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Abstract

In this paper, large amplitude thermally induced vibration (TIV) of annular and circular plates is analyzed under cooling shocks. A novel comparison of the TIV response is presented under rapid cooling and heating shock loads. This is the first time that TIV study has been presented for any flexural structure under thermal cooling. Structures can experience cooling shock loads in many circumstances, for example when exposed to spills of cryogenic liquids. The functionally graded composite plates are made of 304 grade stainless steel (SUS 304) and low-carbon steel (AISI 1020) and are graded through the plate thickness to have a continuously varying spatial composition profile in thickness direction. Thermo-mechanical properties are assumed to be temperature dependent. The plates are modeled using first-order shear deformation theory with von Karman geometric nonlinearity. The Generalized Differential Quadrature Method (GDQM) and Newton-Raphson technique are employed to solve the governing equations. A Fourier heat equation is used to evaluate temperature distribution over time using GDQM and Crank-Nicolson approaches. The validation study is conducted based on the literature and FEM software ABAQUS. Detailed parametric study is presented focusing on the effect of thermal shock magnitude, rapidity of the thermal shock application, plate geometry, material distribution, geometrical nonlinearity and temperature dependency of material properties. Differences in the response due to these factors have been shown between cooling and heating thermal loads. Results show that importance of the inertia effect is substantially higher under sudden cooling than it is under sudden heating, for the same thermal load magnitude and rapidity of thermal shock. Moreover, it is shown that stresses induced by thermal cooling can potentially reach yield strength of the material with relatively large amplitudes of fluctuations. Therefore, to estimate realistically the structural behavior of thin/slender plates under rapid cooling, the inertia effect should be taken into the account and TIV analysis needs to be performed.