Question

P = 20 kN. Calculate the following: 1. The maximum tensile and compressive stresses at the base of the mast A 2. The maximum tensile and compressive stresses at point B of the mast For each stress state at A and B indicate which side of the mast experiences tension and which side experiences compression. 0.25 m m D w 3 m H С. - 0.1 m mast cross section 3 m 60° Р B 584 mm 6 m mast H 600 mm А

Answer 1

which is acting cat G. Effect of W e=(0.25to.) we: B.M. WX (250:) = Beruling moment W compressive stress А q Psingol P a q is UD L (uniformally Di Sasibuted load) plos 60 → Bending will create p sinto → tensile lood (P ck End A is fixed support it will offer B XMA reactions. Ay bag AY GMA moment orgistance AD=18m Equilibirium condition under static AB=om BC = GD = 3m Av + prosto -q (AD) = 0 D Ay + esindo - w taking moment about A wie) Hepcasco), CA – 2140). AB = 0 3 3 Equations AY q w Unknown PO BOX Oknown take w=10KN q- 3KMm (UDL) TAX = -26KH], Jay = 7: 32 KN numeric al valle ed of w.and q we con get uniknolong. taring By

b = We = 1.61 MPa Z 0b2 = [prosto) * AC = 41.416 MPa Di 2 DO 62 MPa mm oc=W A Ot Psino A 1:164 Mia DO=600mm Di=584m A = I 180 2012) 4 I y I= I (DO" DIU) 2 Z=217 3066:614 mm3 A = 1487.6 mm2 64 y = 0/2 poy =(861 +8t) Anstable > Ox = 8b2-06) QR 0x =-64062 = (41.416 MPa -62 MP4 ) UX = 41 MPa tog = 9.774 MPa] Stools at pointo) Note! I tried to solve problem with general vakey, as in the question only pualue was known gone can take any set of values of q and w. Casal Neglect Effect of q, w take p = 20KN 2 A (A) ris (OP) max = psingo + (p casso) x AG A = psingo - (Plosoo). AC Cilj (07) mex s psi'nGo + comp (86) max We = 2 A OĆ) mery psinoo we = A 2