Reference no: EM132375368

General Information

This assessment is designed to assess your knowledge on design of timber structures from SEV323. You will find the class/seminar content and design standards to be excellent resources for completion of this assessment. This assessment item relates to the unit learning outcomes (ULO's) 1, 3 and 4.

Each student is required to prepare a calculation report which details the full design procedure for each of the design scenario.

Design report shall include clear and concise detailed solving process, neat and clear sketches (if necessary) and concise written summaries as required by the assessment. Ensure you clearly identify solutions (e.g., underline each solution). Students shall ensure that they use appropriate significant figures and SI units at all times.

(1) Tension Design

The main roof trusses in a tourist park building at Nambour (100 km North of Brisbane, Queensland) will be fabricated from 38 mm thick unseasoned F7 hardwood material (locally sourced). Connections will be nailed gusset plates at each end of the member. The roof truss will span 12 m, will be 3 m apart and will support purlins and steel sheet roofing.

A tension chord in the trusses has the following unfactored loads:

Permanent action                              30 kN (tension)

Imposed action (construction)             5.5 kN (tension)

Ultimate wind load                             26.6 kN (compression)

Ultimate wind load                             6.6 kN (tension)

a) Find the factored strength limit state load combinations for the design of the chord as a tension member. Consider at least the following combinations:
• Permanent action plus longer term component of the imposed action
• Permanent action plus full shorter term imposed action
• Permanent action plus ultimate wind load (tension)
• Permanent action plus the effect of ultimate wind load (compression)

b) For the strength limit state, select the appropriate size material from the sizes given in the following Table 1. (It is best to make the whole truss out of the same thickness material- in this case, 38 mm thickness)

c) Demonstrate (with calculation) that the selected size has sufficient capacity to resist the design load.