I wrote my own input file for a dynamic calculation in ConFem, but the program calculates useless results. The load-displacement graph should also show an oscillation similar to your results of example 03-9.
You have to define a density in your material model, otherwise the mass of the material will be ignored for the solution of the equations of motion, because the fact, that the acceleration term becomes 0.
Make also sure, that you are using consistent units. In case of using “MN” and “m”, the density has to be appropriately converted: 2500kg/m**3 -> 2500 MN*s**2/m**4 * 10**(-6)= 2.5e-3 MN*s**2/m**4