Advisor(s)
Brian Pillay
Committee Member(s)
Haibin Ning
Vinoy Thomas
Document Type
Thesis
Date of Award
6-18-2026
Degree Name
Master of Science (MS)
School
School of Engineering
Department
Materials Engineering
Abstract
Composite sandwich structures, consisting of two stiff face sheets separated by a lightweight core, are widely used in engineering applications because of their high strength-to-weight ratio, energy absorption capability, and thermal and acoustic insulation properties. Conventional manufacturing methods typically involve pre-fabricating the core material, such as foam or honeycomb, and subsequently bonding it to the face sheets using adhesives or resin infusion processes. However, these approaches often require large storage space for pre-formed core materials, specialized bonding equipment, multiple processing steps, and significant transportation space for the final structures, which can increase manufacturing costs and introduce logistical challenges. To address these limitations, this study investigates an alternative manufacturing approach based on an in-situ foam casting technique for producing foam-core composite sandwich panels. In this method, liquid polyurethane (PU) foam is cast between two prefabricated face sheets, where it expands and cures in place, simultaneously forming the structural core and the bonding layer between the skins. Because the foam acts as both the core and adhesive, understanding the skin–core interfacial characteristics is essential, as the interface affects the overall mechanical performance of sandwich structures. In this work, foam-core-based sandwich panels were fabricated using the foam casting method. For comparison, another set of panels was produced using a conventional fabrication method. Three different foam core densities were investigated to evaluate their influence on interfacial bonding and mechanical performance. The skin–core interface was examined through microstructural analysis, and the mechanical behavior of the panels was evaluated using flatwise tensile, flexural, and edgewise compression tests. The results of the flatwise tensile and flexural tests showed similar trends. At low foam core density, the traditional method exhibited higher strength compared to the foam casting method. At intermediate foam density, the traditional method still showed slightly higher strength, although the difference became smaller. At higher foam density, the foam casting method demonstrated higher strength than the traditional method. The results of the edgewise compression test indicated that the foam casting method exhibited higher strength than the traditional method for all foam core densities. These findings suggest that the foam casting method is a promising fabrication technique for sandwich structures, as it can simplify the manufacturing process while maintaining competitive mechanical performance.
Keywords
Composite sandwich panels;Foam density;In-situ foam casting;Mechanical properties;Polyurethane foam;Skin–core interface
ProQuest ID
Recommended Citation
Alhaday, Laila, "Mechanical Behaviors Of Polyurethane Foam Core-Based Composite Sandwich Panels Using In-Situ Foam Casting" (2026). ETDs from 2020-2029. 216.
https://digitalcommons.library.uab.edu/etd-2020s/216
