Rotating Beam Fatigue Test System
Specialized Torsion System for Rotating Beam Testing
How it Works
Rotating beam fatigue testers are one of the oldest methods used to determine a materials fatigue behavior. To perform a test with ADMETs Rotating Beam Tester, a sample is placed in the machine and a force is applied via a bending moment using weights hung off the sample. The force induces a surface stress that will be tensile on one side of the sample and compressive on the opposite side. When the test is started, the sample will rotate at the desired rate and this rotation will cause the surfaces to interchange so that each surface experiences alternating tensile and compressive stresses. The sample is left in the machine until failure at which point ADMETs eP2 controller will display the number of cycles it took for the sample to fail. Running a series of tests on identical samples with varying stresses will allow the user to create an S-N curve.
Please watch our video for a demonstration of ADMETs Rotating Beam Fatigue System equipped with eP2 controller.
Key Terms
S-N Diagram for steel, fiber-reinforced plastic, and aluminum
Rotating beam fatigue testing systems were first developed in the mid-1800s by a German railroad engineer named August Wöhler. He designed the machine to test railroad car axles and investigate axle brake failures. The principles upon which that machine was developed still apply today.
Wohlers Fatigue Testing Machine
Wohlers S-N curves for Krupp axle steel
Rotary Bending Fatigue Testing
The Advanced Materials Research Laboratory is home to three R.R. Moore rotary fatigue testing machines located in the mechanical testing laboratory.
The machine design is based on the rotating beam principle. The specimen functions as a simple beam symmetrically loaded at two points. When rotated one half revolution, the stresses in the specimen originally below the neutral axis are reversed from tension to compression and vice versa. Upon completing the revolution, the stresses are again reversed so that during one revolution, the test specimen passes through a complete cycle of flexural stresses .
Servo Hydraulic Fatigue Test Machines Grips And Test Fixtures
Raagen has a big engineer team for designing of different test fixtures according to various test standards.This team analyse the customer’s exact requirement of required tests. They offer correct fixture types and dimensions for customer.Raagen offers different kind of tensile test fixtures, compression test plates, flexural and bending test apparatus, shear test fixtures, peeling tests fixtures, eccentric rollers, chucks, puncture test fixtures, specimen cutters and cutting dies. See more…
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Rotating Beam Fatigue Test Method
It is estimated that over 90% of material failures in service are caused by fatigue and not simply mechanical overloading. The execution of metals fatigue testing to calculate a materials endurance limit is critical in many industries like aerospace and automotive to ensure safe, efficient, and long-lasting product designs.The primary method to determine a metals endurance limit would be through Force Controlled Constant Amplitude Axial Fatigue Testing per ASTM E466 or ISO 1099. These test methods are well-regarded and performed at many materials testing labs around the world.
Rotating Beam Fatigue testing has been around since the 1800s. It enables researchers to:
- Perform fatigue testing at higher frequencies, often up to 100Hz, leading to faster actionable data compared to axial fatigue testing.
- Save capital expenses by purchasing a much simpler and more cost-effective test machine design compared to high capacity servo-hydraulic axial fatigue test systems. Rotating beam fatigue machines often cost in the range of 20%-25% of an axial fatigue machine rated for metals testing, and dont require as much upkeep.
Rotating Beam Fatigue Testing Application of Force
In rotating beam fatigue testing applications, a bending stress is applied to a round specimen in constant rotation, causing the surfaces of the specimen see alternating tensile and compressive stresses. This method effectively mimics an axial fatigue test with an R value of -1.
Rotary Bending Testing Machines
Rotating bar bending fatigue tests at various types of specimens with high measurement accuracy and comfortable operation
Rotary bending testing machine are designed for dynamic fatigue tests by Wöhler according to DIN 50113 at specimens like wire, round specimens and rods as well as appropriate components, such as camshafts. Rotary bending testing machines are used in quality and material control.
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Features Of Raagen Rotational Bending Fatigue Testing Machines
– Standard models with current capacity have a force capacity of 300N, 500N, 1000N, 3000N.
– The system can be configured according to user needs.
– It is fully automatic and controlled by computer software.
– Machine rotation and force application are made by means of precision servo motors. Standard models up to 3000 rpm are available, and fatigue systems are designed specifically for the project by Raagen engineers for systems that will operate at higher speeds.
– It has a compact table unit design that provides easy installation and easy use in laboratories.
– Grips that can be adjusted according to the samples, a sliding system that can be adjusted according to the sample lengths, and a transparent protective cover for safety are included in the basic package content of our standard devices.
Digital Fatigue Testing Machines
We are Manufacturer, Supplier, Exporter of Digital Fatigue Testing Machines and our set up is situated in Sangli, Maharashtra, India.
This machine is light, compact and simple design used to test the fatigue strength of materials and draw S-N diagram used for research institutes, laboratories, material manufacturers and various industries. Table model, no need of foundation. This is a rotating beam type machine in which load is applied in reversed bending fashion. The standard 8 mm dia specimen is held in special holders at its ends and loaded such that it experiences a uniform bending moment. The specimen is rotated at 4200 rpm by a motor. A complete cycle of reversed stresses in all fibres of the specimen is produced during each revolution. The bending moment is applied with a lever system and can be easily changed by moving a weight over the lever. Total number of revolutions at which the specimen fails are recorded by a Digital counter. An interlocking system puts off the motor at specimen failure. Machine meets requirements of IS 5075-1969.
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