Thermoelastic properties of sandwich materials with pin-reinforced foam cores

• 来源期刊: 中国科学E辑（英文版）
• 年，卷（期）: 2008,（12）
• 页码范围: 2059-2074
• 页数: 16页
• 语种: 英文
• DOI: 10.1007/s 11431-008-0226-2

摘要

Pin-reinforced foam is a novel type of sandwich core materials formed by inserting pins (trusses) into a foam matrix to create a truss-like network reinforced foam core. Upon loading, the pins deform predominantly by local stretching whilst the defor-mation of foam is governed by local bending. This paper presents a theoretical study on the thermoelasllcity of pin-reinforced foam sandwich cores. To calculate the effective thermoelastic properties of pin-reinforced foam cores, the energy-based homogenization approach is employed to develop a micromechanics-based model, calibrated by the existing experimental data. It is found that the stiffness of the sandwich core is mainly governed by pin reinforcements: the foam matrix con-tributes little to sandwich stiffness. Compared with traditional foam cores without pin reinforcements, the changes in in-plane thermal expansion coefficients are not vigorous as a result of pin reinforcements, while the through-thickness thermal expansion coefficient changes significantly. It is also demonstrated that it is pos-sible to design materials with zerO or negative thermal expansion coefficients un-der such a context.