Structural Behaviour and Detailing

Transcription

1 Unit 22: Structural Behaviour and Detailing Unit code: M/601/1282 QCF level: 4 Credit value: 15 Aim This unit enables learners to understand structural concepts and develop skills to determine properties of typical structure materials. Learners will analyse statically determinate structures and design and detail structural elements. Unit abstract Learners will develop the understanding and skills needed to apply the scientific principles associated with the properties and behaviour of structures, loading on structures and load transference to individual elements. The factors that affect structural behaviour and underpin the design of simple structural elements are explored, both in theory and through their application to analysis and design. Learners will also develop skills to translate design calculations into detailed drawings for the purpose of fabrication and construction. Learning outcomes On successful completion of this unit a learner will: 1 Be able to determine the properties of typical structural materials 2 Understand fundamental structural concepts 3 Be able to analyse statically determinate structures 4 Be able to design elements of a structure 5 Be able to detail elements of a structure. 109

2 Unit content 1 Be able to determine the properties of typical structural materials Properties: material classification (malleable, ductile, brittle); elastic and plastic deformation; limits of proportionality; stress; strain; modulus of elasticity Typical structural materials: timber; steel; concrete 2 Understand fundamental structural concepts Fundamental structural concepts: loads, load transfer; structural theory Loads: dead, imposed and wind loads; load configuration; British Standards and codes of practice on loading; limit states and load factors Load transfer: load transference at joints, both restrained and unrestrained, transfer of loading from superstructure to foundation Structural theory: beams, frames and columns; shear force; bending moment; loading and support conditions; conditions of equilibrium; determinate and indeterminate structures; degree of indeterminacy; redundancy 3 Be able to analyse statically determinate structures Statically determinate factors: forces and reactions caused by direct loading; assumptions made when analysing simple structural elements (beams, cantilevers, columns, framed structures); compressive, tensile, shear and bending stresses; permissible stress; factors of safety including partial safety factors in limit state design Analysis: shear force (SF) and bending moment (BM) diagrams; relationship between SF and BM diagrams; forces acting on a frame 4 Be able to design elements of a structure Design issues: properties of sections; variations in bending stress; combination of axial and bending stress Properties of sections: sectional properties (simple beam sections); use of standard formulae or manufacturer s published tables (I xx, I yy, Z xx, Z yy ); in timber, steel and in-situ reinforced concrete Variation in bending stresses: across a section for simply supported beams and cantilevers; axial stress and bending stress on a column (simple concentric and asymmetrical loading) Combinations of axial and bending stresses: maximum stress on column cross-section; maximum stress on simply supported beams (SSBs) subject to both point and uniformly distributed loads; determination of sectional sizes for columns and SSBs Elements of a structure: simply supported reinforced concrete, timber and steel beams; oneway spanning concrete floor slabs; plain masonry columns and walls; timber floor joists to carry a given load over a simply supported span 110

3 5 Be able to detail elements of a structure Detail structural elements: use of manual and computer-aided design (CAD) techniques; structural steel elements; in-situ reinforced concrete elements; structural timber elements Manual and CAD techniques: working drawings; use of standard conventions and practices Structural steel elements: eg roof trusses, portal frames, plate girders including details of node arrangements, cleats, shear plates, bolts, welding requirements, any external fittings In-situ reinforced concrete structural elements: eg column foundations, continuous beams, continuous one-way spanning floor slabs, columns and column/floor intersections including chairs for top steel, cut-off points for reinforcement, distribution reinforcement, cover distances, main bars, distribution bars and links, shear reinforcement, starter bars and kickers for column shutters Structural timber elements: eg joist-to-joist and joist-to-support connections, timber connectors, bolts, plates, gang-nail connectors, cleats, shear rings and hangers, suspended timber floors including strutting, lateral restraint into walls and trimming of openings, grade and type of timber; nominal and actual sizes, sawn, planed and prepared components 111

4 Learning outcomes and assessment criteria Learning outcomes On successful completion of this unit a learner will: LO1 Be able to determine the properties of typical structural materials LO2 Understand fundamental structural concepts Assessment criteria for pass The learner can: 1.1 compare properties of typical structural materials 1.2 calculate stresses and strains applied to typical structural materials 1.3 determine the modulus of elasticity of typical structural materials 2.1 discuss loading conditions for a structure 2.2 illustrate load transfer from superstructure to foundation 2.3 analyse beams, columns and frames using basic structural theory LO3 Be able to analyse statically determinate structures 3.1 discuss the factors to be considered when analysing the elements of a structure 3.2 analyse the forces acting in members of a statically determinate frame 3.3 produce bending moment and shear force diagrams LO4 Be able to design elements of a structure 4.1 produce suitable designs for simply supported beams 4.2 produce suitable designs for a one-way spanning slab in in-situ reinforced concrete 4.3 produce suitable designs for plain masonry columns and walls 4.4 produce suitable designs for timber floor joists LO5 Be able to detail elements of a structure 5.1 produce details of structural steel elements 5.2 produce details of elements of an in-situ reinforced concrete structure 5.3 produce details of structural timber elements 112

5 Guidance Links This unit links with other Edexcel BTEC HN Construction and the Built Environment units, for example: Unit 2: Science and Materials for Construction and the Built Environment Unit 3: Applied Mathematics for Construction and the Built Environment Unit 7: Construction and Maintenance of Buildings Unit 8: Technology of Complex Buildings Unit 26: Properties and Performance of Construction Materials Unit 29: Computer-aided Design for Construction Unit 34: Structural Analysis and Design. The content of this unit has been designed and mapped against the current CIC National Occupational Standards and the current NVQs at levels 4 and 5. Completion of the learning outcomes will contribute knowledge, understanding and skills towards the evidence requirements of the NVQs. See Annexe B for summary of mapping information to NVQs. This unit has also been mapped to illustrate the links to the NQF units. See Annexe D for summary of mapping information to NQF units. Essential requirements Learners require access to experimental and modelling equipment in order to appreciate and understand structural concepts. Access to design and drafting equipment is also essential. It is essential that a culture of health and safety is embedded in all the units to ensure that the learners understand the importance and relevance of health and safety issues. Therefore there should be clearly signposted aspects of current legislation and health, safety and welfare implications throughout the delivery and assessment of this unit. Employer engagement and vocational contexts Tutors should organise site visits, for example to the design sections of consulting firms. To ensure site visits are successful tutors should outline the aims and objectives of the visits, conduct preparatory briefings and encourage learners to review the site visits once completed. Tutors should organise presentations by visiting speakers, for example representatives with structural design backgrounds on current industrial practices. Tutors should use real-life case studies, based on site visits, for part of the assessment for this unit. 113