Abstract
In this study, the optimal design of a mechanism consisting of multiple bodies including a hydraulic cylinder as actuator, is carried out. Multibody dynamics enable the analysis of motion and forces and build the base for numerical design optimization of such systems. To consider also the hydraulic behavior of the actuator, hydraulic equations are included into the system equations. Direct sensitivity analysis is applied by a semi-analytic approach in combination with Newmark-β time integration with the Newton–Raphson method. The introduced methodology is applied to a Tyrolean weir cleaning mechanism and design optimization of the mechanism is shown. The approaches are general and therefore can be applied to other multibody systems or can be further extended to other fields of multiphysics simulations.