An Approach to the Problem of Vibration: Structural Modification by Optimizing Density Distribution

1994 ◽  
Author(s):  
Yoshiko Kawabe ◽  
Shinobu Yoshida
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Density Distribution ◽  
Dynamic Characteristics ◽  
Material Properties ◽  
Structural Modification ◽  
Variable Density ◽  
The Finite Element Method ◽  
3 Dimensional ◽  
Mode A

Abstract This paper proposes a basic method for designing light and rigid structures that maximize the natural frequency of the structure for a designated mode. A design variable ‘density’ is introduced into the finite element method and is related to the material properties of a 3-dimensional solid element. Thus, a structure is expressed as a density distribution inside its occupiable domain, and the optimal structure is obtained by searching for the most suitable density distribution. The dynamic characteristics of the structure are improved by repeatedly modifying its density distribution.

Structural Optimization by Density Distribution for Maximization of Natural Frequency

1996 ◽  
Vol 118 (1) ◽  
pp. 157-159 ◽  
Author(s):  
Yoshiko Kawabe ◽  
Shinobu Yoshida
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Density Distribution ◽  
Natural Frequency ◽  
Material Properties ◽  
Three Dimensional ◽  
Variable Density ◽  
Design Domain ◽  
The Finite Element Method ◽  
Mode A

This paper proposes a basic method for designing light and rigid structures that have a maximum natural frequency for a designated mode. A design variable “density,” related to the material properties of a three-dimensional solid element, is introduced into the finite element method (FEM). Thus, a structure is expressed as a density distribution inside its design domain, and the optimal structure is obtained by searching for the most suitable such distribution.

The Numerical Simulation of Effective Elastic Response for WC-Co Cemented Carbide

2015 ◽  
Vol 1096 ◽  
pp. 417-421
Author(s):  
Pei Luan Li ◽  
Zi Qian Huang
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Theoretical Model ◽  
Material Properties ◽  
Cemented Carbide ◽  
Elastic Response ◽  
The Finite Element Method ◽  
Simulation Results ◽  
Element Method

By the use of finite element method, this paper predicts the effects of the shapes of reinforcements with different ductility (Co) on the effective elastic response for WC-Co cemented carbide. This paper conducts a comparative study on the material properties obtained through theoretical model, numerical simulation and experimental observations. Simulation results indicate that the finite element method is more sophisticated than the theoretical prediction.

scholarly journals Determining internal forces in modular building elements under action wind load

2018 ◽  
Vol 196 ◽  
pp. 02010
Author(s):  
Viacheslav Shirokov ◽  
Alexey Soloviev ◽  
Tatiana Gordeeva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
Dynamic Characteristics ◽  
Wind Load ◽  
Wind Loads ◽  
Bending Moments ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Internal Forces

The research paper focuses on internal forces determination in the elements of modular buildings under wind load. It provides a methodology for determining dynamic characteristics of a building and for calculating wind loads. This method is based on the following assumptions: coupling of the modules elements is rigid; coupling of block-modules with foundations is hinged-fixed; connection of blocks to each other is hinged in angular points; the floor disk in its plane is not deformed. On the basis of these assumptions the authors derived approximate and refined equations for determining forces in modules elements under static and pulsation components of wind load. The equation of bending moments determination in the pillar bearing cross-section is obtained by approximation of the graph of moments variation, calculated for the spectrum of the ratio of the pillar stiffness and the floor beam in the range from 1/64 to 64. The paper further introduces the calculation results of forces based on the proposed methodology and on the finite element method. The calculations were done while taking different values of wind load and different number of storeys in a building (from 1 to 4 floors). The obtained results are similar, the error does not exceed 5%.

Evolution of Matt Surface Topography in Aluminium Pack Rolling

2005 ◽  
Author(s):  
Hiroshi Utsunomiya ◽  
Michael P. F. Sutcliffe ◽  
Hugh R. Shercliff ◽  
Pete S. Bate ◽  
Dan B. Miller
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Surface Topography ◽  
Material Properties ◽  
Quantitative Agreement ◽  
Aluminium Foil ◽  
The Finite Element Method ◽  
Good Quantitative Agreement ◽  
Pack Rolling ◽  
Element Method

Roughening of the matt surface of pack rolled aluminium foil has been modelled. The model is based on the finite element method using isotropic plasticity. A distribution in material properties has been used to simulate the distribution of orientations through the material. The predictions of roughness show good quantitative agreement with the experiments.

scholarly journals Finite element analysis of complete model of cervical spine

2021 ◽  
Author(s):  
Muhammad Ardalani-Farsa
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Cervical Spine ◽  
Material Properties ◽  
The Finite Element Method ◽  
Complete Model ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Hard Tissues

The finite element method has been applied in the area of the cervical spine since the 1970's. In the present research work, the finite element method was employed to model, validate and analyze a complete model of the human cervical spine from C1 to T1, including interconnecting intervertebral discs, ligaments and joints. The developed model of the cervical spine was validated by the experimental results presented in the literature. As the values obtained from the finite element analysis were mainly in the range of motion observed in the experiment; it was concluded that the finite element results were consistent with the reported data in the literature. Next, the validated model of the cervical spine was examined under physiological loading modes to locate the areas bearing maximum stress in the cervical spine. Finally, to study the effect of variations in the material properties on the output of the finite element analysis, a material property sensitivity study was conducted to the C3-T1 model of cervical spine. Changes in the material properties of the soft tissues affected the external and internal responses of both the hard and soft tissue components, while changes in those of the hard tissues only affected the internal response of hard tissues.

scholarly journals Study on Vertical Dynamic Characteristics of Composite Sleeper Ballasted Track in Tunnels

2019 ◽  
Vol 275 ◽  
pp. 02015
Author(s):  
Zhenhang ZHAO ◽  
Yuting SHEN ◽  
Xue YAN ◽  
Qiankun SU
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Response ◽  
Dynamic Characteristics ◽  
Vibration Damping ◽  
The Finite Element Method ◽  
Type Iii ◽  
Damping Characteristics ◽  
Rail Systems ◽  
Ballasted Track

In order to study the vertical dynamic characteristics of the composite sleeper ballasted track in tunnels, this paper establishes a dynamic model based on the finite element method, and compares the dynamic response of vehicle, wheel and rail systems, track systems and backfill layer with the type-III concrete sleeper. The research results show that the composite sleeper ballasted tracks’ acceleration of the car body and the wheel-rail force are smaller than that of the type-III sleeper. It can meet the safety of the train and passenger comfort. Because the composite sleeper has good elasticity, The rail displacement and acceleration, the sleeper displacement and acceleration of the composite sleeper are slightly larger than the type-III sleeper ballasted track, but the effect is not great. The composite sleeper has good elasticity and large damping, so that the acceleration of the track bed and the backfill layer is less than that of the type-III sleeper ballasted track. This shows that the composite sleeper has vibration damping characteristics for the track bed and the backfill layer.

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