Hydrodynamic response analysis of a 10,000-ton offshore electrical platform in waves using a modified finite element model

2021 ◽  
Vol 233 ◽  
pp. 109194
Author(s):  
Sheng-Xiao Zhao ◽  
Chun-Wei Bi ◽  
Dong-Liang Zhang ◽  
Hua-Feng Yu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Response Analysis ◽  
Hydrodynamic Response

scholarly journals Design optimization of vehicle asynchronous motors based on fractional harmonic response analysis

2021 ◽  
Vol 12 (1) ◽  
pp. 689-700
Author(s):  
Ao Lei ◽  
Chuan-Xue Song ◽  
Yu-Long Lei ◽  
Yao Fu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Natural Frequency ◽  
Asynchronous Motor ◽  
Element Model ◽  
Design Parameters ◽  
Response Analysis ◽  
Harmonic Response ◽  
First Order ◽  
Harmonic Response Analysis

Abstract. To make vehicles more reliable and efficient, many researchers have tried to improve the rotor performance. Although certain achievements have been made, the previous finite element model did not reflect the historical process of the motor rotor well, and the rigidity and mass in rotor optimization are less discussed together. This paper firstly introduces fractional order into a finite element model to conduct the harmonic response analysis. Then, we propose an optimal design framework of a rotor. In the framework, objective functions of rigidity and mass are defined, and the relationship between high rigidity and the first-order frequency is discussed. In order to find the optimal values, an accelerated optimization method based on response surface (ARSO) is proposed to find the suitable design parameters of rigidity and mass. Because the higher rigidity can be transformed into the first-order natural frequency by objective function, this paper analyzes the first-order frequency and mass of a motor rotor in the experiment. The results proved that not only is the fractional model effective, but also the ARSO can optimize the rotor structure. The first-order natural frequency of asynchronous motor rotor is increased by 11.2 %, and the mass is reduced by 13.8 %, which can realize high stiffness and light mass of asynchronous motor rotors.

Frequency Window Implementation of Adaptive Multi-Level Substructuring

1998 ◽  
Vol 120 (2) ◽  
pp. 409-418 ◽  
Author(s):  
J. K. Bennighof ◽  
M. F. Kaplan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Center Frequency ◽  
Response Analysis ◽  
Adaptive Procedure ◽  
Multi Level ◽  
Frequency Window ◽  
Efficient Representation ◽  
Multiple Levels

Adaptive multi-level substructuring (AMLS) is a method for reducing the order of a complex structure’s finite element model by orders of magnitude, while ensuring that the accuracy available from the original model is preserved. A structure’s finite element model is transformed to a much more efficient representation in terms of approximate vibration modes for substructures on multiple levels. An adaptive procedure constructs an optimal model for satisfying a user-specified error tolerance, by determining which modes should be included in the model. In this paper, a frequency window implementation of AMLS is developed, in which frequency response analysis can be done over a frequency window at little additional cost beyond that of the center frequency solution. A numerical example is presented.

scholarly journals Analysis of Stationary Random Responses for Non-Parametric Probabilistic Systems

2010 ◽  
Vol 17 (3) ◽  
pp. 305-315 ◽  
Author(s):  
Y. Zhao ◽  
Y.H. Zhang ◽  
J.H. Lin ◽  
W.P. Howson ◽  
F.W. Williams
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Physical Structure ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Random Matrix Model ◽  
Stiffness Matrices ◽  
Element Technique ◽  
Non Parametric

The move from conceptual design, through fabrication to observation and measurement on the resulting physical structure is fraught with uncertainty. This, together with the necessary simplifications inherent when using the finite element technique, makes the development of a predictive model for the physical structure sufficiently approximate that the use of random structural models is often to be preferred. In this paper, the random uncertainties of the mass, damping and stiffness matrices in a finite element model are replaced by random matrices, and a highly efficient pseudo excitation method for the dynamic response analysis of non-parametric probability systems subjected to stationary random loads is developed. A numerical example shows that the dynamic responses calculated using a conventional (mean) finite element model may be quite different from those based on a random matrix model. For precise fabrication, the uncertainties of models cannot be ignored and the proposed method should be useful in the analysis of such problems.

Frequency Window Implementation of Adaptive Multi-Level Substructuring

1995 ◽  
Author(s):  
Jeffrey K. Bennighof ◽  
Matthew F. Kaplan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Center Frequency ◽  
Response Analysis ◽  
Adaptive Procedure ◽  
Multi Level ◽  
Frequency Window ◽  
Efficient Representation ◽  
Multiple Levels

Abstract Adaptive multi-level substructuring (AMLS) is a method for reducing the order of models of complex structures by orders of magnitude, while ensuring that the accuracy available from the original finite element model is preserved. A structure’s finite element model is transformed to a much more efficient representation in terms of approximate vibration modes for substructures on multiple levels. An adaptive procedure constructs an optimal model for satisfying a user-specified error tolerance, by determining which modes should be included in the model. In this paper, a frequency window implementation of AMLS is developed, in which frequency response analysis can be done over a frequency window at little additional cost beyond that of the solution at the center frequency. A numerical example is presented.

A Parametric Study for the Seismic Response Analysis of a Nuclear Reactor Building by Using a Three-Dimensional Finite Element Model

2016 ◽  
Author(s):  
Byunghyun Choi ◽  
Akemi Nishida ◽  
Norihiro Nakajima
Keyword(s):  
Finite Element ◽  
Research And Development ◽  
Finite Element Model ◽  
Seismic Response ◽  
Parametric Study ◽  
Three Dimensional ◽  
Element Model ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
Uncertainty Parameters

Research and development of three-dimensional vibration simulation technologies for nuclear facilities is one mission of the Center for Computational Science and e-Systems of the Japan Atomic Energy Agency (JAEA). A seismic intensity of upper 5 was observed in the area of High-Temperature Engineering Test Reactor (HTTR) at the Oarai Research and Development Center of JAEA during the 2011 Tohoku earthquake. In this paper, we report a seismic response analysis of this earthquake using three-dimensional models of the HTTR building. We performed a parametric study by using uncertainty parameters. Furthermore, we examined the variation in the response result for the uncertainty parameters to create a valid 3D finite element model.

Analysis of Crankshaft Fatigue Strength Based on Integrated Finite Element Model

2010 ◽  
Vol 44-47 ◽  
pp. 1558-1562 ◽  
Author(s):  
Xiao Ping Chen ◽  
Ru Fu Hu ◽  
Shu Hua Zheng
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Fatigue Limit ◽  
Limit Load ◽  
Element Model ◽  
Response Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Complex Mechanical Systems ◽  
Multi Body

Aiming at the complex mechanical systems for the prediction of the fatigue limit load requirements, this paper examines the relationship among finite element analysis model and the performance models. And a finite element modeling method for fatigue analysis is proposed. The finite element model can support static, modal, fatigue, and multi-body dynamic response analysis in parallel and collaboration. This method helps improve the fatigue limit load analysis.

Analysis of Dynamic Characteristic of Numerical Remanufacture Machine's Feeding System

2010 ◽  
Vol 156-157 ◽  
pp. 1360-1365
Author(s):  
Qiu Lin Pu ◽  
Xiao Diao Huang ◽  
Wen Zheng Ding
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Operating Conditions ◽  
Ball Screw ◽  
Response Analysis ◽  
Feeding System ◽  
Nature Frequency ◽  
Grinding Machine ◽  
The Finite Element Model

In this paper,the ball screw feeding system’s dynamic characteristics of a numerical remanufacture grinding machine is analyzed using the FEM. Discusses the modeling method of ball screw system into the finite element model and established the combination of finite element model. Through the modal analysis and the harmonious response analysis, the nature frequency and vibration mode of the feeding system and typical operating conditions of excitation in the harmonic responsehave have been gotten,thus the dependable basis for the construction’s optimization and dynamic function’s increasing of the feeding system is provided, ensure the numerical remanufacture will be success.

scholarly journals Rocking response of liquid-filled cylindrical tanks

2021 ◽  
pp. 875529302098197
Author(s):  
Faizan Ul Haq Mir ◽  
Ching-Ching Yu ◽  
Andrew S. Whittaker
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Analytical Solutions ◽  
Element Model ◽  
Seismic Input ◽  
Rotational Components ◽  
Hydrodynamic Response ◽  
Cylindrical Tanks ◽  
Angular Displacements ◽  
The Finite Element Model

The hydrodynamic response of liquid-filled storage tanks subjected to translational earthquake shaking has been the focus of studies for more than 75 years. In service, tanks experience six components of seismic input, with rocking due to support flexibility and/or rotational components of ground motion. Published theory for predicting hydrodynamic responses in rigid cylindrical tanks due to rotational seismic input is examined. Analytical solutions for pressure in the fluid and on the tank wall, and base moment are modified to account for the effects of angular displacements at the base. A finite element model of a water-filled cylindrical tank using the Arbitrary Lagrangian and Eulerian (ALE) solver in LS-DYNA is used to demonstrate the efficacy of the proposed expressions for three base rocking motions. Results from the modified analytical solutions and the finite element model are in excellent agreement.

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