Landing Gear of an aircraft can be modelled as a wheel with damper and spring attached horizontally.(adsbygoogle = window.adsbygoogle || []).push({});

I have to show that the equation of motion is given by

(I+mr^2)a + cr^2v + kr^2x = 0

where a= acceleration, v= velocity, x= displacement and spring stiffness = k and damping coefficient = c.

I realise i have use resultant forces = ma, and then substitute for friction into the sum of moments about the centre= 0.5(mr^2).

However, when i do this, i get an extra mr^3xtheta(double dot).

Am i missing the point with respect to intial conditions or is my maths just all over the place?

Help!

Cheers

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# Rectilinear and Rotational Motion

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