High-accuracy numerical model of the Southern African large telescope mirror support truss

In order to calibrate the primary mirror of the Southern African large telescope, a high-accuracy numerical model of the existing mirror support truss and its actual, current behavior is required. In this investigation, structural optimization techniques are used to tune a numerical model so that it accurately matches the measured output of a structure under a given load or combination of loads. A methodology for obtaining an accurate numerical model of such a structure by first investigating the behavior of the different strut types before attempting to model the structure as a whole is presented. This method yielded vast improvements in the numerical accuracy of a smaller, simpler laboratory structure's numerical model. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)