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- Structural Dynamics - SD
- 2018
- PYQ
**Biju Patnaik University of Technology BPUT - BPUT**- Civil Engineering
- B.Tech
**819 Views**- 15 Offline Downloads
- Uploaded 11 months ago

Registration No : Total Number of Pages : 02 B.Tech. PCI6J004 6th Semester Regular Examination 2017-18 STRUCTURAL DYNAMICS BRANCH : CIVIL Time : 3 Hours Max Marks : 100 Q.CODE : C422 Answer Part-A which is compulsory and any four from Part-B. The figures in the right hand margin indicate marks. Part – A (Answer all the questions) Answer the following questions : multiple type or dash fill up type : Q1 a) b) c) d) e) f) g) If the natural frequency of a system matches with the forcing frequency, the phenomenon is known as ……… Resistance to the motion of a vibrating body is known as …… Odisha state comes under zone ….. of earthquake as per new code provisions. The structures that experience vibrations are ….. structures. For describing equation of motion of any vibrating system, three forces i.e. (i)……….,(ii) ……., and (iii)……. are required, in general. The instrument generally used to measure the acceleration of a vibrating body is ………. The systems having one of their natural frequencies equal to zero are known as ……… systems. h) Magnitude of earthquake is usually measured in ………. Scale? i) j) Damping of concrete is ……%. Amplitude of vibration is measured in ……. Units. Q2 (2 x 10) Answer the following questions : Short answer type : a) What Do you mean by natural frequency of a system? b) c) d) Define degree of freedom of a structure. e) f) g) h) What is ‘epicenter’? State the essential difference between free and forced vibrations. Give one example of over damped system. Differentiate between continuous and discrete systems. i) What do you mean by ‘response’ of a system? j) State different sources of excitation. Differentiate between magnitude and intensity of earthquakes. What is impulsive force? (2 x 10)

Part – B (Answer any four questions) Q3 Q4 a) Determine the time response of the undamped spring-mass system to the pulse force as shown in figure. (10) b) What is logarithmic decrement? (5) a) Damped vibration of a spring-mass-dashpot system gives the following information. Amplitude of 2nd cycle = 1.3 cm. Amplitude of 3rd cycle = 1.1 cm. Spring constant, k = 7 Kg/cm. mass, m=3 kg. Determine the damping constant, assuming it to be viscous. What do you mean by modal analysis? (10) A spring mass system k1, m1 has a natural frequency f1. Calculate the value of k2, which when connected to k1 in parallel, increases the frequency by 40%. What do you mean by coordinate coupling? (10) b) Q5 a) b) (5) (5) Q6 a) b) Derive the equation for longitudinal vibration of rods. Show with the help of figures, how you can calculate the equivalent stiffness of springs in series and in parallel. (10) (5) Q7 a) Differentiate between ‘accelerometer’ and ‘vibrometer’. (10) b) What do you mean by free damped vibration? Write the equation of motion for it and explain the terms. (5) a) Consider the system shown in figure below and obtain the natural modes of vibration. Take ‘k’ = 30 units and ‘m’ = 30 units. (10) b) Differentiate between underdamped, over damped and critically damped systems. (5) a) A vibrating system is defined by the following parameters, m = 4 kg, k = 120 N/m, c = 4 N-s/m. Determine damping factor, damped frequency, logarithmic decrement and the ratio between two successive amplitudes. (10) b) Differentiate between Coulomb damping and Structural damping. (5) Q8 Q9

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