Issue 47

V. Rizov, Frattura ed Integrità Strutturale, (2047) 468-481; DOI: 10.3221/IGF-ESIS.47.37 468 Influence of material inhomogeneity and non-linear mechanical behavior of the material on delamination in multilayered beams Victor Rizov Department of Technical Mechanics, University of Architecture, Civil Engineering and Geodesy, 1 Chr. Smirnensky blvd., 1046 – Sofia, Bulgaria V_RIZOV_FHE@UACG.BG A BSTRACT . The delamination fracture in four-point bending beams made of adhesively bonded lengthwise vertical layers is studied assuming that each layer exhibits smooth material inhomogeneity along the width and length of the layer. The study aims at determining the strain energy release rate with applying the Ramberg-Osgood equation for modeling the non-linear mechanical behavior of the material in each layer. Cosine laws are used to describe the continuous variation of the modulus of elasticity in width and length directions of layers. Beams made of an arbitrary number of vertical layers which have individual widths and material properties are considered. Besides, the delamination crack is located arbitrary between layers, i.e. the two crack arms have different widths. The J -integral is applied for verification of the non-linear solution to the strain energy release rate derived in the present paper. The solution is used to investigate the influence of material inhomogeneity in width and length directions of layers, the crack location along the beam width, the non-linear mechanical behavior of the material and the crack length on the delamination fracture behavior. The approach developed is expected to be useful in structural design of multilayered inhomogeneous beams with considering the delamination fracture behavior. K EYWORDS . Multilayered beam; Material inhomogeneity; Delamination fracture; Non-linear mechanical behavior of the material. Citation: Rizov, V., Influence of material inhomogeneity and non-linear mechanical behavior of the material on delamination in multilayered beams, Frattura ed Integrità Strutturale, 47 (2019) 468-481. Received: 31.10.2018 Accepted: 17.12.2018 Published: 01.01.2019 Copyright: © 2017 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION tructural members and components made of adhesively bonded layers of dissimilar materials are extensively used in various applications in aerospace and civil engineering mainly when high performance is required [1-3]. Various studies of adhesively bonded joints of fiber reinforced composites and sandwich structures have been reviewed in [1]. The influence of different factors such as joint configuration, adhesive properties, preparation of surfaces and environment factors on the joint behavior has been evaluated and discussed thoroughly. Methods and approaches for predicting the failure behavior have been presented too. The application of fracture mechanics for analyzing of adhesively S