Sandwich structures are general-purpose structures that can reduce the structural weight of composite ships. Core materials are essential for these structures, with polyvinyl chloride (PVC) foams being the most popular. These foam core materials are subjected to various tests in the development process, and must satisfy the performance requirements of several ISO and ASTM standards. Therefore, a procedure for evaluating the performance of foam core materials was proposed in this paper. In addition, prototypes were fabricated using a commercial PVC foam core product in accordance with the structural design of an 11 m fiber-reinforced plastic yacht. Then, a case study was conducted on the proposed evaluation procedure. The proposed procedure facilitates the understanding of the performance requirements and evaluation of core materials used in composite ships and is expected to be utilized in developing core materials for marine structures.

Abstract
1. Introduction
2. Test and Evaluation Procedures for FoamCore Materials used in Marine Structures
    2.1 Foam core material density for the design of sandwichstructures
    2.2 Requirements of foam core materials suitable forthe marine environment
    2.3 Structural requirements of foam core materialsapplied to sandwich structures
3. Application of Test and Evaluation Procedures
    3.1 Selection of the foam core material and fabricationof sandwich structures
    3.2 Evaluation of foam core materials
    3.3 Evaluation of sandwich structures with PVC foam
4. Conclusion
References

• Jae-Won Jang(Graduate School, Mokpo National Maritime University)
• Sookhyun Jeong(Graduate School, Mokpo National Maritime University)
• Daekyun Oh(Department of Naval Architecture and Ocean Engineering, Mokpo National Maritime University)
• Je-Hyoung Cho(Research Institute of Medium & Small Shipbuilding)
• Jackyou Noh(Department of Naval Architecture & Ocean Engineering Kunsan National University) Corresponding Author