South Valley University Mechanical Vibrations Faculty of Engineering Code: ENM 314

Dept. of Mechanical Engineering 2013/2014

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Question One: 1. Describe briefly areas of study in vibration 2. Indicate the importance of study of vibration 3. Give various classifications of vibration 4. State the steps involved in vibration analysis 5. Mention the main sources of vibration 6. What are the most common machinery problems that cause vibration 7. Sketch the procedure of vibration analysis 8. Give three examples each of the bad and the good effects of vibration. 9. What are the three elementary parts of a vibrating system? 10. Define the number of degrees of freedom of a vibrating system. 11. What is the difference between a discrete and a continuous system? Is it possible to

solve any vibration problem as a discrete one?

Question Two:

1. Figure shows a motorcycle with a rider. Develop a sequence of three mathematical models of the system for

investigating vibration in the vertical direction. Consider

the elasticity of the tires, elasticity and damping of the

struts (in the vertical direction), masses of the wheels, and

elasticity, damping, and mass of the rider.

2. A study of the response of a human body subjected to vibration/shock is important in many applications. In a standing posture, the masses of

head, upper torso, hips, and legs and the elasticity/ damping of neck, spinal column,

abdomen, and legs influence the response characteristics. Develop a sequence of three

improved approximations for modeling the human body.

3. Figure shows a human body and a restraint system at the time of an automobile collision. Suggest a simple

mathematical model by considering the elasticity, mass,

and damping of the seat, human body, and restraints for

a vibration analysis of the system.

With my best wishes Dr. Nouby M. Ghazaly