Time harmonic analysis of concrete arch dam-reservoir systems utilizing GN high-order truncation condition

In present study, the dynamic analysis of concrete arch dam-reservoir systems is formulated by FE-(FE-TE) approach. In this technique, dam and reservoir are discretized by solid and fluid finite elements. Moreover, the GN high-order condition imposed at the reservoir truncation boundary. This task is formulated by employing a truncation element at that boundary. It is emphasized that reservoir far-field is excluded from the discretized model. The formulation is initially explained in details. Subsequently, the response of idealized Morrow Point arch dam-reservoir system is obtained for two fully reflective and absorptive reservoir bottom/sidewalls conditions for all three types of excitations. Different Orders of GN condition are considered and convergence process is evaluated. Furthermore, the results are compared against exact solutions which are based on rigorous FE-(FE-HE) approach. It is shown that the technique converges prior to beginning of instability problems which is known to exist for high orders in GN condition. It must be emphasized that although time harmonic analysis is considered in the present study, the main part of formulation is explained in the context of time domain. Therefore, the approach can easily be extended for transient type of analysis.