In materials science, fatigue is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. The maximum stress values are less than the ultimate tensile stress limit, and may be below the yield stress limit of the material.

As part of the engineering design process engineers have to assess not only how well the design satisfies the performance requirements but also how durable the product will be over its life cycle. A major cause of failure is the growth of cracks which grow due to fatigue loadings to the the point where the critical component/part fails. In aging aircraft and aging infrastructure in particular, structural components are being utilized far past their design life. Having a solution

DMI’s Fatigue Monitoring (FM) system is a portable, handheld, battery powered instrument that measures a material's strain state using a semi-permanent wire free gage. FM reveals strain anomalies, differentials, and trends over time, which may indicate possible fatigue damage, the onset of cracking, and/or other material-health issues. Each FM gage delivers multiple, simultaneous, non-linear strain readings by simply placing the FM handheld 'reader' over the gage. FM gages are used on metals, composites, plastics, and more. As a self-contained strain measurement system, FM eliminates equipment and labor costs associated with conventional strain measurement, and offers unmatched measurement capabilities plus powerful data display and logging features. Additionally, each gage has a unique identification code which allows for time domain data analysis and comparison during future maintenance cycles.

DMI’s FM solution consists of hand held reader, a ruggedized tablet PC and DMI FM gages. Each gage has it’s own unique identification number and is a precision laser-machined geometric pattern on an adhesion treated polymer backing. Each gage is capable of making multiple strain differential measurements with the gage area. The reader includes DMI’s patented and patent pending software and unique optic reading process for accurate and quick data retrieval.

• Scientifically proven measurement system
• Can be utilized as conjunction with visual inspections
• Field and maintainer friendly
• Each gage provides a unique identification location for future data analysis and comparison during routine maintenance cycles
• Data can be integrated into Finite Elements Models (FEM) for improved new product development