$ This model illustrates that infinitesimal strain (calculated from nodal coordinates by $ LSPP) is invalidated by rigid body rotation. $ Observe that (1) tensorial x-strain written by LS-DYNA is in close agreement with $ infinitesimal x-strain during the dynamic relaxation phase (d3drlf) when the body $ is not rotating but (2) the infin. x-strain becomes nonphysically large when the $ the body rotates during the transient phase (d3plot) $ Interestingly, Green x-strain remains constant rather than varying sinusoidally as the $ body spins and Almansi x-strain tracks the tensorial x-strain closely. $ It should be noted that in this example, strains are small. *KEYWORD $_________________________________________ *database_secforc 0.0002 $ local x-force data from section1 should be constant $ local y-force data from section2 should be constant $ (OK in 971 R3 and R4, not OK in R2,7600.1224) *database_cross_section_set $ id, itype 1,1,,,,, 1, 2 1,1,,,,, 2, 2 $$ section3 outputs in global system 1,1,,,,, *set_node 1 4,16,10,22 *set_solid 1 4 *define_coordinate_nodes $$ FLAG must be 1 for local system of secforc to be updated $ FLAG, DIR 1,16,17,10, 1 2,16,17,10, 1, Y $______________________________________________________________ $ use objective stress update to prevent 'wandering' solution *control_accuracy 1,3 *database_binary_d3drlf 0.1e-3 *load_body_rz 1,1,2,0,0,0 *define_curve $ body load for transient phase set to zero 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,.000001,,,.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 *DATABASE_EXTENT_BINARY 0 0 0 1 0 0 0 0 0 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