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EndsemMay 20232019 patternBE Mech

Dynamics of Machinery SPPU Endsem Question Paper May 2023

All 8 questions from this SPPU endsem paper, as printed. Read them here or open the PDF.

Open the PDFMost repeated Dynamics of Machinery questions
Subject code
402042
Pattern
2019 pattern
Exam
Endsem
Session
May 2023
Max. marks
70
Time
2½ Hours
Semester
VII
Paper code
[6004]-605

Printed for: B.E. (Mechanical)

Instructions to the candidates

  1. Answer Q.1 or Q.2, Q.3 or Q.4, Q.5 or Q.6, Q.7 or Q.8.
  2. Neat diagram must be draw wherever necessary.
  3. Figures to the right side indicate full marks.
  4. Assume suitable data if necessary.

Questions

  1. Q1

    1. a)

      A horizontal spring mass system with coulomb damping has a mass of 5 kg attached to a spring of stiffness 980 N/m. If the coefficient of friction is 0.25, calculate: i) the frequency of free oscillations. ii) the number of cycles corresponding to 50% reduction in amplitude if the initial amplitude is 5cm. iii) time taken to achieve this 50% reduction.

      [8]
    2. b)

      Explain with neat diagram mathematical model of a motor cycle.

      Also asked:May 2024

      [5]
    3. c)

      By using energy method, find the natural frequency of undamped free longitudinal vibrations.

      Also asked:Nov 2022

      [4]

  2. Q2

    1. a)

      Derive an expression for the motion of spring-mass dashpot system in case of: i) over damped system ii) critically damped system iii) under damped system.

      [8]
    2. b)

      A flywheel of mass 10 kg and radius of gyration 0.3 m makes torsional rotations under a torsion spring of stiffness 5 Nm/rad. A viscous damper is fitted and it is found that the amplitude is reduced by a factor 100 over any two successive cycles. Find i) Damping factor ii) Damping coefficient iii) Damped frequency iv) Periodic time oscillation

      [5]
    3. c)

      A mass of 3kg is supported on an isolator having a spring constant of 3000 N/m and viscous damping. If the amplitude of free vibration of the max falls to one half its original value in 2 sec, determine the damping coefficient of the isolator. 2

      [4]

  3. Q3

    1. a)

      Define quality factor and states its significance in frequencies response curve.

      [8]
    2. b)

      A single cylinder vertical petrol engine of total mass 400 kg is mounted upon a steel chassis frame and causes a vertical static deflection of 2.5 mm. The reciprocating parts of the engine have a mass of 5 kg and move through a vertical stroke of 120 mm with SHM. A dashpot provided the damping resistance of which is directly proportional to the velocity and amounts to 20 KN at 1 m/s. If a steady state vibrations has been reached. Determine: i) The amplitude of forced vibrations when the driving shaft of engine rotates at 540 rpm. ii) The maximum dynamic force transmitted to the ground through chassis frame (which behaves as a spring). Through the dashpot and through the chassis frame and dashpot together. iii) The driving shaft speed at which resonance will occur.

      [10]

  4. Q4

    1. a)

      Explain forced vibration with rotating unbalance.

      Also asked:Nov 2025

      [8]
    2. b)

      The static deflection of an automobile on its springs is 100 mm. Find the critical speed when the automobile is travelling on a road, which can be approximated by a sine wave of amplitude 80 mm and a wavelength of 16 m. Assume the damping to be given by (damping ratio 0.05) also determine the amplitude of vibration at 75 km/hr.

      [10]

  5. Q5

    1. a)

      For the system shown in figure, find the natural frequencies of vibration and principal modes of vibration.

      [10]
    2. b)

      Derive the concept of torsionally equivalent shaft and derive the equation for its equivalent length. 3

      Also asked:Nov 2025 ·May 2025 ·Nov 2024 ·May 2024 ·Nov 2023 ·Nov 2022

      [8]

  6. Q6

    1. a)

      This part has equations that don’t show as text. Open the PDF to read it.

      [10]
    2. b)

      How do you find Eigen value and Eigen vector by Matrix method.

      [8]

  7. Q7

    1. a)

      What is vibration isolation? Discuss various methods of vibration isolators.

      [8]
    2. b)

      Write short notes on: Pass-by-noise.

      [5]
    3. c)

      Write short notes on: Noise sources and control of industries.

      Also asked:Nov 2022

      [4]

  8. Q8

    1. a)

      Derive an relation between sound intensity level and sound pressure level.

      Also asked:May 2024

      [8]
    2. b)

      Write short notes on: FFT Spectrum analyzer.

      [5]
    3. c)

      Explain with neat sketch the working of sound level.   

      Also asked:May 2025 ·Nov 2023

      [4]