What Is a Servo-Hydraulic Testing Machine, and How Does It Work?

Servo-hydraulic machines are multicomponent systems designed for static and dynamic fatigue testing of materials, parts, and assemblies. This equipment allows you to study the parameters of sample deformations provoked by the impact of loads of a certain force and direction. This kind of research is in demand in research institute laboratories to assess experimental objects’ technical and dynamic characteristics. Not without servo-hydraulic testing machines and many production departments of quality control. There, with their help, the compliance of products with regulated standards is checked.

The range of functions of the servo-hydraulic testing machine is wide and varied. It includes manipulations and measuring actions that are aimed at studying the reactions of the sample that appear during testing:

  • For high- and low-cycle fatigue;
  • Fracture toughness;
  • Thermo mechanical fatigue;
  • Fatigue crack growth and propagation;
  • Tension, compression, bending, shear.

Main Components of Servo-hydraulic Testing Machines

The main task of any servo hydraulic system is to provide conditions for testing samples with force and dynamic loads, converting the resulting deformations into electrical signals and deciphering the results. These processes are implemented due to the presence in the design of the equipment:

Power frame – a fixed base with steel guide columns fixed on it. With the help of stoppers, the traverse is fixed on the latter. In a stationary state, it outlines the working space and moves along the columns; it changes its boundaries;

Power hydraulic drive mounted on the frame. It works under the influence of pressure, the source of which is a hydraulic station;

The force sensor and displacement sensor- The first determines the magnitude of the force generated by the hydraulic drive and applied to the tested object. The function of the second is to measure the linear displacement of the movable element of the power drive;

Holding, fixing, and gripping devices- With their help, the test sample is installed between the movable drive element and the fixed elements of the power frame;

Controller – measuring-computing and control complex- It receives measures and records electrical signals from force and displacement sensors.

The control of the servo-hydraulic testing machine, the processing and analysis of the information received, and the preparation of reports on the tests carried out are carried out by using offline software. It is installed on a computer from a special disk.

Servo-hydraulic testing machine

How do Servo-hydraulic works?

The load is applied by the hydraulic piston inside the test frame. Closed-loop application speed control load, controlled by an electronic device, model MD2i.

Power-operated high-pressure hydropower plants are housed in a sealed anti-pollution unit with very low noise levels for pressure generation.

The adaptive flow of the pump according to the requirements of the machine’s main control system. The device is installed on the device’s electrical panel and works completely independently of the computer connected via USB 2.0 or Ethernet.

Adjustment of hydraulic fluid flow (and thus adjustment of load speed) is performed by a high-performance control servo valve mounted on the manifold (distribution block). The hydraulic unit, manifold, and servo valve are located inside the work table and in a set of four shock absorbers that prevent vibrations from transmitting to the frame.

This way, users can replace their computers on their own, as needed, without technical assistance or without having to reset or reset the device.

Servo-hydraulic testing machines are used in research activities to determine the strength characteristics of materials, parts, and prefabricated structures and to measure the resistance of objects under study to various mechanical loads. The servo hydraulic system is no less popular in quality control of products for the automotive, railway, construction, aerospace, and other industries.