Esfuerzos en Vigas _ Uniones Remachadas o Roblonadas

ESFUERZOS EN VIGAS – UNIONES

EVALUACIÓN DE 3a UNIDAD P1. Diseñar la sección e la !i"a #$e se %$es&ra' sa(ien) #$e *+

,( - ae%s #$e la /a&i"a 0)r 1e2ión es e 344 5"6c% 7 - la /a&i"a 0)r c)r&e 37 5"6c%7.

Solución:

8∑ Fy =0 RB + RD = 2(2) + 4 + (4/2) (6) RB + RD = 20 T

8∑ MD = 0 (6/2) (4) (6/3) + 4(3) - RB (6) + (2) (2) (7) = 0 RB = 1067 RD = !33

Analizando Tramos:

"

Tramo AB : 0 ≤ x ≤ 2

∑ F#= 0 -2$ % # = 0 # = -2$

∑M=0 2$ (x/2)+ M = 0 M= -2 $2 / 2 M = -$2

" Tramo BC: 2 ≤ x ≤ 5

∑ F# = 0

-(2) (2) + 1067 % ( 96: ; ($ % 2) (2<7;67- # =0 &= - =2<7;,7+ 667 ∑ M= 0

2(2) ($ -1) % 1067 ($ % 2) + (4/6) ($ % 2)( $-2)/2 ($-2)/3+ M =0 M= -4 ($ % 1) + 1067 ($ % 2) - ($-2)3 /!

"

Tramo CD: 5 ≤ x ≤ 8 ∑ F# = 0

< (2) (2) + 10 67 - 4 % ( 96:; ($ - 2)  =2<7;67 - & =0 &=-

=2<7;3 / , + 267

∑M=0

(2)(2)($ % 1) % 1067 ($ % 2) + 4 ($ % ') +( 4/6)($ % 2) ( x-2)/2 (x-2)/3+M = 0 M = - =2<7;3 / > - 4 ($ % 1) + 1067 ($ % 2) % 4 ($ -')

AB: 0 ≤ x ≤ 2

&= - 2 M= -2 BC: 2 ≤ x ≤ 5

&= - + 667 M= -4 ($ % 1) + 1067 ($ % 2) -

CD: 5 ≤ x ≤ 8

& = - + 267 M= - - 4 ($ % 1) + 1067 ($ % 2) % 4 ($ - ') M *$= 13 T-  ?= = 100 ,/c2  = = 12 ,/c2

.= .= .= .= M = 13 T-  M = 13 $ , % c =

& = 667 T & = 667 $ ,   =  $ 3   = 3

?+ 344 5"6c%

 = 12 ,/ c 2

7

?+ 344 +

 = = ()

37 +

=

344 + ( + 74.@9 c%

co,o  5yo:  = 20 c  = 60 c

12 =

( + 3:.: c%