Hi, I am a new Abaqus user, and I want to do nonlinear time history analysis on Abaqus. But I am having diffuclty understanding how Abaqus applies an acceleration time history. From what I have read, I apply the acceleration amplitude as an accleration boundary constraint in the desired direction. But it yields wrong results even when I work with simple inputs. Any idea on how to apply a ground motion and carry out earthquake time history analyses?