A common way of softening the material properties is to apply an empirical coefficient to the measured values. This leads to a simplistic understanding of the real effects on the part, especially when it comes to failure prediction. To overcome this limitation of isotropic simulation data, the scope of measurement needs to be expanded. DOMO’s MMI material data is based on specially designed specimens cut out of plates at defined locations. This allows a detailed look at the influence of the glass-fiber orientation on the mechanical properties.
Mechanical material models: How is data measured and how are material models built?
Material data for all relevant use-cases is needed. For each polyamide material, this includes different temperatures, different humidity levels and, where needed, the influence of time-based effects like low strain-rate creep and high strain-rate crash data. In addition, cyclic fatigue loads or even material aging need to be assessed.
Surely, not all imaginable material use-case conditions can be measured in a realistic time frame with realistic efforts. Thus, a design-of-experiments (DOE) controlled strategy is needed to optimize the time to create a complete database. At DOMO, this DOE approach is enhanced using a polymer science-based multi-scale meta-model approach.
DOMO’s way of building high quality data:
- DOE controlled in-house measurements to build response surfaced-based models
- Video-extensometer-based true stress/true strain tests allow an optimal material model calibration
- Constant local strain rates during the tests whatever the kind of loading applied
- Specimen shape is optimized to ensure maximum quality of the strain measurement
- Unique dedicated test benches for high-speed testing, creep testing, climatic testing, and more
- Exhaustive tomography measurements for glass fiber micro-structure characterization (for reverse engineering)
- Advanced methods based on first principal and polymer physics
Experimental results are translated into material models to make them usable for different applications in various environmental conditions. See material model section to learn more.
DOMO provides anisotropic mechanical models for more than 70 TECHNYL® grades, including three recycled TECHNYL®4EARTH® grades.