Design and multi-objective optimization of CFRP electric spindle bracket

Abstract

To address the high mass and limited dynamic performance of traditional metal electric spindle supports, this paper proposes a structural design and multi-objective optimization method for a carbon fiber reinforced polymer (CFRP) support. First, static and modal finite element analyses are performed on a HT300 gray cast iron support to obtain its stiffness, natural frequency, and relative frequency deviation as benchmarks. Then, metal-CFRP hybrid structures based on 3D weaving and 3D braiding are designed, and their finite element models are analyzed for static and dynamic performance. Using static stiffness, relative frequency deviation, and mass as optimization objectives, five structural parameters are selected as design variables. A polynomial response surface surrogate model is constructed via Latin hypercube design, and multi-objective optimization is conducted using the NSGA-II algorithm. The optimal CFRP support achieves a 90.35% increase in static stiffness, a 40.41% reduction in mass, and a 68.74% increase in relative frequency deviation compared to the metal support, validating the effectiveness of the proposed method.