Hi,

I am new to dynamic analysis and have a question regarding base excitation. I am interested in obtaining a frequency response (or amplification) curve that shows how the dynamic amplification factor—defined as the ratio of the structure displacement to the base displacement (X/Y)—varies with the excitation frequency ratio, r = w_b/ω_n, where w_b is the frequency of the base and ω_n is the natural frequency of the system. My goal is to get a plot like this:

Also, is it possible to obtain both the transient and steady-state responses when using base excitation in Abaqus ? Any help would be much appreciated.

Here is my input file step setup for base excitation:

*Include, input=MESH.inp
*Include, input=SET.inp
*Include, input=SECTION.inp
*Include, input=MATERIAL.inp
*BOUNDARY BC, 1, 6, 0
*AMPLITUDE, VALUE=RELATIVE, INPUT=QUAKE.AMP, NAME=EQ
*RESTART, WRITE, FREQUENCY=100
*STEP *FREQUENCY, EIGENSOLVER=LANCZOS, SIM=NO
10,
*EL PRINT, FREQUENCY=0
*NODE PRINT U,
*MODAL FILE
*OUTPUT, FIELD
*END STEP
*STEP Acceleration
*MODAL DYNAMIC .01, 2.
*SELECT EIGENMODES, GENERATE 1,6,1
*MODAL DAMPING 1,6
*BASE MOTION, DOF=2, AMPLITUDE=EQ, SCALE=386.09
*PRINT, FREQUENCY=50
*OUTPUT, FIELD, FREQUENCY=1
*NODE OUTPUT U, TU, V, TV, A, TA,
*ELEMENT OUTPUT S
*NODE OUTPUT, NSET=NOUT U, V, A, TA
*ENERGY OUTPUT, VARIABLE=ALL
*END STEP