Newmark Integrator for Dynamic Analysis

[NTMorris]

Hello,

I was looking into the Newmark integrator and saw that the implementation differed from the typical process in the textbooks I've read. OpenSees updates the displacement, velocity, and acceleration at each iteration, whereas many, such as Chopra, only update the displacement (or solve for the displacement increment).

They are both correct implementations of the Newmark method, but is there a textbook/reference I can please read that talks about the Newmark method in the way OpenSees has it?

Thanks,
Nicholas