What does the top 3 parameters that affect the drift of a reinforced concrete building with viscous dampers?5 answersThe top 3 parameters that significantly affect the drift of a reinforced concrete building with viscous dampers are the damping coefficient, relative velocity, and relative velocity coefficient. These parameters play a crucial role in determining the capacity of viscous dampers to reduce earthquake energy in structures. Additionally, the seismic performance of buildings with viscous dampers is influenced by factors such as building height, seismic zone, and placement of dampers. Furthermore, the response modification factor, which is a key seismic design parameter, is higher for reinforced concrete structures equipped with viscous damper devices compared to those without, with the number of damper devices and building height significantly impacting these factors.
Can the addition of friction dampers reduce building acceleration due to earthquakes?5 answersThe addition of friction dampers can indeed reduce building acceleration during earthquakes. Research has shown that friction dampers placed at strategic locations within a building can effectively dissipate seismic energy, thereby reducing the building's response to earthquakes. Studies have demonstrated that friction dampers, such as those designed for reinforced concrete frame structures, existing building frames, high-rise buildings, and precast structures, have been successful in decreasing interlayer displacement angles, limiting lateral deformation, controlling structural accelerations, and minimizing stress results. These dampers have proven to be effective in reducing peak displacements, floor shear forces, and overall seismic response, showcasing their ability to mitigate building acceleration during seismic events.
How does visco-thermal affect sound absorption?4 answersVisco-thermal effects play a significant role in sound absorption. The absorption properties of porous materials can be accurately estimated by modeling the thermal and viscous boundary layers through boundary conditions to the Helmholtz equation for acoustic pressure. In the case of an omnidirectional acoustic absorber, the viscothermal losses of the structure, consisting of an absorbing core and a surrounding gradient-index lens, contribute to about 90% of the total energy dissipated in the core. Acoustic metasurfaces designed using Helmholtz resonators also take into account the effect of fluid viscosity on acoustic energy dissipation, resulting in near-perfect absorption at specific frequencies. Additionally, visco-thermal effects are necessary to realistically describe the acoustic response of metamaterials, as they can completely avoid the excitation of resonances and lead to 100% reflection in certain cases.
What is the problem Statement of cost optimisation and carbon Emissions in RC building retrofitted by Viscous problem?4 answersCost optimization and carbon emissions in RC building retrofitted by viscous problem is a problem statement that involves finding ways to minimize costs and reduce carbon emissions in the retrofitting of reinforced concrete (RC) buildings using a viscous problem-solving approach. The problem statement aims to address the challenges of optimizing the use of resources and materials while also mitigating the environmental impact of the retrofitting process. It recognizes the need to balance economic considerations with sustainability goals in order to achieve cost-effective and environmentally-friendly solutions for RC building retrofits.
What are the advantages and disadvantages of using viscous dampers to protect a building structure from corrosion?5 answersViscous dampers have several advantages for protecting building structures. They are effective in enhancing the seismic performance of existing structures, allowing for the maximum utilization of energy dissipation capacity and leading to a more effective and economical design approach. Viscous dampers can improve the seismic performance of structures with significant energy loss, produce out-of-phase damping force relative to displacement, and increase structural damping without major changes in stiffness characteristics. They can also reduce the amount of seismic input force to the structure, decrease floor drift, and increase energy absorption and performance in the structure. However, there are no specific mentions of using viscous dampers to protect a building structure from corrosion in the provided abstracts.
How can viscous dampers be modeled in ETABS?3 answersViscous dampers can be modeled in ETABS by implementing a viscous damping model in the dynamic free-surface boundary condition. The model takes into account the damping induced by flow separation and wall friction through two damping coefficients: the local loss coefficient and the friction loss coefficient. The local loss coefficient is determined through physical model tests, while the friction loss coefficient is estimated using an empirical formula from the literature. This viscous damping model has been successfully applied to simulate wave-induced fluid responses in narrow gaps and moonpools, capturing both resonant amplitude and frequency under various damping conditions. Additionally, accurate mapping of dynamic viscosity is crucial for constructing viscous dampers, and a new method based on the three-parameter Weibull function has been proposed to approximate the dynamic viscosity of poly(dimethylsiloxane).