$ Run this spinning bar problem first without damping_frequency_range and $ plot time histories of von Mises stress. $ The stress exhibits very mild oscillation with frequency of ~1000 Hz but otherwise $ the solution is good. The bar spins with constant velocity. $ Now introduce damping_frequency_range (commented out below). The spinning bar $ starts to drift and quickly stops spinning if the frequency range ratio $ Fhi/Flo is only 3 (1st line of input). If the Fhi/Flo is increased to 10, the bar no longer $ drifts although the angular velocity (and stresses) decline with time. *KEYWORD *damping_frequency_range $$0.01, 500,1500, 1 $$0.01, 500,5000, 1 0.001, 800, 8000, 1 *set_part 1 1 $ use objective stress update to prevent 'wandering' solution *control_accuracy 1,3 *control_hourglass 4,.03 *database_binary_d3drlf 0.1e-3 *load_body_rz 1,1,2,0,0,0 *define_curve $ body load for transient phase 1 0,0 1000,0 *define_curve $ body load for DR phase 2,1 0,0 1e-5,1000. 100,1000. *control_dynamic_relaxation 20,.0000001,,,.5 $20,.0001,,,.5 *control_structured *initial_velocity_generation 1,2, 1000. $ setting phase = 1 (vel applied AFTER deformation from DR) 0.,0.,0.,0.,0.,1., 1 *database_glstat 0.0001 *TITLE spinup.bar.k *CONTROL_TERMINATION 0.0200000 0 0.0000000 0 0.0000000 *CONTROL_TIMESTEP 0.0000000 0.7000000 0 0.0000000 0.0000000 0 0 *CONTROL_ENERGY 2 0 0 0 *DATABASE_BINARY_D3PLOT 0.0002000 0 *MAT_ELASTIC 1 3.00000-4 1.00000+7 0.3000000 *SECTION_SOLID 1 0 *PART 1 1 1 0 0 0 0 0 *NODE 1-5.000000000E+00-1.000000000E+00-2.000000030E-01 0 0 2-3.000000000E+00-1.000000000E+00-2.000000030E-01 0 0 3-1.000000000E+00-1.000000000E+00-2.000000030E-01 0 0 4 1.000000000E+00-1.000000000E+00-2.000000030E-01 0 0 5 3.000000000E+00-1.000000000E+00-2.000000030E-01 0 0 6 5.000000000E+00-1.000000000E+00-2.000000030E-01 0 0 7-5.000000000E+00 1.000000000E+00-2.000000030E-01 0 0 8-3.000000000E+00 1.000000000E+00-2.000000030E-01 0 0 9-1.000000000E+00 1.000000000E+00-2.000000030E-01 0 0 10 1.000000000E+00 1.000000000E+00-2.000000030E-01 0 0 11 3.000000000E+00 1.000000000E+00-2.000000030E-01 0 0 12 5.000000000E+00 1.000000000E+00-2.000000030E-01 0 0 13-5.000000000E+00-1.000000000E+00 0.000000000E+00 0 0 14-3.000000000E+00-1.000000000E+00 0.000000000E+00 0 0 15-1.000000000E+00-1.000000000E+00 0.000000000E+00 0 0 16 1.000000000E+00-1.000000000E+00 0.000000000E+00 0 0 17 3.000000000E+00-1.000000000E+00 0.000000000E+00 0 0 18 5.000000000E+00-1.000000000E+00 0.000000000E+00 0 0 19-5.000000000E+00 1.000000000E+00 0.000000000E+00 0 0 20-3.000000000E+00 1.000000000E+00 0.000000000E+00 0 0 21-1.000000000E+00 1.000000000E+00 0.000000000E+00 0 0 22 1.000000000E+00 1.000000000E+00 0.000000000E+00 0 0 23 3.000000000E+00 1.000000000E+00 0.000000000E+00 0 0 24 5.000000000E+00 1.000000000E+00 0.000000000E+00 0 0 *ELEMENT_SOLID 1 1 1 2 8 7 13 14 20 19 2 1 2 3 9 8 14 15 21 20 3 1 3 4 10 9 15 16 22 21 4 1 4 5 11 10 16 17 23 22 5 1 5 6 12 11 17 18 24 23 *END