12. Finite Element equations and the Direct Stiffness method

Questions and discussion for this lecture live here. Fire away by hitting Reply below :fire:

Sorry if this question doesn’t make sense but Around 10:20, why did you subtract delta x2 from from delta x1 if the force Fx1 and Fx2 are not same/equal? Again sorry for my poor english.

Hey @Subashs29,
We subtract the delta_x2 from delta_x1 because it’s the displacement at node ‘i’ we’re interested in (when considering the first equation), so we need to remove the influence of the displacement at node ‘j’ since this is captured in the second equation when considering the displacement due to F_x2.

Feel free to follow up if you’re still not clear.