The evaluation and quantification of fracture strength in manufacturing can pose several challenges. Listed below are some examples:
- Material properties can be surprisingly variable in many categories, even within the same production batch. As production volumes increase, it’s common for materials to become commoditized, and this can induce a new kind of variability that can be hidden.
- The size and geometry of test samples can dramatically influence fracture strength test results. For example, small samples often will not accurately represent the behavior of larger parts, with consequent discrepancies between test data and real-world performance. Complex geometry can impose stress concentrations or make test results impossible to interpret.
- Fracture strength varies considerablyaccording to loading conditions. Determining a loading condition that realistically reflects the application can be challenging.
- Environmental factors such as temperature, humidity, and chemical exposure affect fracture strength. Testing fracture strength under controlled environmental conditions can be challenging and requires highly specialized equipment, rendering this approach a lower-frequency test, in most cases.
- Strain rate dependency can be a major factor that skews test results. Some materials exhibit rate-dependent fracture properties, whereby the fracture strength can vary significantly at different loading rates.
