In recent times, composites have rapidly replaced metals in aerospace structures due to their advances in weight reduction, thereby increasing component strength. With that, it can be expected that the need to periodically measure service strains on these materials will increase correspondingly. This is because the composites undergo a change in their mechanical, thermal, and chemical properties as a result of their changing directions, unlike metallic materials. These materials have differing stiffness properties in different directions. For this reason, cyclic load testing is performed on aircraft structures to generate fatigue life and crack growth data, identify critical locations and demonstrate the safety of a structure that may be susceptible to fatigue.
Strain gauges are employed for determining the durability and damage tolerance of a structure using fatigue testing. As this type of testing is generally performed in high stress, the DSF Series high endurance strain gauge from TML is recommended. This strain gauge is remarkably durable compared to conventional strain gauges as it offers a fatigue life over 10 million times at a strain level of ±3000×10-6 strain.
The DSF series strain gauges greatly reduce the time and cost of adhering gauges. However, it is necessary to use a new strain gauge frequently as soon as a gauge reaches its fatigue life. Also, depending on the operating temperature, a suitable lead wire can be selected to attach the strain gauge.