Damping Ratio Measurement through Modal Analysis of Smart Hybrid Nanocomposite Internal Damper to Absorb Critical Energy in Concrete Structures
Abstract
Viscoelastic materials offer damping and energy absorption capabilities. The brittle nature of cementitious composites makes them vulnerable to damage. One practical way to solve the problem is to incorporate filler materials in the form of nanomaterials into the concrete. When structures are subjected to resonance under vibrations, they encounter large amplitudes that ultimately result in the structure failing. This research examines the energy absorption capacity of concrete materials that contain nano-silicon dioxide (SiO2) and graphene using experimental methods such as cantilever-free vibration. Using an accelerometer sensor, modal analysis was performed on the produced cement composite damper beams using a cantilever-type free-vibration test rig. Nano-SiO2 and Graphene, when introduced, lead to secondary hydration, and new interfaces between the existing and new hydration products are produced. More damping is produced by increasing the non-uniform stress distribution and expanding the total interfaces, as studied by microstructural analysis. According to trial experiments, a nano-SiO2 percentage of 2.0% gave the best damping effects. The damping ratio obtained by this quantity of nano-SiO2 gives a damping ratio of 13.5 %, which is 8% more than the damping ratio of normal concrete. The combination of nanomaterials improves interfaces, enhances concrete's capacity to reduce frictional energy consumption, and thereby increases the overall damping properties.