Matrix cracking in transverse layers of cross-ply beams subjected to bending and its effect on vibration frequencies

The solution for the matrix crack distribution in transverse layers of a cr oss-ply beam subjected to bending is developed based on the model of Han an d Hahn (Compos Sci Technol 35 (1989) 377). This solution accounts for a bim odulus-type of the material response. As a result, it is possible to predic t the extent and distribution of matrix cracks as well as the stiffness dis tribution in the beam subjected to bending, accounting for residual thermal stresses. The results of the solution of the bending problem are employed in the analysis of free and forced vibrations of a cross-ply beam with matr ix cracks in transverse layers. The solution differs from the case of vibra tions of an intact beam due to a difference in response of damaged layers u nder tension and compression. The results are shown for the natural frequen cy of a representative ceramic matrix composite (CMC) beam. (C) 2001 Elsevi er Science Ltd. Ail rights reserved.