Date of Publication :8th March 2017
Abstract: Trusses are triangular frame works, consisting of essentially axially loaded member which are more efficient in resisting external loads since the cross section is nearly uniformly stressed.Trusses are used in roofs of single storey industrial buildings and multi storey industrial buildings. The loads on the roof truss are dead load, live load, wind load and earthquake load. Trusses are also used to support long span floors of multi storey building to resist gravity load. The axial forces in members are calculated by taking these loadings and their critical combinations.For design of trusses, effect of wind force is predominant to calculate the member forces. SP 38(S&T):1987-provides designing for structures with steel roof trusses and their weight comparison. It gives details of specific roof truss configuration. This Paper represents analysis and design of roof trusses whose configuration are other than that specified in SP 38(S&T):1987. However their span to depth ratio is same as the truss configuration given in SP 38(S&T):1987. The trusses which has been analyzed having span 12m, 18m and 24 m and angle section has been used for design purpose. The analysis has been done for three basic wind pressure 100 kg/m2, 150 kg/m2 and 200 kg/m2, So that we can compare the weight of these trusses with A-type roof truss of having same span which is specified in SP 38(S&T):1987.The purpose of this study is to suggest the most feasible truss section, when longer span roof sheets are used. Now a days roof sheets of longer span are available in market. So we can use the configuration which have less number of purlins or wider panel. The truss configurations are distinguished between three categories namely Pitched roof trusses, Parallel chord trusses and Trapezoidal trusses. The advantages and disadvantages of different truss configuration are discussed in detail
Reference :
-
- A. S. Arya, and J. L. Ajmani, “design of steel structure.” Nim Chand and Bros, pp. 571-646, 2001.
- IS 875 (Part 3) (2015), Code of practice for design loads (other than earthquake) for buildings and structures, BIS, New Delhi, India.
- IS 875 (Part 3) (1987), Code of practice for design loads (other than earthquake) for buildings and structures, BIS, New Delhi, India.
- IS 875 (Part 2) (1987), Code of practice for design loads (other than earthquake) for buildings and structures, BIS, New Delhi, India.
- IS 875 (Part 1) (1987), Code of practice for design loads (other than earthquake) for buildings and structures, BIS, New Delhi, India.
- SP: 38(S&T) (1987), Handbook for Typified Design for Structures with Steel Roof Trusses, BIS, New Delhi, India.
- S. K. Dubey, P. Sangamnerkar, and P. Soni, “Analysis of steel roof trusses under normal permeability condition”, Proceedings of National Conference on Advances in steel structures, Res.j. Engineering Sci., pp. 47-49, 2011.
- A. Jayaraman, R. Geethamani, “Design and economical of roof truss and purlins.” International Journal of Engineering Research, vol. 10, no. 3, 2014.