REMOVAL EXAM
TIMBER DESIGN ALPHA TO OMEGA OMEGA
CLOSED NOTES, HANDOUTS, BOOKS AND HOMEWORKS *Read problems omple!el" a#d are$%ll" be$ore be&'##'#& !o sol(e)
75
Name:_______________________________________ School ID No.:_______________ Name:_______________________________________ No.:_______________ Section: _________________ _________________ ) M%l!'ple C+o'e ( 3 points each)
Instruction: Solved the following problems and write the corresponding letter of your answer on the space provided in the separate answer sheet provided. SIT!ATION 1
A small dam of height h = .! m is constructed of vertical wood beams" as shown in the figure TD-RE001. #he wood beams" which have thic$ness thic$ness t = = %! mm are simply supported by hori&ontal steel beams at A and '. Problem 1 (alculate the ma)imum bending stress if the depth of water is .* m" in +,a.
a. %.*-
b. 6.63
c. !.--
d. .
Problem 2 (ompute the ma)imum shear stress if the depth of water is .* m" in +,a.
a. *./Problem 3
b. 0.29
c. *.!
d. *.
(ompute the ma)imum depth of water if the allowable bending stress is 0. +,a" in m. a. /.!* c. /.-* d. /.0* b. 1.70
SIT!ATION 2
1efer to figure TD-RE002. Span of purlin , L = !.* m Slope 2#op chord3 = /4:5 6 7 Given: Dead load = /** ,a 2inclined3 8ind ,ressure (oefficients: 9ive load = !% ,a 2inclined3 8indward side = *. pressure 8ind load = /00* ,a 9eeward side = *. suction Proper!'es o$ !+e P%rl'# P%rl'# b = %! mm d = /!* /!* mm Weight of wood = wood = !.!- $N;m5 F b = F t t = = /.! +,a E w = %.5/ <,a p = p = -.! +,a F v = /.%! +,a For D L W !oad co"bination, co"bination, a one third third increase increase in the a!!owab!e a!!owab!e stresses is is a!!owed# Problem 4 ind the safe purlin spacing 2m3 for D > 9 load combination. a. 0.5
b. *.
c. *.%
d. *.?
Problem 5 ind the safe purlin spacing 2m3 for D > 9 > 8 where 8 is at the windward side. a. 0.6
Problem 6
b. *.?
c. /.*
d. /.
ind the safe purlin spacing 2m3 for D > 9 > 8 where 8 is at the leeward side. a. 1.0 b. /. c. /.5 d. /.!
SIT!ATION 3
See figureTD-RE003. 'eam A' is simply supported at A and is fi)ed at '. (olumn A( is !* mm s@uare timber with the following properties: $!!owab!e stresses: stresses: 'end 'endin ing g and and tens tensio ion n para parall llel el to the the gra grain in = /.? /.? +,a +,a (omp (ompre ress ssio ion n para parall llel el to the the grai grain n = /5. /5. +,a +,a Shear parallel to the grain = .0* +,a (ompression perpendicular to the grain = 0. +,a +odulus of elasticity = ?.0% <,a %se: & = m L = L = ? m Problem 7 8hat is the allowable concentric load 2$N3 in column A( if both ends are pinconnectedB Sidesway is prevented. Assume ' Assume ' e = /.*. a. // b. 00 d. ?! c. 276 Problem 8 Determine the moment capacity 2$N.m3 of beam A'" if its dimensions and properties are the same in
column A(. a. !!.? Problem
b. !!.5
c. /!%.0
d. 56.77
(alculate the safe uniform load 2$N;m3 including its own weight for beam A'. a. .- b. /-. d. %.5! c. 7.10
SIT!ATION 4
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REMOVAL EXAM
TIMBER DESIGN
#he hoisting arrangement for lifting a large pipe is shown in the figure TD-RE005. #he spreader is a timber section with /** mm ) /** mm dimension. Its length is 5.* m" allowable compressive stress of +,a and its modulus of elasticity is ? <,a. 8hat is the ma)imum weight of pipe" in $N" that can be lifted based on the following conditionsB 2Assume pinned conditions at the ends of the spreader.3 %se: 3 &* Problem 1" Problem 11 Problem 12
If the spreader is considered to be a short column. b. %!.** a. 90.00
c. *.**
d. 55.55
If the spreader is considered to be a intermediate column. a. 55.55 b. .% c. 22.57
d. /?.?/
'ased upon the allowable stress of the spreader. spreader. a. 55.55 b. 40.00
d. *.**
c. .!%
SIT!ATION 5
A vertical .*$N load is applied as shown on a wooden post of rectangular cross section see figure %se: b = ?* mm h = /* mm a = 5! mm + = = .* $N (alculate the stress at point '" in +,a. Problem 13 a. >. c. .*5 b. -1.72 Problem 14 Problem 15
(alculate the stress at point (" in +,a. a. >.0 b. +2.03
c. >/.*-
TD-RE006.
d. >/.*d. >*.0%
If the applied force is located at the center determine the stress at D" in +,a. a. *.%? c. *.0% d. /.*b. -0.63
SIT!ATION 6
rom the given truss shown in figure TD-RE007" it is made up of
(ompute the minimum length " " in mm. a. //5.0 b. /?/.-/
c. ?0.*-
d. 142.05
(ompute the minimum length -" -" in mm. a. 5/.! b. !./!
c. 15.63
d. /.%
(ompute the a)ial stress of member '(" in +,a. a. /.55 b. .%
c. 1.33
d. /.*%
SIT!ATION 7
A floor is supported by /** mm ) ** mm wooden Coists spaced at ** mm on centers with an effective span of ! m. #he total floor load transmitted to the Coists is $,a. 8eight of wood of %.! $N;m 5" w = /"*** +,a. Problem 1 Problem 2" Problem 21
Determine the ma)imum shearing stress" in +,a. a. *.0! b. *.0%
c. *.?
d. 0.70
Determine the ma)imum bending stress" in +,a. a. //.! b. /.??
c. 17.58
d. //.%
Determine the ma)imum deflection of the Coist" in mm. a. %.5 c. 5. b. 38.15
d. /.*0
SIT!ATION 8
1efer 1efer to figure figure TD-RE008. A /!* /!* mm 5** 5** mm rectangular
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REMOVAL EXAM
TIMBER DESIGN
$!!owab!e stresses: stresses: 'end 'endin ing g and and tens tensio ion n para parall llel el to the the gra grain in = /.? /.? +,a +,a (omp (ompre ress ssio ion n para parall llel el to the the grai grain n = /5. /5. +,a +,a Shear parallel to the grain = .0* +,a (ompression perpendicular to the grain = 0. +,a +odulus of elasticity = ?.0% <,a Problem 22
Determine the allowable bending stress in the beam" in + ,a. a. /.%% b. /.5 c. 19.98
d. /.?*
Problem 23
(alculate the ma)imum load G8H" without e)ceeding the allowable bending stress" in $N. a. /-. c. !.- d. /-.-% b. 17.98
Problem 24
(ompute the ma)imum load G8H" without e)ceeding the allowable shearing stress" in $N. a. 5%.!* b. /?.** d. 5.** c. 72.00
Problem 25
#he s@uare timber is used as a railroad tie as shown in figure TD-RE004. It carries two uniformly distributed loads of -* $N each. #he reaction from the ground is distributed uniformly over the length of the tie. Determine the smallest allowable dimension b" in mm" if the wor$ing stress in shear is /.* +,a. Fse: a = *.! m b = *. m c = /.* m a. ** b. 50* c. 240 d. *
Steel beam
F
A Wood beam
t Cable
t
Wood beam
Steel beam
V
V
H
H
h A
d
B
Spreader
Cable
Pipe
B
Top view
Side view
Fig. TD-RE005 D
Fig. TD-RE001 P
Cable z
a
B
A
C
D a
C
A y
B
b
x W
b h Fig. TD- RE006
Fig. TD-RE008
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REMOVAL EXAM
TIMBER DESIGN
'()**
p)(,i*
L
(a+e(
L
'()** RF FRA!"#$ PLA#
w TR%&& DETA"L Fig)(e TD-RE00
a
b
b
a b b
Fig. TD-RE00/
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REMOVAL EXAM
TIMBER DESIGN W
B
A
H
C
L Fig. TD-RE001 P y
t B
A
b
α x
b
α
L C H
Fig. TD- RE002
x
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