DAMPING IN DYNAMIC ANALYSIS...

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 Hey guys,

Today we are talking about the most important topic, which is damping...

Previously, we talked about the static, Transient, & Dynamic analysis, now we know that the damping effect is considered in the transient and dynamic analysis. So, what is damping? The important thing to know, that damping can be good as well as bad according to your use of the system. 

            The damping is such a phenomenon when the displacement of any object happens there is damping that get produced. A system can be so damped that it cannot vibrate. Actually friction is also a type of damping. The damping force dissipates the energy in the material generally in the internal thermal energy. Talking about the static analysis where if the object is subjected to a certain load the displacement is happening in which we cannot consider the damping effect for the object. 


            But if talking about the dynamic analysis of any system or like complex problems such as any machine or the large structure and the bridge we consider the damping effect. So that the damping decreases the vibrations through removing energy which is resistance to motion in components. For rotating equipment, damping is necessary to control vibrations and prevent them from damaging the rotor, bearings, or other components in the machine.

            Various types of damping make up the damping matrix [B] in dynamic solutions. Therefore, the damping matrix consists of several matrixes:

( This matrix Reference is taken from the Autodesk: https://knowledge.autodesk.com/search-result/caas/CloudHelp/cloudhelp/2017/ENU/NINCAD-SelfTraining/files/GUID-6D2ABB14-6285-441B-883F-358F9E37FA8E-htm.html )

The damping is the unit less quantity which is represented in the factor ZETA if the factor is <1 it is underdamped motion if it is >1 it is overdamped and it is  =0 it is undamped and if =1 then it is critically damped.

If you hadn't had any damping in the world, it would cause a lot of problems...

Consider the ball, if you through it on the ground it will roll only because of the initial force but you know that the ball will stop after some time due to friction between the ground and the surface of the ball. It rolls for some time because the area with ground is very small but if we consider the cube it will stop in less time here the area of contact is large.

Damping is basically the same thing… friction is only one example of dynamic system damping. 

Also, you can consider the example of viscous damping the damping due to fluid or air.

We use a lot of « static » analysis in FEA… but in reality, most of the dangerous phenomena which are dangerous are dynamic…

That’s why a basic dynamic analysis is the « modal » analysis that uncovers the core mode of vibrations which can potentially create problems when excited by some dynamic load. So to avoid it.... we use damping.

            There are various types of damping like Vibration, Magnetic, Viscous, Radiation, Landau dampings, and many more 

            So, the damping is based on what type of problem you are solving in your model.

For more details subscribe to the blog and if have any query please let me know...

(PS: For the mathamatical derivations about the damping please visit above autodesk link   )

THANK YOU !!!

HAPPY LEARNING!!!😃😃😃

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