2017 Exam 1 Study Guide - Lafayette College 2017 Exam 1 Study Guide Kurtz 21. (5 points) Determine...

CE311 2017 Exam 1 Study Guide Kurtz

CE311 EXAM 1 STUDY GUIDE Exam 1 Date: Thursday, September 21st, 2017, 7 to 9:30pm

This Guide Last Updated on August 21st, 2017

Study Guide This study guide compliments the Past Exam Problems. Students should study both. Answers at the end.

Given Formulae: Law of Cosines:

Law of Sines:

Stress = E = G

Bending Flexural (normal) Stress

M/EI = 1/ = -y/ =My/I M=EI I = (/4)r4 for a solid circular cross-section

Beam Shear Stress = VQ/It q = VQ/I q = F/s I = (/4)r4 for a solid, circular shape of radius r

Also: = PL/AE

A B

C

b

c

a


Exam Format Exam designed for 2 hours. 2.5 hour time limit. You will be allowed to use your steel manual, a calculator, and pencils. Some questions will be purely conceptual in nature, while others will be computational. Approximately 30% of the exam will be multiple choice, short answer, true/false, etc and these will often be conceptual in nature, while approximately 70% will be fully worked problems.

Recommended Problems From the Segui Textbook:

Chapter 2: 2.3, 2.5 Chapter 4: 4.3-1, 4.3-3, 4.7-1, 4.7-3 Note: Segui covers the use of the “Stiffness Reduction Factor”, but CE311 will not cover this.

Coverage Lesson Objectives from Lessons 1 to 9 and Lab 1. You are expected to be able to do Strength of Materials problems involving direct normal stresses, direct shear stresses, bending normal stresses, beam shear stresses, and the combination of axial and bending effects.

Define strength and serviceability limit states. 1. (1 point) Situation: a structural engineering firm was sued because a building it designed shook so excessively in high

winds that the exterior glass fell out, landing in the street. Is this an example of a strength limit state or a serviceability limit state, exceeded?

2. (1 point) Situation: a hospital sued a structural engineering firm because excessive vibrations in the building were inappropriate for an operating room. Is this an example of a strength limit state or a serviceability limit state, exceeded?

3. (1 point) Situation: a structural engineering firm was sued because an agricultural building roof it designed collapsed under a record snow loading (more than the region had ever experienced), killing 16 hogs. Is this an example of a strength limit state or a serviceability limit state, exceeded?

4. (1 point) TRUE or FALSE. A strength limit state is only considered to have been reached if any parts of the structure (e.g., beams, columns, connections, braces, etc.) fracture.

5. (1 point) TRUE or FALSE. A buckled column is considered an example of a Serviceability Limit State.

Distinguish between strength limit states of material failure and instability. 6. (2 points) Using sketches and descriptions, distinguish between strength limit states of material failure and instability.

Distinguish between member instability (member buckling) and overall structural instability

7. (1 point) TRUE or FALSE. If the loads P were increased until failure occurred, the structure below would fail because the entire structure is unstable.

Define Structural Analysis and Steel Design.

8. (1 point) TRUE OR FALSE. Structural Analysis is the selection of structural members that have adequate strength and stiffness.

Define Normal and Shear stress, list example occurrences, and state the applicable formulae. 9. (1 point) TRUE or FALSE. The maximum normal stress on this beam is equal to P/A. Given: The beam shown has a cross-sectional area of A.

Indicates pin (or moment-release)

Indicates rigid (or moment-resisting) connection.

P P P P


10. (1 point) TRUE or FALSE. For previous beam, the maximum normal stress on this beam is equal to P/I. 11. (1 point) TRUE or FALSE. For previous beam, the maximum normal stress on this beam is equal to Mc/I, where

M=(P/2)(L/2), c = h/2, and I is given.

12. (1 point) True or False. For the previous beam, the average shear stress at the left support is equal to P/(2A). 13. (10 points) Determine the required pin diameter for the pin at point A if it is subjected to double shear and has an

allowable shear stress allow = 6 ksi.

Compute internal normal force P, bending moment M, and shear force V, normal stress , and shear stress in determinate structures by cutting and applying equilibrium.

14. (10 points). The beam below has a 6”x 6” cross-section. Determine maximum compressive stress due to bending occurring anywhere in the beam and specify the location at which this occurs. Given: Point A is supported by a pin, while Point B is a roller support.

15. (10 points). For the previous beam, determine the maximum magnitude of shearing stress that occurs anywhere in the

beam and specify the location at which this occurs.

16. (1 point). TRUE or FALSE. For the previous beam, the internal moment at point A places compression on the top-side of the beam.

17. (10 points). Determine the internal forces and moments at Point B. Given: The beam has a fixed support at Point A and is free at Point C.

P

Cross-Section

Area A Moment of Inertia I

L/2 L/2

h

5 ft 5 ft12 ft

1 kip/ft5 kips 5 kips

A B


18. (1 points). TRUE or FALSE. For the previous beam, the internal moment at point B places compression on the top-side

of the beam. 19. (10 points) Determine the magnitude of the internal axial force at point F, specifying either compression or tension as

well as the magnitude of the internal moment M at point F, specifying whether the moment causes compression on the top or the bottom of the member. Given: Member ABFC is a continuous member that is connected to member CDE by a pin at C. There are pinned supports at A and E. There is a uniformly-distributed loading of 1 kip/ft from B to C and a uniformly-distributed loading of 2 kips/ft from C to D.

20. (5 points) The steel I-beam (E=29000 ksi) below is made from three 8”x1” plates, resulting in a total depth of 10” and a

moment of inertia I = 368 in4. If the bending stress at the top of the flange is 2.9 ksi, determine the strain at the top of the web (point “a”).

5 ft 10 ft

A

B C

D

E

10 ft

1 kip/ft 2 kip/ft

F

5 ft

8”x 1” Flange

8”x 1” Web

I-BEAM

CROSS-SECTION

SIDE VIEW

OF BENT

I-BEAM

8”x 1” Flange

“a”


21. (5 points) Determine the internal moment on the section of 10”x10” wooden beam below if the internal normal stress distribution that is shown can be resolved into two internal resultant forces R = 1 kip each.

22. (20 points) Determine the resultant horizontal normal force on the flange of the Tee beam at section 1-1, located 2 feet to the right of the left support, as shown. Given: The Tee-beam is built from an 8”x1” flange and an 8”x1” web. It is subjected to a 1 kip/ft uniformly distributed load over its 10 foot simple span.

23. (10 points) Determine the normal stress, due to flexure, at point C. Given: the beam is simply-supported by a pin-support at A and a roller support at B. The beam is center-point-loaded by a 100-kip load, as shown. The cross-section is 6”x12”, as shown.

Compute the moment of inertia of a composite section (such as an I-shape).

(with other objectives) Compute the extreme fiber stress for a member subjected to combined bending and axial effects.

24. (12 points) Determine the required dimension b of the beam cross section if the allowable bending stress allow = 1.40 ksi and the distributed load w =200 lb/ft.

Given: Assume the support at A acts as a pin and that the support at B can be treated as a roller.

8”x 1” Web

TEE-BEAM

CROSS-SECTION

8”x 1” Flange

SIDE VIEW OF TEE BEAM

10 ft.

w = 1 kip/ft

1

1

2 ft.

50 inches 50 inches A

B

C

Side View of Beam

100 kips

Beam Cross Section

6 in.

12 in. 10 in. 5 in.

M = ?

R = 1kip 10 in.

R = 1kip

10 in.

SIDE VIEW OF BENT BEAM CROSS-SECTION OF WOODEN

BEAM


25. (17 points) Determine the magnitude of normal stress on the top of the beam at point F and specify whether the stress is

compressive or tensile.

Given: All members have a cross-section that is a 6”x6” solid. Member ABFC is a continuous member that is connected to member CDE by a pin at C. There are pinned supports at A and E. There is a uniformly-distributed loading of 1 kip/ft from B to C and a uniformly-distributed loading of 2 kips/ft from C to D.

26. (2 points) For the frame below, circle the correct answer:

a. Ax = 0 and the axial force in BC is zero. b. Ax ≠ 0 and the axial force in BC is zero. c. Ax = 0 and the axial force in BC is non-zero. d. Ax ≠ 0 and the axial force in BC is non-zero.

27. (20 points) A building frame is made with rigidly-connected W8x24 steel shapes, oriented as shown below (note the

flange positions). The frame is supported by pinned foundations at points A and E. Positions B and D are rigid connections. There is an internal pin connection at point C. The frame is subjected to a live load of 8 kips at pin C. Determine the maximum compressive stress due to live load at a position that is immediately to the right of Point B and indicate whether this maximum compressive stress occurs on the top or on the bottom side of beam BC.

5 ft 10 ft

A

B C

D

E

10 ft

1 kip/ft 2 kip/ft

F

5 ft

20 ft

1 kip/ft

15 ft

20 ft

A

B CD

EAx Ex

Ey Ay


Construct shear and moment diagrams for beams, using the Strength of Materials sign convention.

28. (7 points) Write the function for the internal shear force V(x) and the internal bending moment M(x) of beam AB due to the concentrated moment at B where the origin for x is at pinned support A, directed toward roller support B. Write these functions in terms of M, L and x.

Given: Concentrated moment M at position B.

29. (15 points) Write the shear function V(x) and the moment function M(x) for the beam shown. It is subjected to a distributed load that increases linearly from 0 at A to 1 kip/ft at B

30. (13 points) Draw the moment diagram for the beam below. Label the magnitude and location of each local maximum moment. Given: Support A is a roller, support C is fixed, position B is an internal pin.

Construct moment diagrams for frames (plotting the diagram on the compression side of the members), computing and labeling min and max points.

31. (15 points) Draw the moment diagram for member BCD, only. Use the usual Strength of Materials Convention of plotting the diagram on the compression side of the members. Report all minimum and maximum values.

A

B C D

E

8 kips

15 ft.

20 ft. 20 ft.

Orientation of W8x24

AB

M

L

x

10 feet

1 kip/ft

x

AB

1.2 kip/ft

2 kips


Compute shear stresses at any position within beams and frames. Illustrate the powerful influences of span length and structural depth on structural stiffness.

32. (5 points). The trussed girder shown was constructed by welding diagonal members to the top and bottom chords such that the distance from the centers of the top and bottom chords is 5”. Under a centerpoint load of P, the given girder was found to deflect 1” at midspan. If the distance from the centers of the two chords was increased to 12”, all other factors staying the same, determine the expected midspan deflection.

Illustrate the powerful influence of unbraced length on column buckling.

33. (3 points). Columns A and B have the same cross-section. Column A is 10’-long, while Column B is 6’-long. If Column A buckles elastically at an applied axial force P=100 kips, at what force does Column B buckle at, assuming it also buckles elastically?

Estimate truss deflections using the moment of inertia of the top and bottom chords, applying beam deflection formulae. Identify real pinned-connection and rigid connections.

34. (2 points) Is the following beam-column connection simple (non-moment-resisting) or rigid (moment resisting) for strong-axis bending?

Given: the wide-flange beam is connected to the column-face with a bolted angle. There is an unconnected space between the beam flange and the face of the column.

20 ft

1 kip/ft

15 ft

20 ft

A

B C D

E

P

P=100 kips

Column A

P=?

Column B

10’

6’


Compute the degree of static indeterminacy (DOI) for 2D frames and beams using fundamental principals (Statics), Compute the degree of static indeterminacy (DOI) for 2D frames and beams using the loop method, and/or Compute the degree of static indeterminacy (DOI) for 2D frames and trusses.

Determine the degree of indeterminacy of the structures below (3 points each) 35. All members pin-ended, as shown.

36.

37.

38.

39.

40.

Answer (Circle A or B)

A. Simple (non-moment-resisting) B. Rigid (moment resisting)

Bolted angle connection


41.

42.

43.

44.

45. Show why the structure below is indeterminate, but unstable.

CE311 2017 Exam 1 Study Guide Kurtz Draw the line diagrams (FBD’s) for a fill beams, girders, columns, and 1’-wide slab strips for a simple (pin-connected) framed building structure, given the dead weights of the structure, Draw moment diagrams from line diagrams, Compute the bending stresses in a beam, given the internal moment and the section properties.

Consider the building below for the following problems. All floors, including the roof consist of 6”

thick concrete slabs (concrete unit weight=150 lb/ft3), uniformly-spaced W16x26 fill beams, W18x35 girders, and W12x45 columns. Girders and fills are in strong-axis bending. Slab-strips are considered simply-supported. A typical floor framing plan and 3D image are shown.

46. (2 points) TRUE or FALSE. All of the interior fill beams on the 2nd floor between column line A and B have the same maximum bending moment.

47. (2 points) TRUE or FALSE. Interior fill beams on the 2nd floor between column line A and B have greater maximum bending moment then interior fill beams on the 3RD floor between column line A and B.

48. (2 points) TRUE or FALSE. The column at grid location A4 resists a greater axial force at the ground than at a position just above the 3rd floor.

49. (10 points) Draw the line diagram for fill beam A (see plan view), determine the maximum shear force, the maximum

bending moment, and the maximum normal stress due to bending.

A B C D

1

2

4

3

20’

25’

30’

25’ 25’ 30’

Roof

Ground

2nd Flr

3rd Flr

1

2

4

3

A

B

C

D

A

B


50. (12 points) Draw the line diagram for point-loaded girder B (see plan view), determine the maximum shear force, the maximum bending moment, and the maximum normal stress due to bending.

51. (12 points) Determine the column force for the column at grid location D4 at the foundation level. 52. (25 points). Problem: Determine whether the column at grid location B3 is adequate using the ASD method, between

the ground and 2nd floor, considering all load combinations. Given: The 12’-long column at grid location B3 is an A992 (Fy=50 ksi) W10x39. The building is a stable simple-braced frame where columns are considered to be pinned at floor levels (bracing and floor diaphragms omitted for clarity). Columns are all 12’-long. Dead Loads 2nd floor dead load : consists of a 4.5” thick concrete slab (unit weight of concrete = 150 pcf), supported by W16x26 fill beams and W18x35 girders. The roof dead load: consists of a built-up roof deck that weighs 14 psf, supported by W14x22 fill beams and W16x36 girders. The column weight should be accounted for. Live and Snow Loads: 2nd floor live load is 80 psf. Live load reduction factor is applicable. Roof snow load is 100 psf (building is located in Northern Manitoba) Roof live load Lr = 20 psf (this accounts for the loads present during roof repair, etc.) No Other Loads (e.g., this column does not participate in the lateral system, so it takes no wind or earthquake)

53. (25 points). Problem: Referring to the previous building, determine whether the column at grid location C4 between

the ground and the 2nd floor is adequate using the LRFD method, considering all load combinations (refer to previous building)

Given: The 12’-long column is an A992 W8x31. The building is a stable simple-braced frame (bracing omitted for clarity). All loads are the same as previous. 54. (15 points) Problem: Referring to the previous building, determine the LRFD moment Mu that the 2nd floor girder on

column line 2, between D and E must be designed for. 55. (15 points). Problem: referring to the previous building, determine the ASD shear force V that the roof fill beam on line

D, between 1 and 2 must be designed for. 56. (12 points) A 20’-long A992 W16x26 shape is embedded in concrete at its base, but is free at its top, supporting a water

tank. What is the maximum load that may be placed in the tank at the top of the column, without actually causing

A

B

C

D

E

1

2

3

4

Ground Flr

2nd Flr

Roof

30’

30’

30’

30’

30’

30’ 30’

CE311 2017 Exam 1 Study Guide Kurtz buckling? Use theoretical K-values.

57. (3 points) True or False. A column with Fy=50ksi and a controlling slenderness ratio KL/r=150 will buckle elastically, when loaded to failure.

58. (3 points) True or False. A column with Fy=50ksi and a controlling slenderness ratio KL/r=50 will buckle elastically, when loaded to failure.

59. (2 points) True or False. The Euler expression is a good predictor (within 15% most of the time) of the column buckling stress when the column is very slender.

60. (2 points). True or False. The ASD method will generally require larger member sizes than the LRFD method, if the applied live loads are very high, relative to the applied dead loads.

61. (2 points). True or False. The ASD and LRFD methods will always result in the same member sizes 62. (2 points) What does LRFD stand for? 63. (2 points) Which design method, LRFD or ASD, uses two different safety factors, accounting for both load uncertainty

and resistance uncertainty? 64. (2 points) What is the standard ASD safety factor for a ductile failure? 65. (2 points) What is the standard ASD safety factor for a brittle failure? 66. (3 points) In LRFD, why is there (typically) a higher load factor for live load than for dead load? 67. (3 points) In LRFD, why is there a higher factor for buckling or yielding than for fracture? 68. (2 points) TRUE or FALSE. The ASD method will always lead to more conservative (larger, safer) member selection

than LRFD. 69. (2 points) TRUE or FALSE. The LRFD method will lead to more conservative (larger) member selection than ASD

when live loads are relatively high and dead loads are relatively low. 70. (3 points) Characterize or describe the kind of event (i.e., give a name to this event) that is represented by the LRFD load

combination U=1.2D + 1.6S + 0.5L 71. (3 points) For the LRFD load combination U=1.2D + 1.6S + 0.5L, explain why the load factor on live load less than 1? 72. (4 points) Fill in the blank, using the words in the box on the right Every ______________ in a structure must be able to sustain all effects (forces, moments, etc.) of each _____________. Each load combination represents a particular kind of __________, which may be critical for some members of the structure, but not all. For example, a ___________ may be most vulnerable to the U=1.2D + 1.6S + 0.5L combo because snow is weighted high. Meanwhile, __________ of the building are more likely to sustain maximum bending due to the U=1.2D + 1.6L + 0.5S combo because __________ loads are weighted heavily.

73. (2 points) TRUE or FALSE. The LRFD design buckling load Pn is larger than the ASD allowable buckling load Pn/Pallow because the LRFD method is less conservative.

74. (2 points) TRUE or FALSE. In both LRFD and ASD, the computation of the nominal column buckling strength Pn is the same procedure with the same result.

75. (2 points) TRUE or FALSE. In both LRFD and ASD, the nominal column buckling strength Pn = FcrA, where Fcr is the buckling stress and A is the cross-sectional area.

76. (2 points) TRUE or FALSE. The ASD method relies on the Euler expression to compute the buckling stress, while the LRFD method relies on two different expressions to compute the buckling stress.

77. (2 points). TRUE or FALSE. The frame shown is considered to be braced because the beams are infinitely stiff and the beam-column connections are rigid.

Tank

20’

Tank

20’

Words roofbeam event dead and live load combination floor beams member


78. (2 points) TRUE or FALSE. K is theoretically always less than or equal to one if the frame is braced. 79. (2 points) TRUE or FALSE. K is always greater than or equal to one if the frame is not braced. 80. (2 points) TRUE or FALSE. For the rigid frame shown below, the K value for the columns is less than one.

81. (2 points) What is the K for the column A in the frame below (all connections are simple):

82. (2 points) TRUE or FALSE. For the previous frame, column B is considered braced, but column A is considered

unbraced. 83. (2 points) TRUE or FALSE. It is possible for a compression member to have rotational restraint at one end, but not at

the other end. 84. (2 points) TRUE or FALSE. In a rigid building frame, columns receive greater rotational restraint when the beams that

they are rigidly connected to have greater flexural stiffness. 85. (2 points) TRUE or FALSE. In a simple-braced building, columns receive greater rotational restraint when the beams

that they are pin-connected to are larger. 86. (2 points) What is the theoretical effective length factor K for Column AB in the frame below? Given: A is a pinned foundation, B is a rigid beam-column connection, C is a pinned connection, D is a pinned foundation. Beam BC is an ordinary beam (neither very large nor very small).

Infinite EI

Infinite EI

A B

A

B C

D

Circle the best answer: A). K = 1 B). 1 ≤ K ≤ 2 C). K ≤ 1 D). K ≥ 1

CE311 2017 Exam 1 Study Guide Kurtz 87. (2 points) Estimate the effective length factor K (circle one answer) for the columns shown, assuming that they are

rigidly connected to a beam of infinite stiffness. There is no bracing present.

a). K = 0 b) 0.5 < K < 1.0 c) K = 1 d) 1.0 < K < 2.0 e) K = 2 f) K > 2

88. (12 points) Determine the ASD allowable load Pn/ if the W-shaped column is an A992 (Fy=50 ksi) W12x40. Given: The column is 18 feet long, but has a mid-height brace that prevents movement along one axis, as shown below.

89. (12 points) Determine the LRFD design strength Pn if the column is an A36 (Fy = 36 ksi) S12x50. Given: The column is 12 feet long, but has 5 equally-spaced intermediate braces that prevent movement along one axis, as shown, above.

90. (18 points) Compute the ASD allowable axial load Pn/ for the column shown. It is made out of Grade 50 (Fy=50 ksi) material; a W12x65 section is strengthened by the addition of ¾” thick plates, as shown. It is fixed on one end and pinned on the other, about both axes. Use the “Recommended design value when ideal conditions are approximated” for the K-value of the pinned-fixed condition.

18’

Pn/ = ? Pn/ = ?

Bra

ces

12’

Pn = ? Pn = ?

Infinitely Stiff Beam

Column Column


91. (18 points) Compute the LRFD design strength Pn for the previous. 92. (22 points) Use ASD to assess the adequacy of the W10x60 column at location C3, between the foundation and the

second floor. Given: All beams, columns, and braces are A992 (Fy=50 ksi). All connections are simple (pinned connections), as are the connections to the foundation. All bays are 40’ and all story heights are 12’. As shown in the isometric, the building is braced with diagonal bracing at the corners of the building. This bracing effectively braces every column in the building, at its top and bottom.

Loads: Roof Loads:

50 psf dead load (includes all roof dead load – slab, beams, etc), 50 psf snow load, 20 psf roof live load 2nd Floor Loads:

100 psf dead load (includes all floor dead load – slab, beams, etc), 100 psf live load. Live load reduction factor is applicable.

40’, typ.

40’, typ.

Plan View – Framing Plan

Brace, typ.

A B C D

1

2

3

4

North

4

3

2

1

North

B

C

D

12’

12’

Isometric View (fill beams omitted, for clarity)

Roof

2nd Flr

Foundation

CE311 2017 Exam 1 Study Guide Kurtz Answers 1. (ANSWER: Serviceability) 2. (ANSWER: Serviceability) 3. (ANSWER: Strength) 4. (ANSWER: False) 5. (ANSWER: False) 6. 7. (ANSWER: False) 8. (ANSWER: False) 9. (ANSWER: False) 10. (ANSWER: False) 11. (ANSWER: True) 12. (ANSWER: True) 13. 14. (ANSWER: 8.33 ksi at supports, bottom fiber) 15. (ANSWER: 0.25 ksi at supports, neutral axis) 16. (ANSWER: False) 17. (ANSWER: V=288 lbs, M = 1152 ft-lb) 18. (ANSWER: False) 19. (ANSWER: P=7.5 kips ©, M= 25 ft-kips, © on bottom) 20. (ANSWER: Strain is 0.00008 in/in) 21. (ANSWER: M=6.67 kip-in) 22. (ANSWER: Resultant on flange is 13.9 kips) 23. (ANSWER: Normal stress is 0.579 ksi) 24. (ANSWER: b=4.02” ) 25. (ANSWER: Max normal stress is 8.125 ksi (tension) ) 26. (ANSWER: d) 27. (ANSWER: Max. compressive stress is 46.8 ksi on bottom) 28. (ANSWER: V(x) = -M/L, M(x) = -Mx/L) 29. (ANSWER: V(x) = 1.66 – 0.05x^2, M(x)=1.66x – 0.0166x^3) 30. (ANSWER: Neg: 46.4 @ C, Pos: 11.1 at 6.93’ left of A. ) 31. 32. (ANSWER: 0.174” ) 33. (ANSWER: 278 kips) 34. (ANSWER: A) 35. (ANSWER: 1) 36. (ANSWER: 0) 37. (ANSWER: 1) 38. (ANSWER: 6) 39. (ANSWER: 0) 40. (ANSWER: 2) 41. (ANSWER: 5) 42. (ANSWER: 22) 43. (ANSWER: 0) 44. (ANSWER: 0) 45. (ANSWER: Put horz force on beam: Sum of forces in x is not zero. ) 46. 47. (ANSWER: FALSE) 48. (ANSWER: TRUE) 49. (ANSWER:V=6.02kips, M=45.1 kip-ft, =14.1 ksi) 50. (ANSWER: V=28.1kips, M=252 kip-ft, =52.5 ksi) 51. (ANSWER:55.8 kips) 52. Column is OK. Controlling applied load is 166.6kips (Combination 4). Allowable load is 234 kips 53. Column is OK. Controlling applied load is 45.5kips (Combination 4). Allowable load is 188 kips 54. Factored Moment Mu=287.7 kip-ft. 55. D+S combination controls. V=13.16 kips 56. Pn=10.49 kips

CE311 2017 Exam 1 Study Guide Kurtz 57. TRUE 58. FALSE 59. TRUE 60. FALSE 61. FALSE 62. Load and Resistance Factor Design 63. LRFD 64. 5/3 65. 2 66. Live load is more variable than dead load 67. Fracture is a higher risk 68. FALSE. It depends on the dead-live ratio 69. TRUE. LRFD fears and respects the variability of live loads 70. Blizzard 71. It is unlikely that the largest live load event coincides with a blizzard. 72. Member, load combination, event, roof beam, floor beams, dead+live 73. FALSE 74. TRUE 75. TRUE 76. FALSE 77. FALSE 78. TRUE 79. TRUE 80. FALSE 81. 1 82. FALSE 83. TRUE 84. TRUE 85. FALSE 86. C 87. E 88. 278 kips 89. 462 kips 90. Using parallel axis theorem, Ix=756in4, Iy=915in4. K=0.8. Pn/=1001 kips 91. 1502 kips 92. Combination 4 controls. Applied load P=353.9 kips. Pn/=421.3 kips. Adequate.

2017 Exam 1 Study Guide - Lafayette College 2017 Exam 1 Study Guide Kurtz 21. (5 points) Determine...

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