Paper number 501
ACOUSTIC EMISSION IN LAMINATED BEAMS DUE TO FIBER FRACTURES |
Mats Åberg and Peter Gudmundson
Department of Solid Mechanics, Royal Institute of Technology, KTH
100 44 Stockholm, Sweden
Summary | A model for excitation and propagation of waves resulting from fiber fracture in laminated beams is presented. The fiber fracture was described as a time dependent displace-ment discontinuity and wave propagation was modeled by a higher order beam theory. The equations of motion defined by the beam model were then formally solved by employing integral transforms. Asymptotically valid solutions were subsequently found using residue calcu-lus and the stationary phase method. In particular displacement velocities at different points in a [90/0 2 /90] beam with a width to thickness ratio of 10 is presented. Based on the results it is concluded that fiber fracture excites several modes of vibration in the specimen, also a criterion for validity range, in frequency, of beam models is suggested. |
Keywords | wave propagation, fiber fracture, acoustic emission, laminated beams. |