IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1 MOMENT-MAGNIFIER OF 1.05.

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1 Name: Cack Zoleman CE311 FINAL EXAM Tuesday, December 12, 2017, 8am to Noon, Room 200 You may use the Steel Manual, Calculator, Drawing Supplies, only 100 points Given Steel Properties: E = ksi, G = ksi; A36 Steel (F y =36 ksi, F u =58 ksi); A992 Steel (F y =50 ksi, F u =65 ksi) Strength of Materials Formulae: Stress = E = G Bending Flexural (normal) Stress M/EI = 1/ = -y/ =My/I M=EI I = ( /4)r 4 for a solid circular cross-section Beam Shear Stress = VQ/It q = VQ/I q = F/s I = ( /4)r 4 for a solid, circular shape of radius r Torsional Formulae - J J Formulae for a Closed Rectangle Reinforced Concrete: (psi) 1 depends on the strength of the concrete, as follows: If f c < 4 ksi, 1 = 0.85 If f c > 8 ksi, 1 = 0.65 If f c is between 4 and 8 ksi, then 1 = (8-f c) (units are ksi) 0.85 If b/t>10 J Formula for Open Sections, Composed of Thin Plates 1 3 J bt 3 Where b is the length of the long dimension of each plate and t is the thickness. Truss Degree of Indeterminacy: DOI = b + r 2j b = number of bars r = no. of reaction components j = number of joints IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1 MOMENT-MAGNIFIER OF Page 1 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

2 Live Load Reduction Factor: ASD Load Combinations: LRFD Load Combinations: THEORETICAL K-VALUES. Table C-A-7.1 Approximate Values of Effective Length ABBREVIATIONS psf pounds per square foot plf pounds per linear foot k kip (kilo-pound) DOI Degree of Indeterminacy Page 2 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

3 Bonus Questions (0.1 points each) FILL IN THE BLANK 1. T Variusness 2. Tyroil 3. D Squarius 4. Tacktheratrix 5. Probincrux III 6. Javaris Jamar 7. Davoin 8. Hingle 9. L Carpetron 10. Margoone 11. Saggitariutt 12. Hardunkichud 13. Swirvithan 14. Zoleman More Bonus Questions (0.1 points each): 15. Who was the only person to defeat Dan Gable in college? 16. Is the Principle of Virtual Work more like bacon or is it more like scrapple (credit not given without justification. Use the back of this page, if necessary)? 17. What is the current name of the city that was formerly known as Constantinople? 18. What city is home to the Joe Louis Arena? 19. What country suffered the two deadliest earthquakes in history, killing 830,000 in 1556 and 750,000 in 1976? 20. Who famously said that life's three important things were "family, religion and the Green Bay Packers"? 21. Who was the first US President to resign while in office? 22. What is the unit weight of steel, in units of lbs per cubic foot? 23. How many gallons of beer are contained in a standard US beer barrel? 24. What African-American athlete won 4 gold medals at the 1936 Berlin Olympic Games, famously snubbing Adolf Hitler s attempt to showcase the resurgent Nazi Germany and its ideals? Page 3 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

4 1. (2 points). Two views of a beam-column connection are shown. The connection consists of a 3/8 -thick shear tab (plate) that is shop-welded to the column flange and field-bolted to the web of the beam with (4) ¾ bolts. The connection is: y Column Beam x x Shear Tab welded To column y A. Moment-resisting about the x and y axes. B. Pinned about the x and y axes. C. Moment-resisting about the x axis, but pinned about the y axis D. Moment-resisting about the y axis, but pinned about the x axis. 2. (2 points). TRUE or FALSE. The building below is stable. Given: (2) pin-ended braces one along column line 1 and one along column line 4. All foundations are pins. All beam-column connections are pins. The roof consists of metal decking that is welded to the tops of the beams, such that it forms a structural diaphragm. Page 4 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

5 3. (2 points). The building plan shown has a Code Specified live load pressure of 100 psf for all occupied floors. There are 3 occupied floors. Among the following, which member would have to be designed for the largest live load pressure, after considering the live load reduction factor? A a). Column A1 at the foundation 50 b). Column A2 at the foundation B c). Column B2 at the foundation 50 d). A typical fill beam for this floor C 4. (2 points). For which condition is the theoretical effective length factor K smallest in the vertical columns? W16x26 W40x (A) 30 (B) W16x26 W16x26 30 (C) 30 (D) 5. (2 points) What is the theoretical K-value for the columns in the frame shown if the beam is infinitely stiff in flexure (i.e., EI is infinite)? Given: Ideal frictionless pin foundations, simple (pinned) beam-column connections. Beam EI is infinite Answer K = Page 5 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

6 6. (2 points). Determine the DOI for the Truss if all of the member-to-member connections are RIGID. DOI: 7. (2 points) Given the pin-connected truss and assuming that self-weight is ignored, identify which members are axialonly (P), bending-only (M), and combined bending-axial (PM). H G w = distributed loading F True Pin-Connected Truss A B C D E Axial-Only (P) Members are (list): P P P = concentrated load Bending-Only (M) Members are (list): Combined Bending-Axial (PM) Members are (list): Page 6 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

7 8. (10 Points) Select the lightest possible A992 W-shape as a typical interior fill beam for the floor below, considering bending moment, only (assume the beam is adequate for shear and deflection). Given: The simply-supported, equally-spaced fill beams continuously support a 5 thick concrete slab (concrete unit weight= 150 lb/ft 3 ) that is supported by corrugated steel decking that is welded to the compression flanges of all beams. Dead Load = slab weight, beam self-weight Live Load = 75 psf (after the application of the Live Load Reduction Factor, per code). A B C D Interior Fill Beam Typical Floor Framing Plan Answer: W x Page 7 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

8 9. (11 points). Plot the moment diagram for Beam ABC. A is a pinned foundation. C is a roller foundation. Nylon rope BD is pin-ended, providing support of the beam at B. Given: Beam ABC: E = 10000ksi, I = 10 in 4, A = 2 in 2 Nylon Rope BD: E = 300ksi, I = 0 in 4, A = 0.1 in 2 Materials remain elastic. Failure is not a consideration Nylon Rope D 0.1 kips/inch 60 inches A B C 100 inches 100 inches Page 8 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

9 10. (10 points). Determine the allowable ASD load P n / for the 12-ft-long pin-ended A36 S8x23 column. P n / Pn/ P n / Strong- Axis View P n / Weak-Axis View Answer: P n / = kips Page 9 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

10 11. (10 points). Select the lightest W14 A992 column shape that is adequate per ASD for grid location A2 in the industrial building, below, if the column is considered to have an applied load of 200 kips (ignore column selfweight). Assume that there is no connection eccentricity, so that the column is purely axially-loaded. Foundations are pinned. All connections are pins. It is a single-story building with a story height of 24-ft. The roof acts as a structural diaphragm. Column lines 1 and 3 contain full-story X-bracing, as shown. Column line 2 contains no bracing. Bracing along column lines A and B brace the columns at their tops and at midheight, as shown Elevation Col. Lines 1 & 3 Close-Up View of Column 3D View of 1-Story Building 24, typ Elevation Col. Lines A & B Answer: W14 x Page 10 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

11 12. (8 points) Using ACI (American Concrete Institute) methods, determine M n for the reinforced concrete T-beam cross-section, shown, which contains 4 No. 8 tension bars (f y = psi) and uses concrete with a compressive strength f c =3000psi. The beam is subjected to positive bending (tension on the bottom) #8 Bars 16 CROSS-SECTION ANSWER: n = kip-ft Page 11 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

12 13. (10 points). The parabolic arch shown is subjected to a distributed load of 1 kip/ft, while composed of stones with a 10 x10 cross-section. This traditional masonry arch is considered to have infinite compressive strength, but zero tensile strength. Determine: a. The maximum normal stress in the arch. b. The angle the arch makes with respect to the horizontal, at Point A. w = 1 kip/ft B 10 A Solid Rock Foundation 40 C Solid Rock Foundation ANSWERS: max = ksi A = degrees Page 12 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

13 14. (15 points). The A992 W10x68 member is subjected to an ASD centerpoint load of 25kips such that the load has both vertical and lateral components (refer to the slope shown on the cross-section), while laterally braced at its ends, only. In addition, it is subjected to an axial force of 50 kips. Determine the ASD interaction ratio to assess the member adequacy. Ignore self-weight. ` 25 kips 50 kips 50 kips 25 kips ANSWER: Interaction Ratio = Safe per ASD? Yes or No Page 13 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1

14 15. (12 points). Determine the vertical movement of point C, due to the applied horizontal, uniformly-distributed loading, w=0.1 kip/in, between A and B. Given: EI = 1,000,000 kip-in 2 w = 0.1 kip/in B C 100 A 50 ANSWER: Vertical Deflection at C = inches Page 14 IF SECOND-ORDER EFFECTS NEED TO BE CONSIDERED ON THIS EXAM, ASSUME A B1