(a) Perspective 1
(b) Perspective 2 Figure 4.17 (a) Comparison of simulated collapse to perspective 1; (b) comparison of simulated collapse to perspective 2. Based on this analysis, we found that the simultaneous failure of all core columns followed by the simultaneous failure of all exterior columns produces almost exactly the behavior observed in videos of the collapse. The computer time history model accounted for mass and acceleration during collapse in which an acceleration time dependent function accounted for impact resistance over time. Specifically, the simulated velocity and acceleration of the building in our SAP2000 model, shown in Figure 4.18, matches almost exactly with the motion measured by David Chandler (Chandler, 2010), including the approximately 2.5 seconds of free fall, shown in Figures 4.19 and 4.20 below.
106