International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 06 | June-2017
p-ISSN: 2395-0072
www.irjet.net
A REVIEW ON DYNAMIC ANALYSIS OF MACHINE STRUCTURE Mahmood Gaznavi1, Anil Kumar G2, Satheesh.J 3, Madhusudhan T4 M.Tech student, Mechanical Department, Machine Design, SJBIT, Bengaluru, India 2 Associate Professor Mechanical Department, SJBIT, Bengaluru, India. 3 Professor Mechanical Department, SJBIT, Bengaluru, India 4Professor Mechanical Department, SJBIT, Bengaluru, India ---------------------------------------------------------------------***--------------------------------------------------------------------1
Abstract - Dynamic analysis of machine structure is
unavoidable or even desirable. In this case, the goal may be to understand the effect on the structure, or to control or modify the vibration, or to isolate it from the structure and minimize structural response.
necessary to ensure not only the comfort of the users, but ensure good conditions for the operation of equipment supported. With increase in the rapid development of changing technology there is a need for proper optimization to increase the efficiency& job accuracy. The objective of dynamic analysis is to analyze the behavior of a structure, when subjected to forcing function under resonance condition. This paper outlines the dynamic analysis of machine structure under different natural frequencies & mode shape by using FEM packages. Vibration in a machine structure due to unbalancing of masses is a major challenge which can be analyzed & overcome.
Free vibration is the natural response of a structure to some impact or displacement. The response is completely determined by the properties of the structure, and its vibration can be understood by examining the structure's mechanical properties. For example, when you pluck a string of a guitar, it vibrates at the tuned frequency and generates the desired sound. The frequency of the tone is a function of the tension in the string and is not related to the plucking technique. Forced vibration is the response of a structure to a repetitive forcing function that causes the structure to vibrate at the frequency of the excitation. For example, the rear view mirror on a car will always vibrate at the frequency associated with the engine's RPMs. In forced vibration, there is a relationship between the amplitude of the forcing function and the corresponding vibration level. The relationship is dictated by the properties of the structure.
Key Words: Dynamic analysis, vibration, modal analysis, FEM packages, frequency & mode shape. 1. INTRODUCTION Dynamics of structures studies movements of bodies caused by forces applied to them and also the forces that cause movements in structures. Structural Dynamics testing and analysis contributes to progress in many industries, including aerospace, auto making, manufacturing, wood and paper Production, power generation, defense, consumer electronics, telecommunications and transportation. The adequate dynamic analysis of structures implies the creation of models that allow converting a pre-established entity, in a complex way, into something that the current resources can understand and model.
1.2 Dynamic Analysis
1.1 Vibration
Rafael Marin Ferro [1] conducted a performance check of support frame structure to estimate the dynamic loads caused by rotating equipment on supports using computational models with strap software. The paper concluded that fully rigid structures is suitable for dynamic structure point of view
Dynamic analysis can be used to determine the vibration characteristics (natural frequencies and mode shapes) of a structure or a machine component while it is being designed. It also can be starting point for another, more detailed, dynamic analysis, such as a transient analysis, a harmonic analysis, or a spectrum analysis. Dynamic analysis is the study of the dynamic properties of structures under vibrational excitation.
2. LITERATURE REVIEW
The term vibration describes repetitive motion that can be measured and observed in a structure. Unwanted vibration can cause fatigue or degrade the performance of the structure. Therefore it is desirable to eliminate or reduce the effects of vibration. In other cases, vibration is
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