SM-104 | Fatigue Testing Machine

Moving components and machine parts are often exposed to periodically fluctuating loads. Even if the dynamic load is far below the static load capacity, this load can lead to fracture of the component after a long time because of material fatigue. The fatigue strength and design strength of components are determined in fatigue strength tests or endurance tests. The clean layout and simple operation mean the experimental sequence can be observed in all details and phases. In the experiment, a fixed-fixed or cantilever-mounted and rotating cylindrical specimen is subjected to a single force. The load on the specimen corresponds to a cantilever bending beam. The specimen is subjected to a pure reverse bending stress and breaks after a certain number of load cycles because of material fatigue. The load amplitude can be addition of weights. An electronic counter registers the number of load cycles and displays it digitally. The impulse for the counter is provided by an inductive proximity switch on the motor coupling. The counter can also be used to measure the speed. A protective cover protects against flying fragments. By using this apparatus system for data acquisition, the measured values can be transferred to a PC where they can by analysed with the software.

Learning Objectives

• Fatigue strength of bars under reverse bending stress
• Influence of different fillet radii and surface qualities on the fatigue strength