300 / 500 / 1000 / 3000 kN Computer Control Electro-Hydraulic Servo Fatigue Testing Machine

The DST series is a computer control electro-hydraulic servo dynamic and static universal testing machine offered from 300 kN to 3000 kN. It is used for the mechanical fatigue testing of a wide range of materials, including low-carbon steel and titanium alloys and other metal materials, and carbon fibre, glass fibre and other non-metallic materials and composites. It also carries out tensile-compression-bending fatigue tests on building materials, such as steel bar tension, concrete compression and rock and soil block compression.

Because the machine is servo-hydraulic, the same frame applies a static force for a conventional test and a dynamic, cyclic force for a fatigue test, with the actuator driven by a servo valve from a hydraulic oil source. The computer control system generates the test waveform, holds the mean load and amplitude, counts the cycles and stops the test at the programmed conditions.

Technical Specifications

Dynamic and static testing in one frame

The DST series is a dynamic and static machine: the same hydraulic actuator that applies a slow static force for a proof or tensile test also applies a cyclic force for a fatigue test, so a laboratory does not need one machine for static work and a second for dynamic work. The actuator is a double-rod, double-acting cylinder, which gives a symmetrical force in tension and compression and keeps the moving mass balanced. The standard actuator amplitude is ±75 mm, with ±100 mm and ±150 mm available, and the actual stroke is more than twice the amplitude so that the waveform is not clipped at the ends of the travel.

The test force accuracy is ±1.0% or ±0.5% over the test range from ±2% to 100% of full scale, and the displacement accuracy is ±0.5% FS. Those figures apply to both the static and the dynamic mode, so a fatigue test and a static verification test on the same machine are quoted on the same basis.

Choosing the capacity and the test conditions

The series spans ±300 kN through ±3000 kN across six models, so the frame is matched to the specimen and to the intended load rather than to a single headline figure. The smaller frames, DST2305 and DST2505, reach higher frequencies – from 0.001 Hz up to 25 Hz, or 0.1 Hz to 60 Hz in the optional configuration – which suits small, stiff specimens that can be cycled quickly. The larger frames, from DST2106 to DST2306, run from 0.001 Hz to 15 Hz, or 0.1 Hz to 30 Hz in the optional configuration, which is appropriate for heavier specimens where the oil flow limits the achievable speed.

Test waveforms include sine, triangle, square and ramp waves, and user-defined waveforms such as pulse, half-sine and half-triangle can be customised. Fixtures can be mechanical tension, compression and bending grips or hydraulic chucks, and optional accessories include a high and low temperature environmental box, a high temperature furnace and a confining pressure box for rock and soil testing.

Frame, oil source and customisation

The frames are built with widths between columns of 700 x 500 mm, 850 x 500 mm or 900 x 700 mm and test space heights of 1500 mm (600 mm) or 2000 mm (600 mm), so that a specimen and its furnace or environmental chamber fit within the load train. Overall dimensions run from 1100 x 900 x 2600 mm to 1600 x 1400 x 3250 mm. The recommended oil source capacities are 36, 45, 70, 90 or 150 L/min at a preset pressure of 21 MPa, selected to match the actuator area and the required frequency and amplitude.

The machine is offered as a customisable platform: the amplitude and structure of the actuator, the test space and the oil source (including a high-efficiency or silent type) can be tailored to the application, so a customer with an unusual specimen or an existing test rig can have the frame dimensioned around it.

Frequently Asked Questions

What capacities does the DST series cover?
The series ranges from ±300 kN to ±3000 kN across the models DST2305, DST2505, DST2106, DST2156, DST2206 and DST2306.

Can the machine do both static and fatigue tests?
Yes. It is a dynamic and static universal testing machine, so the same servo-hydraulic actuator applies slow static forces and cyclic fatigue forces.

What is the test force and displacement accuracy?
Test force accuracy is ±1.0% or ±0.5% over the test range ±2% to 100% FS, and displacement accuracy is ±0.5% FS.

What waveforms and frequencies are available?
Sine, triangle, square and ramp waves are standard and user-defined waveforms such as pulse or half-sine can be customised; frequencies range from 0.001 Hz to 25 Hz (or 0.1-60 Hz) on the smaller models and 0.001 Hz to 15 Hz (or 0.1-30 Hz) on the larger models.

Can the machine be customised?
Yes. The actuator amplitude and structure, the test space and the oil source (including a silent or high-efficiency type) can all be customised to the application.

Related Products & Pages

• Fatigue Testing Machines
• Hydraulic Universal Testing Machines
• 300/600/1000 kN WAW-B Series Computerized Hydraulic Universal Testing Machine
• Metal Testing

About CHENJI & Support

CHENJI is the brand of Jinan Chenji International Trade Co., Ltd. (Shandong, China), a manufacturer and exporter of material testing machines since 2014, with in-house quality control plus third-party inspection by SGS or Bureau Veritas. The company holds ISO 9001 certification (626024QH073R1) and is a Bureau Veritas audited supplier (MIC-ASR2451820). Testing machines are normally supplied with a calibration certificate valid for 12 months and traceable to national force standards, and our engineers help you select the machine, fixtures and accessories for your specimen and method.

Every quotation is prepared against the standard you test to, so the delivered machine matches the test method rather than only the headline capacity. Spare parts, consumables and calibration support are available after delivery, and machines can be produced to OEM or ODM requirements when a customer drawing or specification is provided.

Selecting and Verifying a Testing Machine

Choosing a machine is a matter of matching capacity to the specimen and the method, not of buying the largest frame. A 1000 kN machine is not suitable for a sample that needs 1 N of force; capacity selection follows the specimen and the standard, and the force measuring system should be verified per ISO 7500-1 or ASTM E4 on a regular schedule. Load cells are commonly supplied as class 0.5 or class 1, which means the indicated force stays within ±0.5% or ±1% of the true force.

Test results are only comparable when they are quoted together with the standard, the specimen geometry, the test speed and the force measurement class. We are glad to review your test method and specimen so that the machine, fixtures and accessories are correctly specified before you order.

Request a Quotation

Tell CHENJI the specimen, the maximum load, the frequency and the waveform you need, and we will match the DST series model, the actuator, the fixtures and the oil source for a quotation.

Email annie@chenjitester.com or call / WhatsApp +86 158 5311 1612.