Seismic Performance of PCS Water Storage Tank Considering Fluid-Structure Interaction

Author(s):  
Hongliang Gou ◽  
ZiDuan Shang ◽  
Yugang Sun ◽  
Meng Chu ◽  
Honghui Ge

Water sloshing of PCS water storage tank (PCSWST) can cause a significant effect on the dynamic response of Shield Building under seismic loads. It is complicated to perform the calculation of water sloshing especially for the tanks with irregular shapes. Consequently, it is important to establish an appropriate equivalent mechanical model for simulation[1], [2]. In this paper, the water sloshing is firstly investigated based on the potential flow theory, which including the seismic modal analysis. Based on the theoretical research, a highly efficient (simplified) calculation formula is derived, which mainly considering the impulse mass, convective mass, position function and spring stiffness etc., through this way the equivalent model for PCSWST is established by applying mass-spring element. The equivalent models based on Housner & Graham theory[3], [4] are also established. Additionally, the 3-D finite element model of water sloshing considering fluid-structure interaction is established by using the software of Ansys. Total of four models are built as shown in the paper, then modal analysis and dynamic response under earthquake excitation are performed using ANSYS. The results are compared to justify the equivalent model in this paper. The results indicate that Graham formula did not provide the correct location expressions for the convective masses. The expressions for the impulsive mass and its position given by Housner are not satisfactory. As a comparison, the results from the equivalent model, which is recommended in this paper, can best fit the data from finite model. From above results and comparisons, a more reasonable and refined equivalent model for PCSWST design is provided. Based on the equivalent model established, the influence on structure caused by the increase of water mass is analyzed. The results from the seismic analysis are compared, including member force, shear strain and shear force. Based on the research, the feasibility of the design is analyzed, which can provide important support for the structural design. Finally, the seismic reduction of water tank is studied using the finite element model established in this paper. The horizontal and vertical anti-sloshing baffles are designed. The maximum acceleration and displacement corresponding to different baffle length are compared to study the effect of the seismic reduction.

2012 ◽  
Vol 479-481 ◽  
pp. 1809-1812
Author(s):  
Jiang Gui Han ◽  
Mei Qian

The effect of vibration reduction is analyzed for viscoelastic damping layer of gearbox device. A viscoelastic material is added to the internal and external wall of the gearbox’s oil-pan. A finite element model is established, meanwhile the modal analysis, the dynamic response and structure noise is calculated. The influence of vibration performance by damped vibration reduction technology in the application of gear system provide scientific theory basis.


Author(s):  
Hauke Herrnring ◽  
Søren Ehlers

Abstract This paper presents a finite element model for the simulation of ice-structure interaction problems, which are dominated by crushing. The failure mode of ice depends significantly on the strain rate. At low strain rates the ice behaves ductile, whereas at high strain rates ice reacts in brittle mode. This paper focuses on the brittle mode, which is the dominating mode for ship-ice interactions. A multitude of numerical approaches for the simulation of ice can be found in the literature. Nevertheless, the literature approaches do not seem suitable for the simulation of continuous ice-structure interaction processes at low and high confinement ratios in brittle mode. Therefore, this paper seeks to simulate the ice-structure interaction with the finite element method (FEM). The objective of the here introduced Mohr-Coulomb Nodal Split (MCNS) model is to represent the essential material behavior of ice in an efficient formulation. To preserve mass and energy as much as possible, the node splitting technique is applied, instead of the frequently used element erosion technique. The intention of the presented model is not to reproduce individual cracks with high accuracy, because this is not possible with a reasonable element size, due to the large number of crack fronts forming during the ice-structure interaction process. To validate the findings of the model, the simulated maximum ice forces and contact pressures are compared with ice-extrusion and double pendulum tests. During validation, the MCNS model shows a very good agreement with these experimental values.


2014 ◽  
Vol 900 ◽  
pp. 742-745 ◽  
Author(s):  
Yao Jie He ◽  
Bai Jing Qiu ◽  
Ya Fei Yang

In order to attenuate the deformation of spray boom, a finite element model built based on ANSYS, according to the reasults of numerical modal analysis and modal texting, the reliability of the finite element model was affirmed. Then, an isolator was introduced between spray boom and frame, a frame-isolator-spray boom model was built in ADAMS. The effect of the isolators which have different parameters was research, the reasult shows: The isolator has much effect on attenuating spray booms deformation, the stiffness of isolators spring dampers has little effect on spray booms deformation, but the damping of isolators spring dampers has effect on spray booms deformation.


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