Abstract: Pump-controlled Motor is often used to drive a mobile machine. Due to the random loads and highly demanding environments of such machines, the hydraulic systems are often hampered by breakdowns and the life of components are short. It is critically required to find out the dynamic behaviors of hydraulic systems when working in order to improve the design and the reliability of the machine. The best way is to do the investigations in the laboratory. And a semi-hardware type simulation and testing stand is necessary. This paper describes such a system in two ways: (1) the advantages and some design details of such a system; (2) How to find the. Load feedback characteristic parameters.

Key words: fusion welding, heat transfer and fluid flow, numerical simulation, research progress, weld pool behavior