Fracture Mechanics

The challenge of fracture mechanics studies

The study of the fracture mechanics of materials is one of the most interesting and exciting fields in materials testing. This field measures under what conditions a crack initiates and its resistance to crack growth as a function of the applied load or environmental conditions.

Fracture mechanics is important to such wide-ranging applications as advanced materials for micro-electro-mechanical systems applications, solid rocket propellants, aluminum or steel for aircraft or structural support applications, and even asphalt for roads. Quantitative evaluation can also provide information for basic material selection, or the evaluation of defects introduced during the manufacturing process.

The growing need for new materials for new applications

The wide variety of engineered materials that are currently being considered for cyclic load-bearing applications requires a substantial amount of new test data. Specifically, fatigue and fracture testing is needed for a broader array of materials over a wider range of conditions than ever before.

Such tests enable prediction whether engineered materials such as nanocomposites can replace traditional metals for dynamic load-bearing applications.  In addition, smaller test specimens such as foils, fibers, and films, and even small devices such as micro-electromechanical devices, create unique testing requirements. To test such materials and components, ElectroForce test instruments, using high performance linear moving-magnet motors, are replacing traditional servo-hydraulic, electro-mechanical, or voice coil technologies used in fatigue and fracture test equipment.

The equipment required for fracture mechanics evaluation can be quite complex, including high frequency cyclic capabilities to reduce test time, very accurate control of test conditions to ensure data validity, aggressive environments for evaluating material-environment interaction, advanced sensor technologies for determining the compliance of the sample or the crack length directly, and extremely reliable test equipment for trouble-free high cycle testing.