Question

65 kN 45 kN/m 35 kN/m 1 m A36 Steel .Factor of safety must be 3.0 with respect to yielding in tension or compression and 3.5 with respect to yielding in shear .Determine which beam will be lightest 1) Draw a shear force and moment diagrams of the beam with maximums shown and non-linear curves sho wn. 2) Tentatively select a beam based on max normal stress 3) Check the tentatively selected beam for max shear 4) Find and identify the locations on the beam where shear and moment can combine to exceed allo wable stresses 5) Find principal stresses at locations identified to ensure allowable stress is not exceeded. 6) Explain how the beam selected is within the factor of safety and the lightest shown

Answer 1

9) A 36 steel , factor σ「safety-3。 fn tension oT compTessior γ+ yielding Ans a SheoT force and moment diagram of beam ig not to scale ST RA 은 3m SF 3S S.62S 80.62s non linear S8.33 K/m Non inear yield strength of A36 steel is 2somR EquivaJent becum 135 KN

momentaboct P 8 o compression affectire Bm3 m actucul for Tonsion affecHt Bm3 m actual shea actual S. f-3.Sx(SF)actu Ans becum is heve B.m is smaller that portion is (DE), having maximur℃7 Ans SF in i secton s not minmu In portion c Bending cmd sheay For can be combined to ex ceed aWowable gtres-