Structural Health Monitoring
Under Structural Health Monitoring (SHM) the continuous or periodic and automated method is meant for determining and monitoring the state of a monitoring object in the monitoring state (according to DIN ISO 17359). This is done through measurements with permanently installed or integrated sensors and through analysis of the measurement data. Damage, for example cracks or deformations, should be detected at an early stage so that countermeasures can be initiated.
An SHM system consists of both a monitoring object with measuring sensors, signal adjustment units and data memories as well as the data processing system and the automated diagnosis system. The state of the monitored object can be determined in various levels of detail. This can include the current recording of the stress (e.g. as a result of an acting load or environmental influences), damage detection, the determination of the type of damage up to the assessment of the effects (integrity of the monitored object, stability and load-bearing capacity). Monitoring objects are primarily structures with load-bearing properties and / or often statically supported structures such as rotor blades of wind turbines or the support or hull surfaces of ships and aircraft, pipelines, containers, vehicles (automobiles, rail vehicles) and rails, high-voltage lines, foundation structures of offshore structures , Bridges, structures.
While SHM is used for static components, condition monitoring relates to the monitoring of machines. A model example for both methods is the human skin, the pain receptors of which provide spatially resolved and timely information about both the physical stress and the state of health.
Procedure
Components are usually tested after specified times. The inspection intervals must be chosen so that damage can be identified before a total failure occurs.
The SHM method delivers characteristic values at any time that provide information on whether or not damage has occurred. With this finding alone, airlines expect up to 40 percent savings in maintenance times . In the second step, the location and size of the damage should be determined in order to be able to make a statement in the third step as to what influence the damage has on the properties of the structure and whether the component does not have to be replaced immediately.
SHM applications are found for example in bridges, in the air and space travel , in wind power plants and pipelines . Attempts are being made to embed glass fibers, so-called Fiber Bragg sensors, in wings and rotor blades. Changes in the light signals that are sent through the fibers provide information about the load on the components. Alternatively, ultrasound methods are being investigated.
See also
Individual evidence
- ↑ according to DGZfP technical committee for condition monitoring: http://www.dgzfp.de/Fachaussch%C3%BCsse/Zustands%C3%BCberendung