scholarly journals Equivalent Model Utilizing Finite Element Method on Coupling Between Beam-Type and Oval-Type Vibrations of a Cylindrical Water Storage Tank

2008 ◽  
Vol 74 (737) ◽  
pp. 8-15
Author(s):  
Akira MAEKAWA ◽  
Michiaki SUZUKI ◽  
Katsuhisa FUJITA
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Storage Tank ◽  
Water Storage ◽  
Equivalent Model ◽  
Water Storage Tank ◽  
Beam Type ◽  
Element Method

scholarly journals Analysis of nodalization effects on the prediction error of generalized finite element method used for dynamic modeling of hot water storage tank

2015 ◽  
Vol 36 (3) ◽  
pp. 123-138 ◽  
Author(s):  
Marcin Wołowicz ◽  
Jakub Kupecki ◽  
Katarzyna Wawryniuk ◽  
Jarosław Milewski ◽  
Konrad Motyliński
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Flow Rate ◽  
Prediction Error ◽  
Storage Tank ◽  
Water Storage ◽  
Hot Water ◽  
Generalized Finite Element Method ◽  
Water Storage Tank ◽  
Generalized Finite Element

Abstract The paper presents dynamic model of hot water storage tank. The literature review has been made. Analysis of effects of nodalization on the prediction error of generalized finite element method (GFEM) is provided. The model takes into account eleven various parameters, such as: flue gases volumetric flow rate to the spiral, inlet water temperature, outlet water flow rate, etc. Boiler is also described by sizing parameters, nozzle parameters and heat loss including ambient temperature. The model has been validated on existing data. Adequate laboratory experiments were provided. The comparison between 1-, 5-, 10- and 50-zone boiler is presented. Comparison between experiment and simulations for different zone numbers of the boiler model is presented on the plots. The reason of differences between experiment and simulation is explained.

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

2017 ◽  
Author(s):  
Hongliang Gou ◽  
ZiDuan Shang ◽  
Yugang Sun ◽  
Meng Chu ◽  
Honghui Ge
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Storage Tank ◽  
Water Storage ◽  
Element Model ◽  
Equivalent Model ◽  
Water Storage Tank ◽  
Structure Interaction

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.

A numerical approach based on finite element method for the wrinkling analysis of dielectric elastomer membranes

2021 ◽  
pp. 1-37
Author(s):  
Guoyong Mao ◽  
Wei Hong ◽  
Martin Kaltenbrunner ◽  
Shaoxing Qu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Thickness Distribution ◽  
Numerical Approach ◽  
Dielectric Elastomer ◽  
Equivalent Model ◽  
Maxwell Stress ◽  
Buckling Mode ◽  
Post Buckling ◽  
Element Method

Abstract Dielectric elastomer (DE) actuators are deformable capacitors capable of a muscle-like actuation when charged. When subjected to voltage, DE membranes coated with compliant electrodes may form wrinkles due to the Maxwell stress. Here, we develop a numerical approach based on the finite element method (FEM) to predict the morphology of wrinkled DE membranes mounted on a rigid frame. The approach includes two steps, I) pre-buckling and II) post-buckling. In step I, the first buckling mode of the DE membrane is investigated by substituting the Maxwell stress with thermal stress in the built-in function of the FEM platform SIMULIA Abaqus. In step II, we use this first buckling mode as an artificial geometric imperfection to conduct the post-buckling analysis. For this purpose, we develop an equivalent model to simulate the mechanical behavior of DEs. Based on our approach, the thickness distribution and the thinnest site of the wrinkled DE membranes subjected to voltage are investigated. The simulations reveal that the crests/troughs of the wrinkles are the thinnest sites around the center of the membrane and corroborate these findings experimentally. Finally, we successfully predict the wrinkles of DE membranes mounted on an isosceles right triangle frame with various sizes of wrinkles generated simultaneously. These results shed light on the fundamental understanding of wrinkled dielectric elastomers but may also trigger new applications such as programmable wrinkles for optical devices or their prevention in DE actuators.

An Equivalent Constitutive Model of Cancellous Bone With Fracture Prediction

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Mohammad Salem ◽  
Lindsey Westover ◽  
Samer Adeeb ◽  
Kajsa Duke
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cast Iron ◽  
Constitutive Model ◽  
Cancellous Bone ◽  
Equivalent Model ◽  
Plasticity Model ◽  
Microscale Model ◽  
Computational Resources ◽  
Element Method

Abstract To simulate the mechanical and fracture behaviors of cancellous bone in three anatomical directions and to develop an equivalent constitutive model. Microscale extended finite element method (XFEM) models of a cancellous specimen were developed with mechanical behaviors in three anatomical directions. An appropriate abaqus macroscale model replicated the behavior observed in the microscale models. The parameters were defined based on the intermediate bone material properties in the anatomical directions and assigned to an equivalent nonporous specimen of the same size. The equivalent model capability was analyzed by comparing the micro- and macromodels. The hysteresis graphs of the microscale model show that the modulus is the same in loading and unloading; similar to the metal plasticity models. The strength and failure strains in each anatomical direction are higher in compression than in tension. The microscale models exhibited an orthotropic behavior. Appropriate parameters of the cast iron plasticity model were chosen to generate macroscale models that are capable of replicating the observed microscale behavior of cancellous bone. Cancellous bone is an orthotropic material that can be simulated using a cast iron plasticity model. This model is capable of replicating the microscale behavior in finite element (FE) analysis simulations without the need for individual trabecula, leading to a reduction in computational resources without sacrificing model accuracy. Also, XFEM of cancellous bone compared to traditional finite element method proves to be a valuable tool to predict and model the fractures in the bone specimen.

An equivalent model for sandwich panel with double-directional trapezoidal corrugated core

2019 ◽  
Vol 22 (7) ◽  
pp. 2445-2465
Author(s):  
Huimin Li ◽  
Lei Ge ◽  
Baosheng Liu ◽  
Haoran Su ◽  
Tianyi Feng ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Elastic Modulus ◽  
Sandwich Panel ◽  
Equivalent Model ◽  
Geometrical Parameters ◽  
Detailed Model ◽  
Novel Structure ◽  
Homogeneous Method ◽  
Element Method

A novel sandwich panel with double-directional corrugated core is proposed in this paper. This complex-corrugated core makes the conventional detailed finite element analysis of large structures a tough work. Thus, an equivalent homogeneous method is proposed, the key of which is to obtain the equivalent property of this novel structure. The equivalent elastic modulus considering the effect of geometrical parameters is analytically derived and verified by finite element method. Besides, equivalent shear modulus and Poisson’s ratios are obtained by finite element method. Three-dimensional detailed and equivalent models are established for further validation of this equivalent homogeneous method. Results show that elastic modulus predicted by analytical formulas is in good agreement with that by finite element method no matter how geometrical parameters change. It has been proved that stretching deformation is dominating in thickness direction, and only corrugation along loading direction can bear the load. The proposed novel sandwich structure owns better mechanical property than the conventional one with single-corrugated core. The result by equivalent model agrees well with that by detailed model, which means that this equivalent homogeneous method can well predict the macroscopic property of this novel structure.

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