary of the project
Section 6 – References (no limits)
4. Assessment criteria
The following criteria will be used for assessment:
Criterion Weight Relevant parts of the submission
1 Correct creation of the model. Correct choice and justification of the model assumptions. Correct determination and application of loading actions and restraints. Correct qualitative discussion of the wind load. 30% Model file;
Section 2.
2 Correct description of the structural behaviour. 15% Section 3
3 Approximate estimation of two stress resultants or reaction components. 10% Section 3
4 Correct discussion of the results in comparison with the approximate analysis of Section 3 10% Section 4
5 Fulfilment of design objectives and constraints and creativity of the design 15% Section 1
6 Presentation and overall clarity of the report. Compliance with page limits.
Completeness of the report .
Absence of very significant errors or unreasonable arguments, statements, design choices or conclusions . 20% Entire report, including cover page, all sections and reference.
5. Indicative reading list
1. D.M. Brohn. Understanding Structural Analysis.
2. R.C. Coates, M.G. Coutie and F.K. Kong. Structural Analysis. Chapman & Hall, 1988.
3. M.S.Williams and J.D.Todd. 2000. Structures: theory and analysis, Macmillan
4. A. Ghali, A.M. Neville. Structural Analysis. A Unified Classical and Matrix Approach. Chapman & Hall, 1983.
5. T.H.G. Megson. Structural and Stress Analysis. Elsevier Butterworth Heineman, 2005.
6. Hambly, E. (1994) Structural analysis by example, Archimedes, Berkhampsted
7. Lecture notes provided on u-link
8. Web links provided on u-link
9. SAP2000 User Manual.
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