Response of CFRPAAC Sandwich Structures under Low- Velocity Impact

Abstract

The low velocity impact response of plain autoclaved aerated concrete (AAC) and carbon fiber reinforced polymer (CFRP)AAC sandwich panels has been investigated. The structural sandwich panels composed of CFRPAAC combinations have shown excel¬lent characteristics in terms of high strength and high stiffness-to-weight ratios. In addition to having adequate flexural and shear properties, the behavior of CFRPAAC sandwich panels needs to be investigated when subjected to impact loading. During service, the structural members in building structures are subject to impact loading that varies from object-caused impacts, blasts due to explosions, and high-velocity impact of debris during tornadoes, hurricanes, and storms. Low-velocity impact (LVI) testing serves as a means to quantify the allowable impact energy the structure can withstand, and to assess the typical failure modes encountered during this type of loading. The objectives of this paper are: to study the response of plain AAC and CFRPAAC sandwich structures to low-velocity impact and to assess the damage performance of the panels; to study the effect of CFRP laminates on the impact response of CFRPAAC panels; and to study the effect of the processing method (hand lay-up versus vacuum assisted resin transfer molding) and panels’ stiffness on the impact response of hybrid panels. Impact testing was conducted using an Instron drop-tower testing machine. Experimental results showed a significant influence of CFRP laminates on energy absorption and peak loads of CFRPAAC panels. A theoretical analysis was conducted to predict the energy absorbed by CFRPAAC sandwich panels using the energy balance model. Results found were in good accordance with the experimental data.