Optimization of Additively Manufactured Sandwich Panels with Composite Face Sheets

Abstract

Sandwich structures are of great interest to researchers all around the world for their flexural stiffness, strength-to-weight ratio, and high energy absorption. These structures are extensively used in the aerospace, naval, and automotive industries. In this work, we describe a novel method to make monolithic sandwich panels with fiber-reinforced face sheets using a DLP 3D printer. The method was tuned to achieve high fidelity parts with accurate dimensions. For example, the amount of photo absorber was adjusted and found to be essential in achieving high print resolution. Samples with and without fiber-reinforced face sheets were printed using two different core geometries, honeycomb and rectangular, and printed in two different orientations, in-plane and out-of-plane. The specific stiffness of each of these four sample categories was then analyzed via 3-Point-Bending tests. In both reinforced and non-reinforced sandwich panels, the honeycomb structure showed the highest stiffness-to-weight ratio for out-of-plane orientation, while the rectangular structure showed the highest stiffness-to-weight ratio for in-plane orientation. Reinforced samples had a specific stiffness that was 130% and 240% more than that of non-reinforced samples in out-of-plane and in-plane samples, respectively.%%%%M.S., Chemical Engineering – Drexel University, 2020