Lattice Structure and Strut Thickness Optimization for Turbine Blade Modal Parameters

This article explores the utilization of simple-cubic, diamond, octet-truss, and X-type lattice structures for low-pressure turbine blades in engine turbines to enhance natural frequency and decrease overall engine weight while maintaining structural integrity. The research method involves analyzing polylactic acid (PLA) hollow T106C blades with fully infilled and 50–80 location-based lattice arrangements. The study modifies the strut thickness of lattice structures using both constant and variable-based approaches and applies a generalized formula based on relative density to evaluate how changes in lattice thickness and arrangements influence natural frequencies. Furthermore, the investigation extends to multi-lattice configurations, introducing a parameter 𝑘 to signify the transition between different lattices. The modified blades were 3D printed using PLA and tested for natural frequencies through modal testing. The results demonstrate that location-based 50–80 exponential-based lattice structures combining octet-truss and X-type lattices yield the best performance, achieving a 15% increase in the first mode and 14.6% in the second mode when compared to hollow blade. In comparison, fully infilled 50–80 exponential-based lattice structures with a combination of octet-truss and X-type lattices achieve a 9.4% increase in the first mode and 12.7% in the second mode. These findings highlight that lattice structures can effectively improve natural frequencies across all modes.