FLUID-FILLED STRUCTURE WITH MULTIPLE COMPOSITE COMPARTMENTS SUBJECTED TO LOW-VELOCITY IMPACT

Abstract

The focus of this study was to investigate the dynamic response and the fluid-structure interaction (FSI) in a fluid-filled composite structure with multiple compartments subjected to a low-velocity impact. The compartments were used to simulate multiple structures separated by a fluid medium. The design apparatus was fabricated from Polymethly Methacrylate (PMMA) plastic components and carbon fiber sheets with varying thicknesses. The structure was struck with a low-velocity impact from a spherical object attached to a pendulum and the oscillatory motion of the fluid within the container was analyzed. The design structure was filled at multiple water levels to study the impact of the added mass and fluid coupling effects that are attributed to the amount of water in the structure and the distance between the plates. The measurable quantities are the impact force, the strain gauges attached to the carbon fiber sheets and the natural frequency of the fluid within the structure. The results showed that the FSI and the dynamic response was significantly increased due to the rise in water fill level and that the resonance frequency of the structure decreased with an increase in water level. The distance between structures was also significant but not as predictable as the fill level and must be monitored closely in future designs using experimental testing during the design process.