1、DR convergesSIDR=1(DR phase)SIDR=0(transient phase)Dynamic Relaxation information is writtento the screen.The transient phase starts when the convergence tolerance or a Specified termination time is reached.Convergence plot from relax fileKinetic Energy plot from relax filegContactGround is constrai
2、ned One of the tires from NCACs Ford 250 was used inthis example but without the control volume.A gravity load is applied in the transient phase as a constant curve,which makes the tire bounce during the simulation(time=1)as seen when plotting the Z-displacement for a node on the tirerim.This model
3、is used to investigate the behavior of Dynamic Relaxation.Node ConsideredDynamic Relaxation was added to the model using a ramped load curve for the DR phase,i.e.,load curve LCIDDR(*LOAD_BODY_Z)has SIDR(*DEFINE_CURVE)set to 1.The load is ramped in curve LCIDDR over 2000 time steps.The*CONTROL_DYNAMI
4、C_RELAXATION parameters are all set to default and the deck is the same as before.A No DRB With DRThree different settings of the convergence tolerance,DRTOL,were tried:1e-3(default),1e-4 and 1e-6.The tolerance is the only change in the model.nThe value of DRTOL offers a tradeoff between run time an
5、d amplitude of residual dynamic oscillation.Load TimePreload Transient Load Mass Damping Coef TimeLoad Timet1t1t2t2TimeTimeDynamic relaxation(LCID1)+Transient Phase(LCID2)Transient Phase Only(LCID2)if LCID1=0TimeContact Stiffness Scale FactorContact Stiffness Scale FactorContact Stiffness Scale Factor1.01.01.0Example:http:/ of preloaded boltsTarget bolt stress is achieved without multiple trial simulations.Example:http:/ platesBoltRigid beamsBolt beamExample of preloaded bolt
