CIVE 310 Exam 1, Fall 2004

CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 1 QUIZ 1 Fall 2004-2005 (Wednesday, November 10, 2004) CIVE310 - MECHANICS OF MATERIALS CLOSED BOOK, 1 ½ HOURS Name: ID#: NOTES • 2 PROBLEMS – 12 PAGES. • ALL YOUR ANSWERS SHOULD BE PROVIDED ON THE QUESTION SHEETS. • TWO EXTRA SHEETS ARE PROVIDED AT THE END. • ASK FOR ADDITIONAL SHEETS IF YOU NEED MORE SPACE. • SOME ANSWERS MAY REQUIRE MUCH LESS THAN THE SPACE PROVIDED. • DO NOT USE THE BACK OF THE SHEETS FOR ANSWERS. • DRAFT BOOKLET WILL BE PROVIDED; BUT DO NOT USE FOR ANSWERS. • BOTH QUESTION SHEETS AND DRAFT BOOKLET SHOULD BE RETURNED. • CHECK BOXES ARE FOR YOU TO CONFIRM THAT HAVE SOLVED A QUESTION YOUR COMMENT(S) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ DO NOT WRITE IN THE SPACE BELOW MY COMMENT(S) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ YOUR GRADE Problem I: _ _ _ /75 Problem II: _ _ _ /25 Other: _ _ _ __________________ TOTAL: /100 CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 2 Problem I: (75 points) The circular steel tube shown in Figure I has the following properties and dimensions: • E = 200 x 106 kPa (kN/m2) : Modulus of elasticity • γ = 80 kN/m3 : Weight density (about 8 times water) • σy = 255,000 kPa : Yield strength in tension and compression • FS = 1.5 : Factor of safety • L1 = 1.2 m L2 = 0.8 m • D1 = 0.05 m D2 = 0.03 m D2 C P B A Figure I D2 D1 L1 L2 CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 3 1. IGNORE OWN WEIGHT and let P = 120 kN Solve for the problem as follows: • Draw Axial Force, Stress, Strain, and Displacement Diagrams. (20 points) • Discuss safety (brief). (5 points) • Compute the stiffness of the system. (5 points) Calculations and/or Diagrams: CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 4 Calculations and/or Diagrams (cont’d): CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 5 2. AGAIN IGNORING THE OWN WEIGHT with P = 120 kN and referring to question 1. In order to achieve the most economical and safe solution for optimum design, determine the minimum thickness “t” required for segment AB by varying the outer diameter D1 while keeping the inner diameter D2 = 0.03 m. (15 points) Calculations and/or Diagrams: CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 6 Calculations and/or Diagrams (cont’d): CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 7 3. CONSIDERING OWN WEIGHT ONLY with P = 0, and referring to the original properties and dimensions as in question 1. • Compute the maximum stress and its location, and comment on safety. (15 points) • Compute the top displacement at C and the stiffness of the system. (15 points) Calculations and/or Diagrams: CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 8 Calculations and/or Diagrams (cont’d): CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 9 Problem II: (25 points) Referring to the beam-bar system shown in Figure II, the concentrated downward vertical force P is a moving load, and can assume any position on the beam between A and D. Ignore the own weights of the beam and bar. Determine the positions of the load P and compute the corresponding force in Bar CE, for the following cases: • Maximum Tension in Bar CE. • Maximum Compression in Bar CE. • Force in Bar CE is equal to P in tension. Note: You should compute one position and corresponding force for each of the cases above. Calculations and/or Diagrams: P L/2 L/2 Bar CE C B A L D E Beam ABCD Figure II CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 10 Calculations and/or Diagrams (cont’d): CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 11 EXTRA SHEET: Continued from page _______ Name: ID#: Calculations and/or Diagrams: CIVE310 - Fall 2004-2005 Quiz 1 H. Basha &M. Mabsout 12 EXTRA SHEET: Continued from page _______ Name: ID#: Calculations and/or Diagrams: