The WAW-600E microcomputer controlled electro-hydraulic servo universal testing machine adopts a bottom mounted oil cylinder host, mainly used for tensile, compression, and bending tests of metals and non-metals. Suitable for fields such as metallurgy, construction, light industry, aviation, aerospace, materials, colleges, research institutions, etc. The experimental operation and data processing comply with the requirements of GB/T 228.1-2021 "Tensile testing of metallic materials - Part 1: Room temperature test method". The addition of corresponding accessories on this machine is suitable for small batch and internal enterprise testing, and is not suitable for large-scale high-load testing laboratories such as steel mills or third-party testing companies.

2. Scheme Description

2.1 Host

The main engine is designed with a safety factor of 1.2 times, using a four column double screw, oil cylinder bottom mounted main engine, and high-precision spoke type load sensors for force measurement. The force measurement range is wide (the minimum can reach 1% of the maximum force value), and the accuracy is high (the force value can reach 0.5 level accuracy, far higher than the oil pressure sensor).
The stretching space is located above the host, and the compression and bending test space is located between the lower crossbeam of the host and the workbench. The whole machine is shown in Figure 1:

 The appearance of Figure 1 is subject to the actual product

2.2 Transmission system

The lifting of the lower crossbeam adopts a motor driven by a reducer, chain transmission mechanism, and screw pair to achieve adjustment of stretching and compressing space.

2.3Hydraulic system

The hydraulic principle is shown in the following figure, which is a load adaptive oil inlet throttle speed control system.

Figure 2 Hydraulic schematic diagra

The hydraulic oil in the oil tank is driven by a motor to enter the oil circuit through a high-pressure oil pump. It flows through a one-way valve, high-pressure oil filter, differential pressure valve group, servo valve (proportional valve), and enters the oil cylinder. The computer sends control signals to the servo valve (proportional valve) to control the opening and direction of the servo valve (proportional valve), thereby controlling the flow rate of hydraulic oil entering the cylinder and achieving control of constant speed test force, constant speed displacement, etc.

2.4. Software system

The experimental software is based on the Windows operating platform and has programmable functions. Multiple experimental modes, such as constant velocity force control, constant velocity displacement control, force retention, displacement retention, etc., can be combined to meet the requirements of various experimental methods to the greatest extent possible. It realizes various functions such as data display, curve drawing, data processing, storage and printing required for experiments; By sending control signals to the proportional servo valve through the computer, the opening and direction of the proportional servo valve are controlled, thereby controlling the flow rate entering the oil cylinder and achieving control of constant velocity test force, constant velocity displacement, etc. It has complete file operation functions, such as storing test reports, test parameters, and system parameters in a file format. The system is managed at a hierarchical level, and all system parameters are open to expert level users, ensuring flexible and reliable use of the system.

2.4.1software interface

· Integrating fully digital electro-hydraulic servo closed-loop control, data processing, and data analysis
· It has complete file operation functions, such as storing test reports, test parameters, and system parameters in a file format.
· Support various commercial general-purpose printers.
· The control system is supported by a software system and is easy to upgrade.
· The main interface of the software integrates all functions of daily material testing operations, such as sample information input, sample selection, curve drawing, data display, data processing, data analysis, and experimental operations. The experimental operation is simple and fast.
The general interface of the software is as follows (for reference only):

The computer screen displays test force, cylinder displacement, loading rate, and deformation test data, and draws various test curves such as time test force/deformation, 

deformation test force, etc; Automatically perform data processing, and the data processing method meets the requirements of GB228-2021 standard, including yield points, maximum force points, various specified non proportional stress points, and various specified full elongation stress points; Simultaneously meeting the pressure testing requirements of the testing machine;
· The software also provides data analysis functions to meet the needs of experimental personnel for experimental analysis and data processing for special experiments.

· Has strong graphic operation functions, such as dynamic test curve and digital display function, graphic enlargement and truncation function, cursor following display function, etc;
· Adopting VXDs high-speed data acquisition technology to achieve multi-channel (up to 16 channels) high-speed data acquisition;
· The system has a complete file operation function for storing test curves and test data; At the same time, experimental data can be stored in ASCII format for users to perform secondary data processing;
Capable of outputting single piece test reports and printing batch test reports;
Hydraulic clamping oil source: an independent low-noise hydraulic clamping oil source that controls the clamping and loosening of the chuck.

2.5. Safety protection devices

2.5.1.When the test force exceeds the set protection value or the maximum test force by 2% to 5%, overload protection is applied and the system is unloaded.
2.5.2.When the piston reaches the upper limit position, the stroke protection and servo oil pump motor stop.
2.5.3.In case of emergency, press the emergency stop button to shut down the power.

2.6. Accessories

The complete set of attachments includes: stretching attachments and compression attachments.

2.7. Other

Installation and debugging tools, seals, user manuals, certificates of conformity, packing lists, etc. can be found in the accompanying technical documents.

3. Main Performance Technical Indicators

3.1     Maximum test force： 600KN    
3.2     Test force measurement range kN: 2%-100% FS
3.3     Relative error of test force indication : ≤ ± 0.5% of indication value
3.4     Displacement measurement resolution mm:0.01    
3.5     The relative error of deformation measurement indication     
            complies with the provisions of Class 1 extensometers in JB/T 6146-2007 Technical Conditions for Extensometers (non-standard)
            Gauge distance 50, deformation 10mm
3.6     Maximum tensile test space mm:600(including cylinder stroke)
3.7     Maximum compressed space mm:500    
3.8     piston stroke mm: 200
3.9     Round jaw clamping diameter mm: Φ13- Φforty
3.10     Flat jaw clamping range :0-15
3.11     Pressure Plate Size :120
3.12     Clamping method :Hydraulic clamping
3.13     Test space adjustment speed:approximately 150mm/min;
3.17     Host weight (kg): 1500
3.17     External dimensions of the host mm:850× 650 ×1800
3.18     External dimensions of oil source mm:1100×700×930
3.19     Net weight of the host :1500kg

4. System Configuration Checklist

4.1     Testing machine main engine：oil cylinder, bottom mounted main engine     1 set
4.2     High precision load sensor：Wide range spoke sensor                      1 set  
4.3     Integrated oil source control cabinet：Italian Mazucci oil pump                  1 set  
4.4     Electrohydraulic servo valve： Domestic proportional servo valve                   1 set
4.5     Servo control system：Yingbaixin proprietary technology production            1 set         
4.6     Electric control system ：Yingbaixin proprietary technology production            1 set
4.7     Extensometer (optional accessory) with a gauge：Distance of 50mm and a deformation of 10mm (Place of origin: Changchun, Ningbo, or Sichuan)       1 unit
4.8     Optoelectronic encoder:Domestic                                 1 set
4.9     Computer host: Commercial brand computer                                       1 set
4.10     Accessories    
                Round specimen tensile jaws mm ：Φ 13- Φ 26 ，Φ 26- Φ 40      1 set each
                Flat sample tensile pliers mm：0-15                        1 set
                Compression attachment mm    ： φ 120                      1 set
4.11     Random tools                                                       1 set