Affiliation:
1. Graz University of Technology
Abstract
Multi-axial mechanical testing with servo-hydraulic cylinders is used as essential tool within the development and manufacturing process of mechanical components and structures, enabling the experimental validation of the fatigue behavior and related mechanical endurance limits. In this paper we derive the analytical model of servo-hydraulic cylinders feasible for fatigue tests to enable the incorporation of the derived actuator dynamics within multi-axis test control strategies. Our derived cylinder model includes the test cylinder with attached position sensor, and a state-of-the-art servo valve. Based on the obtained cylinder dynamics we propose a simplification to a low order cylinder model, highly desirable for reducing overall system complexity in order to develop ease-of-use controllers of high performance for multi-dimensional test rigs. We compare the simulated output of the derived actuator models with the measured data from a real world test cylinder system. The obtained results show that the obtained system model accurately describes the dynamic properties of a real world test cylinder, and furthermore validates the process of model simplification for efficient control of such cylinders as part of low-bandwidth multi input multi output servo-hydraulic test systems.
Publisher
Trans Tech Publications, Ltd.