Doc. dr. Vito Tič, univ. dipl. inž., prof. dr. Darko Lovrec, univ. dipl. inž., Marijana Milković, mag. inž., prof. dr. Nenad Gubeljak, univ. dipl. inž., vsi Univerza v Mariboru, Fakulteta za strojništvo

Abstract:
Material fatigue testing machines are used in laboratory and industrial environments for testing and research in fracture mechanics and are typically operated by servo hydraulic or servo pneumatic actuators. They contain an increasing number of electronic and microprocessor-controlled components, with which they achieve appropriate dynamics and the ability to store and process signals.

The paper describes the design, implementation and operation of a flexible mechine for testing the dynamic strength of materials based on a linear electro-hydraulic servo axis with closed loop force control. To control the components, a Beckhoff multi-core controller is installed, which simultaneously runs a control program with real-time force control, as well as a human-machine interface in the Windows environment. The presented machine is capable of achieving forces up to 40 kN at test speeds of up to 20 Hz.

Keywords:
servo hydraulics, force control, high dynamic operation, material fatigue testin