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