Djonno possesses the unusual combination of being an excellent researcher and a very good writer. His work is directly publishable in mechanics and structural engineering journals.Graduation committee - Prof. Dr. Ir. J.G. Rots Dr. Ir. M.A.N. Hendriks Ir. M. Pari Dr. Ir. G.M.A. Schreppers Ir. L.J.M. Houben
Throughout the years, incremental iterative approaches have been shown to be excellent tools in describing the complex behaviour of structures. However, robustness issues arise for concrete structures due to the potential loss of convergence during the development of abrupt cracks. In order to overcome these robustness issues, the framework of sequentially linear analysis (SLA) has been proposed. The current SLA-framework is based on a fixed crack approach, potentially causing the development of severe spurious stresses. To this end, the sublayer model, which consists of several parallel layers, is proposed. The main idea is to mimick a rotating crack by a superposition of sublayers with a fixed crack direction. In his thesis, Djonno further elaborated and generalized the sublayer model. He showed that this model does indeed mimic a rotating crack, as less spurious stresses were observed, less wide localization bands found and more realistic collapse mechanisms were obtained.