Location effects of passive damping material in croos-ply laminates on nautal frequency and mode shape

摘要

This study presents an experimental investigation of the free vibration of cantilevered composite laminated plates with embedded passive damping material at different stages. A total of five composite laminated pates are considered. The lay-up sequences for the five composite laminated plates are considered. The lay-up seuences for the five composite laminated plates with and without two embedded layers of passive damping material are [90 deg /0 deg /90 deg /0 deg ]_s, [90 deg /0 deg /90 deg /0 deg /d/0 deg ]_s, [90 deg /0 deg /d/90 deg /0 deg ]_x, and [90 deg /d/0 deg /90 deg /0 deg ]_s. The passive damping material employed is a 3M material, SJ-2015 ISD 112, with peak damping proerties inthe ampient temperature range of 32 deg F to 140 deg F. The composite material used is a carbon fiber (997-2)/epoxy resin(IM7). The effect of the passive damping system employed in this study for the composite plates aer discussed. Modal testing is performed on these plates to determine resonant frequencies, amplitude and mode shape information. The study included whilte noise and sinusoidal dynamic testing techniques, a PC computer based data acquisition system, and a virtual instument dynamic anslysis.