The analysis was made on the high-speed digital computer at the University of Illinois
Digital Computer Laboratory for the normalized accelerograms for the earthquakes. The
results are plotted in Fig. 21 for a symmetrical resistance function, in which the resistance is
rigid-plastic but having the same value in each direction of motion. It appears from Fig. 21
that the results are bounded by the expression for energy V2/2gN, and also by the maximum
displacement y,, of the ground. Where the value of N approaches the maximum earthquake
acceleration, there is a reduction in response from that given by the energy expression, as
shown by the equation in the lower right-hand part of the figure, in which the correction factor
derived in equation (23) appears to be applicable. Apparently this is important only beyond
a value of N/A greater than 0.5.