Test unit for high-cycle compression and bending fatigue tests

• Subject Area: Construction Engineering and Architecture
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 569320302

The fatigue of materials and structural components at very high numbers of load cycles has been insufficiently examined up to now, since the associated testing effort is considerable. Although test data are available on material specimens with higher numbers of load cycles, the number of structural component tests performed worldwide is still limited. Due to the complexity of material behavior under fatigue loading, it is extremely difficult to draw conclusions about the real behavior of a large component from the behavior of individual material specimens or scaled-down models. The Institute of Concrete Structures at the TU Dresden is therefore planning to procure a high-performance testing machine for high-cycle fatigue tests on structural components and material specimens. Cyclic tests on large components with spans up to 4.0 m are planned, as well as cyclic compression tests on normal to ultra-high performance concrete specimens of various sizes. The specimens are to be tested at frequencies up to 20 Hz with a maximum piston oscillation width of 3.1 mm and up to 100 million load cycles (VHCF range). The capacity of the testing machine is 4,000 kN for static testing and 3,000 kN for cyclic testing. The hydraulic cylinder can be driven either servo-hydraulically or by a pulsator. The tests generate significant vibrations that must not be emitted into the environment. Therefore, the large test unit consists of a rigid 4-column load frame including the differential test cylinder. The stand is rigidly connected to an active vibration-isolated solid base. The load frame, the machine base and the active spring-damper bearings under the base thus form a mass-spring-damper system isolated from the environment. The test unit also includes a pulsator that can help reduce energy consumption during fatigue testing by up to 90%. In addition, the test unit includes a climatic chamber that can be moved into the load frame on rails. The research in the field of fatigue of materials and structural components planned with this large-scale facility is intended to improve the currently inadequate transferability of laboratory results from small-scale fatigue tests to real component situations, thus closing a significant gap in research.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Prüfeinheit für hochzyklische Druck- und Biegeversuche
• Instrumentation Group: 2910 Dynamische Prüfmaschinen und -anlagen, Pulser
• Applicant Institution: Technische Universität Dresden
• Leader: Professor Dr.-Ing. Steffen Marx