Question

t 4 mm An L-shaped bracket lying in a horizontal plane supports a load P= 600 N (see figure). The bracket has a hollow rectangular cross section with thickness t=4 mm and outer dimensions b = 50 mm and h-90 mm. The centerline lengths of the arms are b-500 mm and b 750 mm. (a) Calculate the normal stress o and the shear stress t at point A, which is located on the top of the bracket at the support (8 pts), (b) Draw these stresses on a small element at A (2 pts.). b500 mm h-90 mn b2 750 mm b 50 mm P= 600 N

Answer 1

Given :- load (P) = 600N thickness (1) a umm Outer dimensions (6) =50 mm h: 90 mm Centerline lengths of the arms are b1 = 5 comm: 62 = 750mm stress resultants at the support are Toaque (1) = pbz = 600 (150) -4.5 X10 N-mm Moment (M) - pbi = COD (500) = 3x105N-mm Shear Toste MVEP=600N Section properties For torsion Am = (b-2)(h) = 150-4) (90-0) 5 3956 mm For bending conly = 9012 = 45 mm Is Viabh3o Yo (50) (90)3

= 3,037, 500 many Stress at point a on the top of the bracket are e-I 2t Am e= 4.5x105 2 (4)(3956) le = 1.218 Mpa -= MC 7 - 3x105 x ups 3,037,500 -E 4. uumpa sa=0 y=-.4.07mpa Txy=- =14.218 Hpa Normal stress at a Tosunumpa Shear stress at ase=14.218 Mpa)

@ stresses on small element. A ЛЧ: ЧИМПа 14.08MPOL