I
B
'kN
PROBLEM6.7
Using the method of joints, deteInline the force in each member of the
k:'i truss shown. State whether each memberis in tension or compression.
,
!
O.9m
L
Ll.2'm-Ll.2
m-J
PROPRIETARY MATERIAL. @ 2007 The McGraw-HilI Companies, Inc. All rights reserved. No part of this Manual may be displayed, reproduced
or distributed in anyfonn or by any means, without the prior written pennission of the publisher. or used beyond the limited distribution to teachers and
educators permitted byMcGraw-Hill for their individual course preparation. If you are a student using this Manual, you are u.singit without permi.~.sion.
-~
~-~"-~~~E
801
*
PROPRIETARY MATERIAL ~ 2007 The McGraw-Hili Companies. Inc. All rights reserved. No part o/t s Manual nIa.Vbe displayed, reproduced
or distributed in anyform or by any means, without the prior written permission of the publisher. or used beyo the limited distribution to teachers and
(:ducator_~
permitted py McGrall'-Hill.for their individual cour.'Iepreparation. If.vou are a .'Itudentusing thi.~ ,\dan lal, .vou are using it lIithout penni.5sion
817
,t:
D'
c.(;
~l-
PROBLEM 6.30
.~
/~
u§:
R\
F
~
;9,
I
For the given loading, detcnninethe zero-fo~cemembersin the truss
shown.
kf
H
PROPRIET..iRY
~L4TERJAL
or di;'lribllled in ari\j()rm or b)
By inspection of joint D,
FDl
o~
By inspection of joint E,
FE!
o~
Then,by inspectionof joint I,
FAl
o~
'pO/or qf t
2007 The McGraw-Hili Compallies, Inc. An. rights reserved. N~vmeans.
withr)ut the prior ~'ritten pel1n~\'sion of the publisher. 0ill
for th"ir individual course preparation If you are a student usi g thi.~.\-fa ual,you are lto~i"git "'ithout~rmis.~io1J
~
used
bey
iS
ad
,\-fanual
the
maybe
lil1JiteddLS.tribUtioo
displayfit.
reprodu(
~
teachers
t
PROPRlET ARY MA TERlAL. '1;:)2007 The McGraw-Hill Companies, Inc. All rights reserved. No part of this Manual may be displayed, reproduced
or distributed in any form or by any means, without the prior written permission of the publisher, or used beyond the limited distribution to teachers and
educators permitted by McGraw-Hill for their individual course preparation If you are a student using this Manual, vou are using it without permission.
8SS
PROPRIETARY MATERIAL
If) 2007 The McGraw-Hili Companies, Inc. All rights reserved. No part ofthi.sl ,\1anual may be displayed. reproduced
or dislribuled in an}'.forfn or b}' any means, wilhout Ihe prior written pennission of the publisher, or u..ed beyon4 the limited distribution to tea£hers and
educators permitteli b.y,WcGrafv-Hill for their individual course preparation. Jfyou are a student using this Manufl, .vou are using it ~'ithout pennission.
865
SOLUTION
FBD SectionACFBD:
I.J~~ ( o.r~
,+,"..
I'
¥oM/
131
~
FFI = 26.196 kN,
\
"/01.1.}
~
r
-PI:
11
(LMD=O:
~;,.
~
FFf = 26.2kN C ~
'2.7 ~
.F
J..4J" '!'
.
'oz.7
t IFy = 0:
f I"I
tl6
Foo = 26.196kN T
~.
!'I;"."'("..~/':"
'C:"
...,:I-.~ I,. .y
~
FBD SectionACFD:
+,0)0;4/ II
,,10.I Ai
f)J
G
.:~1
F
-..$
"';'./9../.-,,,
&
1ST! ~7
i Uy = 0:
,
F
ll?
t;-z
.?h.1",-.tN
-1:F=O
x
8
-~(26.196
",793
FEG= 44.136 kN,
kN + 26.196 kN) = 0
FEG=44.1kNT~
PROPRIETARY MATERIAL. <02007 The McGraw-Hill Companies, Inc. All rights reserved. No part of this Manual may be displayed, reproduce.
or distributed in anyfonn or by any means, without the prior written pennission of the publisher, or used beyond the limited distribution to teachers an.
educators permitted by McGraw-Hill for their individual course preparation. /f )'Ou are a student using this Manual, you are u.~ingil without permis.~ion.
879
'I1cIJ
SOLUTION
FBDFrame:
A~
1!!~
~
(rMA =0:
(0.625m) F -(0.75 m)(4 kN) -(1.25 m)(3 kN) = 0
~T-~:~=~:==,
c..
c
Fx= 10.8kN-
,
a."ts-H'f
-~I:'
J-+b===
F
."::"6.>0'"
3kl'/
= 0..
-"'C"x
Ax-l0.8 kN = 0,
,
,I
Ay -4 kN -3 kN = 0,
,
I
Ax= 10.80kN -".
I
3'@t).Z$~
FBD BF: (I)
FBDABD: (II)
~y
f}."
7:"kN
B
~~
1",3" hV
g
~==;;:~~~
0.25"""'1
, ¥
a:x
(l..
.~
II~
i
0,
2 $""10.\
br
~J'
~Q)(
~.31~/OI
~~~
ey
-~.t~,:
.I" .~,eN
I: (IMc=
0:
II: (WD=O:
(0.375 m)(10.8 kN) -(0.25 m) Bx= 0,
Bx = 16.2kN,
Bx= 16.20kN-~
(0.25 m)(10.8 kN + 16.2kN) + (0.5 m) By- (1.00 m)(7.0 kN) = 0,
By= 0.5 kN,
-~=o:
-10.8 kN -16.20 kN + Dx= 0,
Dx = 27 kN,
7.0 kN -0.5 kN -Dy = 0,
Dy= 6.5 kN,
Dx= 27.0kN-~
PROPRIETARY MATERIAL. <e>2007 The McGraw~Hin Companies, Inc. All rights reserved. No part of this Manual may be displayed, reproduced
or disTributed in anyform or by any means. Without the prior written permission of the publisher. or used beyond the limited distribution to teachers and
educators permitted by McGraw-Hill for their individual course preparation. If you are a student using this Manual. you are !Lyingit without permission.
918
SOLUTION
Member FBDs:
/1,.
I
,,;,-
c"
'-- D
J=-='=iT=:)~
t'"., t"",..
',.
~
j
..;/
1;-'/
~":._.L.:i'::L~'
r
oS"
,~"
l-
";:~N
Solving:
FCr= 9000 N,
Fl)G=6000N
FCF=9.00kNC "4
Foo=6.00kNT
~
..'
1
:",;