23. Vibration by Mode Superposition

MIT 2.003SC Engineering Dynamics, Fall 2011
View the complete course: ocw.mit.edu/2-0...
Instructor: J. Kim Vandiver
License: Creative Commons BY-NC-SA
More information at ocw.mit.edu/terms
More courses at ocw.mit.edu

[@georgesadler7830]

DR. Vandiver, this lecture is another powerful demonstration and real world analysis of Vibration by Mode Superposition. Vibrations is a part of all mechanical/electrical systems.

[@Anomander888]

I'd attend this mans lectures all day

[@alinoureddine4942]

Helpful Content for Mechanical Engineering students.

[@AJ-et3vf]

Agree, I'm taking mechanical vibrations currently and I watch these as we move along.

[@brainstormingsharing1309]

Absolutely well done and definitely keep it up!!! 👍👍👍👍👍

[@Rayquesto]

Something is not right about 6:17. Should be m*mu*g/2; It's impossible to have a zero Fapplied or other horizontal force being zero (other than Ffriction on little m), unless the block is slipping.

[@MG-yg3fn]

Isn't there a 3rd mode at 43:20 which would be if you twisted the block so that it revolves back and forth without moving it's center of mass to the sides?

[@arun6346]

All mode shapes should be considered or one single large mode of earthquake force should be considered in determining horizontal earthquake load or EL in building structure design in civil engineering.

[@markwashington2412]

What is the difference between a and u (where a is the amplitude as described here, and u is the mode shape described in other videos such as part 24 and 25)

[@patrickamstad5091]

@1:08:31 : How is it possible, that the two mode shape (Eigenvectors) are linearly dependent?!

[@tornjak096]

hmmm I think he should take A2 to be a2 and than the second eigenvector would be (a1/a2 ; 1), that is my opinion

[@tornjak096]

Or these are 4 unknowns parameters (a11,a21, a12, a22) and we can always chose one from each eigenvector as free parameter

[@SuperNeutronX]

Thank you very much! super

[@xinglongchen4396]

could you please tell me what is the difference between wi and w. Is w a scalar or a matrix? If it is a scalar, can it represent n different natural frequency? If it is a matrix, when multiplying [M]-1, [M]-1 should be placed at the left side of w squared

[@tornjak096]

it is characteristics polynomial which has more solutions. So a is also vector but you have n independent vectors so you can represent it like V matrix but in the characteristics equation it is one vector, just like lambda is constant (or omega_i^2) but it has n values of that constants.

[@kailashsingh9737]

Very nice sir hi ji

[@josiecandy3841]

:)

[@ColocasiaCorm]

I should never be an engineer or ever associated with mit