ME6503 Design of Machine Elements
Third year, Department of Mechanical Engineering
First and second Units Questions.

Answer ALL Questions    PART A – (10 x 2 = 20 Marks)
1)What are the various phases of design process.
 2) Write  down different factors influencing machine design
 3) Define torsional stress
4) Differentiate between impact and shock loading                                                           
 5) What is mean by eccentric loading
 6) Describe material properties hardness, stiffness and resilience.                                           
 7) Define stress concentration factor 
8) Compare straight beam and curved beam.
9.Define bending stress.
10.Define fit and its types.
PART – B( 5×13=65 Marks)     Answer all questions
1.A mild steel bracket as shown in the figure.It is subjected to a pull of 6000N acting at 45 to its horizontal axis.The bracket has a rectangular section whose depth is twice the thickness.Find the cross sectional dimensions of the bracket,if the permissible stress in the material of the bracket is limited to 60 MPa.                                 (16)

2)            A Cantilever of span 500 mm carries a vertical downward load of 6 KN at free end. Assume yield value of 350 Mpa and factor of safety of 3. Find the economical section for the cantilever among a) Circular cross section of diameter  “d”b) Rectangular section of depth “h” and width “t” with h/t =2.   c) I section of depth 7t and flange width 5t where t is thickness. Specify the dimension and cross sectional area .                                      (16)
3.C-clamp is to bear  the force F applied onto it. It has T-section shown in figure .If the maximum tensile stress in the clamp is limited to 130 Mpa.Find ‘ F’    (16)

4) A crane hook has a section shown in figure which for the purpose of analysis is considered tapezoidal shown in figure.It is made of the plain carbon steel with an yield strength of 380Mpa in Tension.Determine the load capacity of thehook for a factor of safety of 3


5) i) A simply supported shaft 30 mm diameter and 200mm long is acted upon by a sudden load of 1000 N at its mid span.this load falls freely from a height of 2mm. find the impact strees produced in the shaft.Assume young’s modulus of the shaft material as 2´105Mpa. (8)
ii)A cantilever of a span 250 mm and 50mm diameter carries a vertical downward load of 3 kN at free end along with a torque of 1000N-m and an axial pull of 15kN.calculate the maximum normal stress at the top and bottom face of the fixed end.(8)