Dynamic properties of structures integrated with tuned liquid sloshing dampers analyses

• Main Author: Gospel, Jessica Vania
• Other Authors: Ivan Au
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Structural dynamics; Tuned liquid sloshing dampers; Dynamic properties; Single degree of freedom; Multiple degree of freedom; Free vibration; Forced vibration; Housner formula; Fast fourier transform
• Online Access: https://hdl.handle.net/10356/177490
• Institution: Nanyang Technological University

The literature review explores the dynamic behaviour of Single Degree of Freedom (SDOF) systems under free vibration. SDOF systems are crucial in mechanical and structural engineering for understanding dynamic behaviour. Free vibration, a fundamental concept, occurs when a system oscillates freely from its equilibrium position, driven solely by its initial conditions and inherent properties. Natural frequencies and mode shapes govern free vibration dynamics, offering insights into a system's behaviour. Analytical frameworks, including Newton's laws and energy principles, form the basis for understanding free vibration phenomena. Theoretical formulations lead to mathematical models, facilitating the derivation of exact solutions for displacement, velocity, and acceleration as functions of time. Log decrement cycle counting emerges as a method for estimating damping ratios in vibrating systems, particularly useful for damped sinusoidal signals. Fast Fourier Transform (FFT) provides a means to analyse frequency content, decomposing signals into frequency components. FFT aids in identifying dominant frequencies, crucial in modal analysis for determining natural frequencies and mode shapes. Spectral analysis techniques like Power Spectral Density (PSD) further enhance signal processing capabilities, describing power distribution across frequencies. Additionally, the review delves into SDOF systems under forced vibration, exploring the dynamic response to external forces or excitations. Resonance phenomena and frequency response characteristics are discussed, highlighting the influence of damping mechanisms on system behaviour. The discussion extends to Multiple Degree of Freedom (MDOF) systems under free vibration, emphasizing the complexity introduced by additional degrees of freedom. The mechanism and derivation of Tuned Liquid Sloshing Dampers (TLSD) are explored, focusing on wave behaviour opposing structural excitation to provide additional damping. Linear theory and modifications thereof are discussed for predicting sloshing motion, considering impulsive and convective components. Finally, the Sloshing Frequency Formula by Housner is presented, offering a means to determine natural frequencies in sloshing fluids.