Question

(a) Briefly describe the usefulness of the knowledge of Mechanical Vibration in the industries by discussing at least two examples with regards to effects of machinery vibrations and reduction/control.

(b) Briefly explain the following terms: i. Modal analysis ii. Modal parameters

(c) Briefly explain resonance.

(d) Briefly explain how measurement and monitoring of machine vibration can be used for preventive maintenance.

in short pls

Answer 1

A) The study about the mechanical vibrations is very much importance when it comes to the all the industries, Vibration analysis is a measurement tool which isused to identify, predict, and prevent failures in rotating machinery. Implementing the vibration analysis on the machines will also improves the reliability of the machines and lead to better machine efficiency and reduced down time eliminating mechanical or electrical failures. Vibration analysis tools and techniquesare using in all verticals of the industry throughout world wide to identify faults in machinery, plan machinery repairs, and keep machinery functioning for as long as possible without failure.

Example1: Conditional monitoring based analysis on the Motor and FAN and Turbines

Example2: In case of the automobiles we use to do the Vibrational analysis on the engine cross head, Exhaust system to reduce the unwanted vibrations

B) i) Modal Analysis: Modal analysis is defined as the study of the dynamic characteristics of a mechanical structure. The modal analysis we can perform on the structures with the help of the Physical testing and CAE also. In physical testing we do testing with the SHAKER TEST and IMPACT HAMMER test.

B ii) Modal Parameters: While performng the modal analysis the out put resultants are termed as modal parameters, those are MODES, Frequencies and Damping Ratios and Mode Shapes

C) Resonace: Practically speaking RESONANCE is the process where the natural frequency and forced frequency of the structure are matched, That process we call it as "RESONANCE". Its not recommonded to operate the structures at the resonance frequencies because if it is operated there are the chances of failure.

D) The identification of defects within a machine, reducing equipment failures and unscheduled downtime is increasingly demanded of condition monitoring technologies. Vibration analysis has proven to be one of the most effective tools for identifying mechanical and electrical faults within machinery. Most vibration measurements use a combination of on-line monitoring and offline (walk around) monitoring. Off line programs require the resources of a trained technician to walk from machine to machine to collect the vibration data.