The data file for this exercise is located in directory: mech_001\Exercises\Case1E\Data. Look for ! TODO  text in the datafile and follow the instructions.

 

The overshoot in the stress at time t=1.0 is due in part to the instantaneous change from a surface load increasing at constant rate to a constant surface load.  This effect can be minimized by utilizing a nonlinear time curve where there is a smoother transition from increasing load to constant load; e.g. an S-Curve ramp.

 

The S-Curve provides a smoother transition of the loading state at both the start and end of the load increase.

 

 

 

The results are visualized by plotting the high definition history data for global energy and points output in files mech_001_2d_Case1e_000.hdh and mech_001_2d_Case1e_001.hdh respectively.

 

The time history of stress shows that the S-Curve ramp reduces the overshot at time t=1.0 relative to the linear ramp case (Case 1D).

All curves exhibit only minor dynamic oscillations and the solution is close to quasi-static.   Decreasing the critical time step further would further reduce the amplitude of the oscillations at the expense of greater CPU time.