Semnan University Press Mechanics of Advanced Composite Structures 2423-4826 6 1 2019 04 01 Propagation of Matrix Cracking and Induced Delaminatin in Cross-Ply Composite Beams Subjected to Bending Loads 45 50 3791 10.22075/macs.2019.16711.1186 EN Mohammad Bahrami Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran Amin Farrokhabadi Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran Journal Article 2018 12 09 Due to the mismatch of mechanical properties in composite laminates, propagation of delami-nation is considered as a severe damage mechanism in beams with various lay-up configurations. Delamination can be generated due to matrix cracking propagation or it can also be initiated due to the manufacturing process before using composite beams. Using a micromechanics model, this study is aimed to investigate the bending moment required for matrix cracking and induced delamination in cross-ply composite beams. To that end, a unit cell is selected from the lamina surface in a composite beam containing matrix cracking and delamination. Later, the governing equation of stress and displacement fields are extracted in the unit cell to calculate the strain energy release rate due to the propagation of matrix cracking and induced delamination.  In order to validate this method, the stiffness variations in Carbon-Epoxy cross-ply laminate [90/0₂]s is examined and the obtained results are compared with the numerical results. It concluded that there is a favorable agreement between the results of the proposed micromechanics model and available numerical results. https://macs.semnan.ac.ir/article_3791_690bb330e5e7e3e07867fafc4d32ec82.pdf