Linear and nonlinear 2-D finite element analysis of sloshing modes and pressures in rectangular tanks subject to horizontal harmonic motions

JUAN C. VIRELLA; CARLOS A. PRATO; LUIS A. GODOY

JOURNAL OF SOUND AND VIBRATION

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Oxford; Año: 2008 vol. 312 p. 442 - 460

0022-460X

The influence of non-linear wave theory on the sloshing natural periods and their modal pressure distributions are investigated for rectangular tanks under the assumption of two dimensional behavior. Natural periods and mode shapes are computed and compared for both linear wave theory (LWT) and non-linear wave theory (NLWT) models, using the finite element package ABAQUS. LWT is implemented in an acoustic model, whereas a plane strain problem with large displacements is used in NLWT. Pressure distributions acting on the tank walls are obtained for the first three sloshing modes using both LWT and NLWT. It is found that the non-linearity does not have significant effects on the natural sloshing periods. For the sloshing pressures on the tank walls, different distributions were found using LWT and NLWT models. However, in all cases studied, the LWT conservatively estimated the magnitude of the pressure distribution, whereas larger pressures resultant heights were obtained for NLWT. It is concluded that the non-linearity of the surface wave does not have major effects in the pressure distribution on the walls for rectangular tanks.