High Fidelity Testing and Control
There is an old adage in the research community: "Your data is only as good as the system used to collect it." In our case, we need highly precise data collection capabilities to enable our unique slow-rising stress intensity testing. For example, to control a test by stress intensity, you need to have a precise measurement of crack length, otherwise your command will be incorrect. To achieve this difficult measurement, the Environmental Cracking Lab has developed expertise in utilizing direct current potential difference (dcPD) to evaluate crack lengths with 0.5 micron accuracy. We use Fracture Technology Associates's (FTA) software to automate these calculations and send the required commands to the MTS Station Manager software which then communicates with the load frame itself. A second factor that must be accounted for, especially when fatigue testing specimens, is crack closure. Thankfully, FTA's software also allows us to attack this by either the ASTM 2% Offset or the ACR method. All in all, the combination of FTA and MTS allows us to exert extensive control over our testing, thereby ensuring high fidelity data collection and accurate results.
As stated above, we often test our specimens using slow-rising stress intensity, but we can also use slow-rising displacement when needed. We also have the capability to conduct standard fatigue testing, tensile testing, and other typical fracture mechanics experiments.
