Telechargé par Gingermon

sm10 102 103

publicité
________________________________________________________________________
PROBLEMS (10.102 and 10.103) The compound beam AHB shown in Figs. P10.102 and
10.103 has fixed supports at ends A and B and consists of two members joined by pin connection at H.
Determine all reactions of the beam due to the concentrated load P.
SOLUTION (10.102)
Use Table B.14 (case 1):
RH
H
L/3
A
H
RH
vH = −
+ H
B
2L/3
RH ( L 3)3
R L3
=− H
3EI
81EI
θC
(1)
B
C
P( L 3) 2
PL2
θC =
=
2 EI
18 EI
3
R (2 L 3) P( L 3)3 PL2 L
vH = H
−
−
( )
3EI
3EI
18EI 3
8 RH L3
5 PL3
=
−
81 EI
162 EI
(2)
From Eqs.(1) and (2):
5
RH = P
18
Then
A
MA
5
P↑
18
5
MA =
PL
54
5
P
18
L/3
RA =
H
RA
5
P
18
P
C
MB
B
RB
13
P↑
18
8
MB =
PL
54
RB =
Continued on next slide
Excerpts from this work may be reproduced by instructors for distribution on a not-for-profit basis for testing or
instructional purposes only to students enrolled in courses for which the textbook has been adopted. Any other
reproduction or translation of this work beyond that permitted by Sections 107 or 108 of the 1976 United States
Copyright Act without the permission of the copyright owner is unlawful.
SOLUTION (10.103)
Use Table B.14 (case 1):
P
A
MA
Loading I
( vH ) L =
( P − RH ) L3
3EI
MB Loading II
( vH ) R =
RH a 3
3EI
H
L
RH
RA
RH
H
a
B
RB
Since (vH ) L = (vH ) R :
( P − RH ) L3 RH a 3
=
,
3EI
3EI
or
PL3
RH = 3
L + a3
Statics:
Loading I:
PL3 − RH L3 = RH a 3
Pa 3
∑ Fy = 0 : RA = L3 + a3 ↑
∑M
A
= 0 : M A = ( P − PH ) =
Pa 3 L
L3 + a 3
Loading II:
Pa 3
↑
L3 + a 3
PL3 a
M
=
M
=
0
:
∑ B
B
L3 + a 3
∑ Fy = 0 : RB =
Excerpts from this work may be reproduced by instructors for distribution on a not-for-profit basis for testing or
instructional purposes only to students enrolled in courses for which the textbook has been adopted. Any other
reproduction or translation of this work beyond that permitted by Sections 107 or 108 of the 1976 United States
Copyright Act without the permission of the copyright owner is unlawful.
Téléchargement