The impact of BCC lattice structure on low-pressure turbine blade structural dynamics

In this study, a Body-Centered Cubic (BCC) lattice structure is integrated into a low-pressure turbine (LPT) high-lift profile (T106C) blade to evaluate the enhancement in the structural dynamics under both Unit and Aerodynamic loading conditions. This is demonstrated numerically and experimentally by cost-effective turbine blade prototyping, using Polylactic Acid (PLA). Five PLA blade models (Solid, Hollow, and three BCC location-based designs) are numerically analyzed for mass and natural frequencies, from which two blades (Hollow and BCC blade with the best location combination) are selected for experimental validation. Furthermore, vibrational response characteristics (displacement, acceleration, and stress) of these selected blades are evaluated at their resonating frequencies and compared. The BCC blade design showed that it is 33.2% lighter than the solid blade while enhancing the natural frequencies by 16.4% and 8.6%. Compared to the Hollow blade, the BCC reduced the acceleration by 9%, displacement by 24%, and overall equivalent (von Mises) stress by a factor of two.