Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 8th Semester (Eight Semester) 2016-17 NCE054 Machine Foundation Design Question Paper
B.TECH.
THEORY EXAMINATION (SEM?VIII) 2016-17
MACHINE FOUNDATION DESIGN
Time : 3 Hours Max. Marks : 100
Note : Be precise in your answer. In case Ofnumerical problem assume data wherever not provided.
SECTION ? A
1. Explain the following: 10 X 2 = 20
(a) What is meant by Logarithmic decrement?
(b) Define Damping ratio?
(c) Mention the types of machine foundation?
((1) Explain about hammer foundation?
(e) List the field methods used to determine the dynamic properties of soil?
(1') What is coefficient of elastic uniform compression?
(g) Give the importance of Vibration isolation in case of machine foundations ?
(h) List the various isolation materials ?
(i) Write a note on rotary type machines ?
(j) N me the commonly used Vibration absorbers ?
SECTION ? B
2. Attempt any five of the following questions: 5 x 10 = 50
(a) Derive general equation of motion for an undamped free Vibration of a single degree of
freedom system.
(b) Find the response of an SDOF system subjected to Harmonic excitation in the form of a
Sine wave. A weight of 13.8 N is vertically suspended on a steel wire of length 125 cm
and cross sectional area 6. 5 x 10'3cm2. Determine the frequency of free vibrations of
the weight. If modulus of elasticity of steel is 2.12 X 105 N/mmz. Determine the
amplitude of this, Vibration if the initial displacement is 0.025 cm and initial velocity is
2.50 cm/sec.
(c) How will you determine the natural frequencies of the machine foundation by using
Ford and Haddow's method ?
(d) The coefficient of elastic uniform compression of a soil is found to be 24000kN/m3
using a plate of diameter 4m. What would be percentage variation in itsvalue if the
diameter of the plate is halved?
(e) The following data refers to a block Vibration test. Obtain the value of coefficient of
uniform elastic compression of the soil. Estimate the spring constant of the system.
Weight of machine = 22.50 kN, weight of oscillator = 300 N and size of foundation
block is 2.50 m x 3.00 m X 2.00 m height. Determine the value of damping ratio
ardmanimum amplitude. What is the prospect of resonance, if the operating frequency
of the oscillator is 600 rpm ?
Frequency of 30 36 40 46 49 53 55 58
Vibration(Hz)
Amplitude (mm) 0.065 0.095 0.150 0.380 0.430 0.375 0.320 0.270
(1') What do you understand by the term Vibration isolation? Discuss active and passive
isolation methods of Vibration ?
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(g) What are the pr0pertiewmm?9?a?ht??ewpla?on W?mwa?emibe
the properties of any two Vibration isolating materials.
(h) Outline the construction guidelines for providing Vibration absorbers?
SECTION ? C
Attempt any two of the following questions: 2 x 15 = 30
3. (3) Starting from fundamentals, derive the expression for natural frequency of SDOF
system of free Vibration subjected to damping.
(b) A Foundation block of weight 30 kN rest on a soil for which the stiffness may be
assumed as 25000 kN/m. The machine is vibrated vertically by an exciting force of 3.0
sin (30t) kN. Find the natural frequency, natural period, natural circular frequency and
the amplitude of vertical displacement. The damping factor is assumed to be 0.50.
4. (a) What are seismic wave propagation tests? Explain how the shear modulus is estimated
by seismic cross?hole technique?
(b) Discuss on the Vibration isolation techniques for rigid foundation?
5. Summarize the principles of design of foundation for impact type machine with suitable
Illustrations?
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This post was last modified on 30 January 2020