Modeling of structural cables

For many applications, including future giant telescopes, there is increased interest in structural cables. Usually integrated models, i.e. combined models of structures, optics and control systems are used for modeling of telescopes. Performance of structural cables is non-linear, so often a linearization is needed to include cable models in integrated models of telescopes. We present two different linear models describing static and dynamic performance of a cable near an equilibrium operating point. The models are "plug-in" models that in a black box form give end point forces as outputs, with end point movements as inputs. Using an example, we compare the two models and we outline the benefits of each of the models. Although we here focus on modeling of telescopes, the techniques are useful also for other applications.