A Study on Flexural Properties of Sandwich Structures with Fiber/Metal Laminate Face Sheets S. Dariushi & M. Sadighi Received: 6 September 2012 / Accepted: 27 November 2012 / Published online: 23 January 2013 # Springer Science+Business Media Dordrecht 2012 Abstract In this work, a new family of sandwich structures with fiber metal laminate (FML) faces is investigated. FMLs have benefits over both metal and fiber reinforced composites. To investigate the bending properties of sandwich beams with FML faces and compare with similar sandwich beams with fibrous composite faces, 6 groups of specimen with different layer arrangements were made and tested. Results show that FML faces have good resistance against transverse local loads and minimize stress concentration and local deformations of skin and core under the loading tip. In addition, FML faces have a good integrity even after plateau region of foam cores and prevent from catastrophic failures, which cannot be seen in fibrous composite faces. Also, FML faces are lighter than metal faces and have better connection with foam cores. Sandwich beams with FML faces have a larger elastic region because of simultaneous deformation of top and bottom faces and larger failure strain thanks to good durability of FMLs. A geometrical nonlinear classical theory is used to predict force-deflection behavior. In this model an explicit formula between sym- metrical sandwich beams deflections and applied force which can be useful for designers, is derived. Good agreement is obtained between the analytical predictions and experimental results. Also, analytical results are compared with small deformation solution in a parametric study, and the effects of geometric parameters on difference between linear and nonlinear results are discussed. Keywords Sandwich structures . Fiber metal laminates . Flexural properties . Large deformation . Parametric study 1 Introduction A sandwich structure consists of two basic constituents, the faces and the core. Face sheets typically made from metal sheets or fibrous composite layers, both have some advantages and disadvantages. Searching for new materials with better properties is in progress [1, 2]. Appl Compos Mater (2013) 20:839–855 DOI 10.1007/s10443-012-9307-2 S. Dariushi : M. Sadighi (*) Mechanical Engineering Department, Amirkabir University of Technology, Tehran, Iran e-mail: Mojtaba@aut.ac.ir