$ Internal energy for seatbelt not computed prior to v. 970 $ Even in 970, glstat energy ratio is not good $ $ The timestep for a seatbelt element is calculated in similar fashion $ to that of a discrete (spring) element but with a $ reduction factor of 0.6 applied. I assume the 0.6 is to promote stability. $ $ dt = timestep scale factor * sqrt(m/k) * 0.6 $ $ k = F/deltaL = F/(eps * L) = (initial slope of F vs. eps curve) / L $ = 1e5/50 $ L = current element length $ $ m = sum of nodal masses $ $ nodal mass = tributary belt length * mass per unit length $ = 50 * 3.e-7 $ *KEYWORD *CONTROL_TIMESTEP $,0.8 $$ DT2MS seemingly does not add mass to seatbelt element (nothing in glstat or matsum) $$ but timestep is affected by DT2MS ,.8,,, -2.7e-5 *section_beam 20,2 1,1,1,1,1,1 *part 20,20,20 *mat_elastic 20,1.e-7,200,.3 *element_beam 20,20,18,118,218 *constrained_nodal_rigid_body 20 *set_node 20 18,118 *control_structured *TITLE au03 : Slip ring and retractor *CONTROL_TERMINATION 10.00E-02 0 0.000E+00 0.000E+00 0.000E+00 *DATABASE_GLSTAT 2.000E-04 *CONTROL_SHELL 0.000E+00 0 0 0 0 0 *CONTROL_CONTACT 0.000E+00 0.000E+00 0 0 2 0 0 0 0 0 0 0.000E+00 *CONTROL_ENERGY 2,2,2,2 *DATABASE_HISTORY_NODE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 *DATABASE_BINARY_D3PLOT $ 2.000E-04 1 4.e-4 *DATABASE_BINARY_D3THDT 2.000E-04 0 *DATABASE_BINARY_D3DUMP 99999 *DATABASE_BINARY_RUNRSF 99999 *DATABASE_BINARY_INTFOR 2.000E-04 0 *DATABASE_EXTENT_BINARY 0 0 0 0 0 0 0 0 0 0 *DATABASE_matsum 2.000E-04 0 *DATABASE_SBTOUT 2.000E-04 0 *NODE 1 0.00000000E+00 0.00000000E+00 0.00000000E+00 0 0 2 0.00000000E+00 0.00000000E+00 0.50000000E+02 0 0 3 0.00000000E+00 0.00000000E+00 0.10000000E+03 0 0 4 0.00000000E+00 0.00000000E+00 0.15000000E+03 0 0 5 0.00000000E+00 0.00000000E+00 0.20000000E+03 0 0 6 0.00000000E+00 0.00000000E+00 0.25000000E+03 0 0 7 0.00000000E+00 0.00000000E+00 0.30000000E+03 0 0 8 0.00000000E+00 0.00000000E+00 0.35000000E+03 0 0 9 0.00000000E+00 0.00000000E+00 0.40000000E+03 0 0 10 0.50000000E+02 0.00000000E+00 0.40000000E+03 0 0 11 0.10000000E+03 0.00000000E+00 0.40000000E+03 0 0 12 0.15000000E+03 0.00000000E+00 0.40000000E+03 0 0 13 0.20000000E+03 0.00000000E+00 0.40000000E+03 0 0 14 0.25000000E+03 0.00000000E+00 0.40000000E+03 0 0 15 0.30000000E+03 0.00000000E+00 0.40000000E+03 0 0 16 0.35000000E+03 0.00000000E+00 0.40000000E+03 0 0 17 0.40000000E+03 0.00000000E+00 0.40000000E+03 0 0 18 0.00000000E+00 0.00000000E+00 0.40000000E+03 0 0 118 0.00000000E+00 0.00000000E+00 0.50000000E+03 7 7 218 1.00000000E+00 0.00000000E+00 0.40000000E+03 0 0 19 0.00000000E+00 0.00000000E+00 0.00000000E+00 0 0 20 0.00000000E+00 0.00000000E+00 0.00000000E+00 0 0 21 0.00000000E+00 0.00000000E+00 0.00000000E+00 0 0 22 0.00000000E+00 0.00000000E+00 0.00000000E+00 0 0 23 0.00000000E+00 0.00000000E+00 0.00000000E+00 0 0 $*ELEMENT_MASS $ 1 17 0.50000E-01 $ 2 18 0.50000E-01 $ 3 19 0.50000E-01 *ELEMENT_SEATBELT 101 1 1 2 0 0.0000E+00 102 1 2 3 0 0.0000E+00 103 1 3 4 0 0.0000E+00 104 1 4 5 0 0.0000E+00 105 1 5 6 0 0.0000E+00 106 1 6 7 0 0.0000E+00 107 1 7 8 0 0.0000E+00 108 1 8 9 0 0.0000E+00 109 1 9 10 0 0.0000E+00 110 1 10 11 0 0.0000E+00 111 1 11 12 0 0.0000E+00 112 1 12 13 0 0.0000E+00 113 1 13 14 0 0.0000E+00 114 1 14 15 0 0.0000E+00 115 1 15 16 0 0.0000E+00 116 1 16 17 0 0.0000E+00 $ seatbelt elements inside retractor which can be paid out 117 1 1 20 551 0.0000E+00 118 1 20 21 551 0.0000E+00 119 1 21 22 551 0.0000E+00 120 1 22 23 551 0.0000E+00 *ELEMENT_SEATBELT_SLIPRING 99991 108 109 0.000E+00 18 *ELEMENT_SEATBELT_RETRACTOR $ 551 19 101 6661 0 0 0 $ no sensor 551 19 101 $ TDEL and PULL are zero; thus, curve 55 becomes active immediately $ after sensor is triggered. $ Curve 55 has initial tension to pull on belt during unlocked phase 0.000E+00 0.000E+00 55 66 5.000E+01 *ELEMENT_SEATBELT_SENSOR 6661 3 0 1.000E-02 6662 3 0 2.000E-03 *PART Part for belt material 1 1 1 1 0 0 *SECTION_SEATBELT 1 *MAT_SEATBELT 1 3.000E-07 33 33 1.000E+01 $ 1 3.000E-07 33 34 1.000E+01 *DEFINE_COORDINATE_SYSTEM 1 0.0 0.0 0.0 1.0 0.0 0.0 0.0 1.0 0.0 *BOUNDARY_SPC_SET 1 1 0 1 1 0 0 0 *SET_NODE_LIST 1 17 *BOUNDARY_SPC_SET 2 1 1 1 1 0 0 0 *SET_NODE_LIST 2 $ 18 19 19 $*INITIAL_VELOCITY_NODE $ 17 1.340E+04 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 *boundary_prescribed_motion_node $17,1,2, 50 17,1,0, 51 *define_curve 50 0,0 .02,100 1,100 *define_curve 51 0,0 .01,5000 .02,5000 .03,0 1,0 *DEFINE_CURVE 1 0 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.00000000E+00 0.99999997E-05 0.10000000E+01 0.99999997E-05 *DEFINE_CURVE 2 0 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.00000000E+00 0.10000000E+05 0.99999998E-02 0.10000000E+05 0.17999999E-01 -0.10000000E+05 0.10000000E+01 -0.10000000E+05 *define_curve 33 0,0 1,1e5 2,3e5 *define_curve 34 0,0 1,1.5e5 2,4.5e5 *DEFINE_CURVE 3 0 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.00000000E+00 0.00000000E+00 0.24999999E-02 0.10000000E+03 0.25000000E-01 0.10000000E+04 0.56000002E-01 0.48000000E+04 0.66000000E-01 0.70000000E+04 0.20000000E+01 0.50000000E+06 *DEFINE_CURVE 4 0 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.00000000E+00 0.00000000E+00 0.20000000E-01 0.10000000E+04 0.35000000E-01 0.48000000E+04 0.44000000E-01 0.70000000E+04 0.50000000E+00 0.50000000E+06 *DEFINE_CURVE 55 0 0.000E+00 0.000E+00 0.000E+00 0.000E+00 $ 0.00000000E+00 0.00000000E+00 0.00000000E+02 0.05000000E+04 0.20000000E+02 0.10000000E+04 0.30000000E+02 0.20000000E+04 0.40000000E+02 0.50000000E+04 0.50000000E+02 0.10000000E+06 *DEFINE_CURVE 66 0 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.00000000E+00 0.00000000E+00 0.50000000E+01 0.10000000E+04 0.10000000E+02 0.30000000E+04 0.20000000E+02 0.10000000E+06 *DEFINE_CURVE 7 0 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.00000000E+00 0.00000000E+00 0.24999999E-02 0.20000000E+05 0.49999999E-02 0.00000000E+00 0.10000000E+01 0.00000000E+00 *END