# Mid Examination

Topics: Elasticity, Mechanics, Young's modulus Pages: 2 (407 words) Published: November 16, 2012
Dept. of Civil Engineering
Midterm Examination-2011
2nd year 2nd semester, Course No: CE 213;
Course Title: Solid Mechanics II Total marks: 30, Time: 1 hours and 30 minutes

Answer any three from the following questions

Q1. (a) Define crippling load. Derive the formula of crippling load for one end fixed and other end hinged column. 5

(b) A compound shaft consisting of a steel segment and an aluminum segment is acted upon by two torques as shown in figure 1. What is the total angle of twist at the free end, if maximum shear stress in the shaft is limited to 83 Mpa for steel and 55 Mpa for aluminum? Assume the modulus of rigidity to be 83x1000 N/mm2 for steel and 28x1000 N/mm2 for aluminum. 5

Q2. (a) What is effective length of a column and slenderness ratio? What are the differences between strut and column? 4

(b) A 50mm by 100mm timber is used as a column with fixed ends. Determine the minimum length at which Euler’s formula can be used if E = 10 Gpa and the proportional limit is 30 Mpa. What central load can be carried with a factor of safety of 2 if the length is 2.5 m? 6

Q3. (a) What are the limitation of Euler’s formula. Prove that hoop stress is twice time greater than longitudinal stress for cylinder. 5

(b) A pipe of internal diameter 150mm & 4mm thickness made of mild steel loading a tensile yield stress at 380 N/mm2. Determine the maximum permissible internal pressure if factor of safety is 4....