The Core Engineers

Design of Build-Up Section: This is a compression member. The slenderness ratio of the each member between the connections should not be greater then 40 nor greater than 0.6 times the most unfavorable slenderness ratio of the whole strut. In no case should the spacing of tackling rivets in a lined exceed 600 mm for such members like tee angles, channels or tees placed back to back. For other type of Build-Up Compression Members say where cover-plates are used, the pitch of tackling rivets should not exceed 32.t or 300 mm, whichever is less. When plates are exposed to the weather, the pitch should not exceed 16.t or 200 mm whichever is less. Design Steps: Step 1: Selection of Section Selection of Section Pd = Ae.fcd where,  Ae is Effective Area Pd = 1.5*P #Assumption of fcd, when Pd is given: 1. When Pd > 10 kN    Then fcd 25 MPa to 50 MPa 2. When 100 < Pd < 250 kN    Then fcd 75 MPa to 150 MPa 3. When 250 < Pd < 350 kN    Then fc 100 MPa...

Design Of Roof Truss: If load from purlin, false ceiling etc are applied in between the nodes, then principal rafters or main ties are designed for combined stresses from bending and axial loads. IS 800 - 2007 provides general design procedure for the angle Purlins conforming to steel grade of Fe 410 of O, S, W  and not exceeding slope more than 30 degree based on live load of 750 N/m2. Loads on Trusses: Dead Load, Live Load, Wind Load and Snow Load are types of loads on the truss. The main in Design of Truss in small truss and some Industrial Truss. Dead Load (DL): If spacing of Truss is 4 m and pitch of truss is 1:4 then self weight of the truss is taken as, w = (l/3+6) of plan area .... in kN/m2. Then add all the dead loads with this such as GI sheet, AC sheet and Purlins weight. Then multiply with the plan area to get the actual DL. Live Load(LL): If the angle is less than 10 degree, then the LL will be directly taken as 750 N/m2. If slope of truss is more than 10 degree, live ...

Design of Compression Member: Common hot rolled and build-up steel members used for carrying axial compression, usually fail by flexural buckling. So here we will see how to calculate the design compressive strength comparing to the factored load. The design compressive strength Pd of a member is given as  P<Pd where, Pd is design compressive strength of member. # Design of Compressive Strength (Pd): The design compressive stress, fcd of axially loaded compression members shall be calculated using the following equations: The above is written in short from the IS 800 - 2007, Page 34. For other terms you can refer the IS 800 - 2007, from Cl 7.1.2 which gives the Imperfection Factor,  Effective length of Prismatic Compression Member, Effective Length of Strut, Maximum Value of Slenderness Ratios which are required for the calculation of design of compression members. This written by me in the shortest form possible.

Design of Tension Members: For this we need IS 800 - 2007 Tension members are linear member in which axial forces act to cause elongation. Such member can sustain load upto the ultimate load, which stage they may fail by rupture at a critical section.  The factored design tension (T) in members shall satisfy: T < Td where, Td is Design strength of member. #Td is classified under as for Bolted Connection: 1. Tdg 2. Tdn 3. Tdb Consider Td value whichever is less. 1) Due To Yeild Strength (Tdg): Cl 6.2 Page 32  Tdg = Ag.fy/rmo where, Ag=Gross Area of Cross Section fy=Yeild Stress of Material 2) Due To Rupture of Critical Section (Tdn): Cl 6.3 Page 32 Tdn = 0.9.An.fu/rml where, An=(b-n.dh)t   For Chain Bolting fu=Ultimate Stress of Material Cl 6.3.3 If there is Single Angle Section then, Tdn =(.9Anc.fu/rml) + (beta.Ago.fy/rmo) where, beta=1.4-0.076(w/t)(fy/fu)(bs/Lc) < (fu.rmo/fy.rml)                       ...