THE ANALYSIS OF VIBRATION CHARACTERISTIC OF COMBINATION FOUNDATION WITH COMPOSITE MATERIAL AND STEEL

摘要

The vibration of ship power equipment is one of the main sources of the ship hull vibration, as an important part of vibration transfer media, the characteristics of the foundation directly affect the performance of vibration isolation in the whole ship. Under the condition of strength and stiffness non-decrease, part of typical steel foundation structure are instead by composite plate. Vibration characteristic of steel foundation and combined foundation made of steel and composites were analyzed. Based on the evaluation index of modal, impedance and vibration acceleration level, the influence on vibration characteristics of structure with different composite layer angles were studied under same support steel structure. Results show that vibration acceleration level of support structure of composites-steel foundation are lower than that of steel foundation under the same load. Thus, the natural frequency of composites-steel foundation could be changed by reasonable design. Based on the effect of lay angle on foundation's modal, impedance and vibration acceleration level, lay angles could be divided into three patterns, namely, 0°, 5° to 60° and 90°.