Quasi-isotropic fiber metal laminate with high specific modulus and near-zero coefficient of thermal expansion

Abstract

On the basis of lamination theory, a quasi-isotropic fiber metal laminate (FML) with a near-zero coefficient of thermal expansion (CTE) and high specific modulus was designed, using pitch-based carbon fiber reinforced plastic (CFRP) prepreg and stainless steel (SST). The SST to CFRP thickness ratio was determined so that the laminates had an exact-zero CTE at room temperature (25 °C). The CTE of a fabricated FML was accurately measured using embedded fiber Bragg grating (FBG) sensors, to verify that the CTE had a near-zero value around room temperature. The temperature dependence of the FML CTE from 20 to 120 °C was investigated via finite element analysis (FEA) taking the temperature-dependent material properties into account. It was demonstrated from the experiment and FEA that the present FML had a near-zero CTE around room temperature (20–45 °C) and a higher Young's modulus and specific modulus compared with other relevant materials.

Keywords

• Coefficient of thermal expansion
• Quasi-isotropic
• Specific modulus
• Fiber metal laminate
• FBG sensor