The Simplified Model and the Critical Angle of the Curved Bridges with Multi-Dimensional Earthquake Excitation

2014 ◽  
Vol 1065-1069 ◽  
pp. 1518-1524
Author(s):  
Xi Mei Li ◽  
Yong Feng Du
Keyword(s):  
Finite Element ◽  
Critical Angle ◽  
Degrees Of Freedom ◽  
Design Method ◽  
Curve Beam ◽  
Analysis Model ◽  
Curved Bridges ◽  
Mass Model ◽  
Double Mass ◽  
Matlab Programming

The existing methods of curve beam bridge is the finite element method, the modeling and analysis of complex, heavy workload, not suitable for the proposed design method of regularity. According to the character of curved bridge, the bridge superstructure and piers is simplified as packing quality model that have two levels of degrees of freedom and a surrounding mass center shaft torsion degree of freedom, then the analysis model of double mass simplified 6 degrees of freedom is established, studying the dynamic characteristics and the structure vibration behavior through the dynamics equation of curved bridges. Example show that,the results of double mass model with the traditional of finite element model is consistent, double mass model has simple calculation method and can consider the influence of sensitive factors, with the help of programming is more suitable for the proposed design method of regularity. At last, Application MATLAB programming discussed the critical angle of the curved bridges under multi-dimensional earthquake based on double mass model, after change the curve bridge related parameters only one operation can achieve the most disadvantaged angle.

The Design Method of V-Tooth Coupling

2013 ◽  
Vol 871 ◽  
pp. 347-351
Author(s):  
Dun Cai Lei ◽  
Jin Yuan Tang
Keyword(s):  
Finite Element ◽  
Design Method ◽  
Operating Conditions ◽  
Bending Stress ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Precision Design ◽  
The Finite Element Analysis ◽  
Paper Work

A lecture on the method to compute the the stress of V-tooth coupling under the actual operating conditions. the finite element analysis model of V-tooth coupling under the preload, axial load and torsion was established by used of the software ABAQUS,and the distribution of the bending stress at the root was obtained. The analytical method to compute the bending stress of V-tooth disk is deduced based on the basic principle of material mechanics, and the relative error within 10% compared with the results of finite element analysis.The paper work provide the reference for the precision design of V-tooth coupling.

scholarly journals Analysis of dynamic characteristics of climbing formwork under wind loads

2019 ◽  
Vol 79 ◽  
pp. 01016
Author(s):  
Shicheng Hu ◽  
Jun Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Characteristics ◽  
Calculation Method ◽  
Design Method ◽  
Element Model ◽  
Wind Load ◽  
Bending Effect ◽  
Matlab Programming ◽  
The Finite Element Model

This article took the climbing formwork which constructed on the bridge at a height of 100 meters as the prototype, then established the finite element model and conducted modal analysis. The APDL language is used to load the wind load which is simulated by the Matlab programming then calculated the displacement and acceleration responses of the climbing formwork and further. The results show that the bending effect of the climbing formwork is more obvious. This calculation method of calculating the wind load, improve the anti-wind design method of the climbing formwork.

Finite element analysis of ballastless track slabs reinforced with fiber-reinforced polymer bars

2021 ◽  
pp. 136943322110273
Author(s):  
Yang Yang ◽  
Guan-Jun Zhang ◽  
Gang Wu ◽  
Da-fu Cao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Method ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Analysis Model ◽  
Element Analysis ◽  
Ballastless Track ◽  
Reinforced Polymer ◽  
Prestressed Materials

Fiber-reinforced polymer–reinforced ballastless track slabs not only improve the insulation performance but also have advantages in their mechanical properties. The objective of the article is to propose a corresponding design method of the ballastless track slabs considering different parameters by a finite element analysis model. The deformation performance of the ballastless track slabs, as well as the prediction results of several models, was studied considering the different prestress levels, reinforcement ratios, and prestressed materials. The results show that ACI 440.4R-04 and Bischoff models are suggested for predicting the deflection of a ballastless track slab when the prestress level is between 30% and 60% and the Brown and Bartholomew model is suitable for those with a prestress level below 30%.

scholarly journals Measured Impact

2018 ◽  
Vol 140 (01) ◽  
pp. 42-45
Author(s):  
James G. Skakoon
Keyword(s):  
Finite Element ◽  
Corpus Callosum ◽  
Degrees Of Freedom ◽  
Head Injuries ◽  
Analysis Model ◽  
Element Analysis ◽  
Falx Cerebri ◽  
Institute Of Technology ◽  
The Impact ◽  
The Brain

This article focuses on an innovative methodology developed by researchers at Stanford University. The new way of measuring the forces that cause head injuries aim to change how engineers protect professional and weekend athletes. By embedding both accelerometers and gyroscopes within the mouth guards, the laboratory tracked all six degrees of freedom and slashed data errors to 10 percent or less. According to one of the developer, since the upper teeth are firmly coupled to the bones of the cranium, the mouthguards can provide data accurate enough for the lab to use in finite element models to describe what is happening inside the brain. The team input the incident’s kinematics data into a finite element analysis model of the brain developed by the KTH Royal Institute of Technology in Sweden. This enabled them to simulate how different structures within the brain responded to the impact. The computer simulation showed that the falx cerebri appears to be the culprit. It is a rigid vertical sheet that separates the brain’s two lobes. It lies right above the corpus callosum and extends upward, attaching to the skull at the very top. It conducts impact energy from the skull deep into the brain, where it oscillates and induces strain in the corpus callosum.

Finite Element Analysis of Engine Fixed Parts Assembling Process

2014 ◽  
Vol 651-653 ◽  
pp. 738-741
Author(s):  
You Lin Ling ◽  
Yan Liu ◽  
Jian Zhang ◽  
Wen Xian Tang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Diesel Engine ◽  
Mechanical Performance ◽  
Design Method ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
The Finite Element Analysis ◽  
Marine Diesel

In order to select the best design method for stay bolts in the diesel engine assembling process, main fixed parts of some MAN low-speed marine diesel engine were analyzed based on finite element analysis software Hyperworks. The mechanical performance of bottom, frame and cylinder under the effect of the four kinds of assembling methods was investigated. Ultimately, the best assembling process was confirmed. Results indicated that the finite element analysis model was reliable and exactly. The middle to both sides assembly was the best among the four methods.

The Influence of Loading Position in A Priori High Stress Detection using Mode Superposition

2020 ◽  
Vol 1 (1) ◽  
pp. 93-102
Author(s):  
Carsten Strzalka ◽  
◽  
Manfred Zehn ◽  
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
A Priori ◽  
High Stress ◽  
Von Mises Stress ◽  
Detailed Knowledge ◽  
Variable Loading ◽  
Numerical Effort ◽  
Von Mises

For the analysis of structural components, the finite element method (FEM) has become the most widely applied tool for numerical stress- and subsequent durability analyses. In industrial application advanced FE-models result in high numbers of degrees of freedom, making dynamic analyses time-consuming and expensive. As detailed finite element models are necessary for accurate stress results, the resulting data and connected numerical effort from dynamic stress analysis can be high. For the reduction of that effort, sophisticated methods have been developed to limit numerical calculations and processing of data to only small fractions of the global model. Therefore, detailed knowledge of the position of a component’s highly stressed areas is of great advantage for any present or subsequent analysis steps. In this paper an efficient method for the a priori detection of highly stressed areas of force-excited components is presented, based on modal stress superposition. As the component’s dynamic response and corresponding stress is always a function of its excitation, special attention is paid to the influence of the loading position. Based on the frequency domain solution of the modally decoupled equations of motion, a coefficient for a priori weighted superposition of modal von Mises stress fields is developed and validated on a simply supported cantilever beam structure with variable loading positions. The proposed approach is then applied to a simplified industrial model of a twist beam rear axle.

Design and Research of Double-Drum Winch with Anti-Pressure Wheel

2012 ◽  
Vol 479-481 ◽  
pp. 1709-1713
Author(s):  
Kai An Yu ◽  
Tao Yang ◽  
Chang Zhi Gong
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Finite Element Methods ◽  
Design Method ◽  
New Method

In view of the problems of large stress and severe bearing heating in double-drum winch at present, this paper adopted a new method to enhance bearing capacity for double-drum winch by adding anti-pressure wheels between two drums. Finite element methods were used to analyze the strength of 4000kN-traction double-drum winches with anti-pressure wheels and without anti-pressure wheels respectively. The results of the analysis revealed that the stress of the cylinder bearing decreased from 264MPa to 167MPa. The new method by adding anti-pressure wheels had remarkably improved the endurance of the bearing. Therefore, the design method can be widely used in large-traction double-drum winch.

scholarly journals A Finite Element Approach to the Analysis of Rotating Bladed-Disk Assemblies Coupled With Flexible Shaft

1994 ◽  
Author(s):  
Wen Zhang ◽  
Wenliang Wang ◽  
Hao Wang ◽  
Jiong Tang
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Coupled System ◽  
Equation Of Motion ◽  
Coupled Systems ◽  
The Finite Element Method ◽  
Bladed Disk ◽  
Modal Synthesis ◽  
Element Approach ◽  
Final Equation

A method for dynamic analysis of flexible bladed-disk/shaft coupled systems is presented in this paper. Being independant substructures first, the rigid-disk/shaft and each of the bladed-disk assemblies are analyzed separately in a centrifugal force field by means of the finite element method. Then through a modal synthesis approach the equation of motion for the integral system is derived. In the vibration analysis of the rotating bladed-disk substructure, the geometrically nonlinear deformation is taken into account and the rotationally periodic symmetry is utilized to condense the degrees of freedom into one sector. The final equation of motion for the coupled system involves the degrees of freedom of the shaft and those of only one sector of each of the bladed-disks, thereby reducing the computer storage. Some computational and experimental results are given.

Modeling and experimental verification on directivity of an electret cell array loudspeaker

2012 ◽  
Vol 24 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Yu-Chi Chen ◽  
Wen-Ching Ko ◽  
Han-Lung Chen ◽  
Hsu-Ching Liao ◽  
Wen-Jong Wu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Digital Control System ◽  
Analysis Model ◽  
Cell Array ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
The Finite Element Analysis ◽  
Directivity Characteristics

We propose a model to give us a method to investigate the characteristic three-dimensional directivity in an arbitrarily configured flexible electret-based loudspeaker. In recent years, novel electret loudspeakers have attracted much interest due to their being lightweight, paper thin, and possessing excellent mid- to high-frequency responses. Increasing or decreasing the directivity of an electret loudspeaker makes it excellent for adoption to many applications, especially for directing sound to a particular area or specific audio location. Herein, we detail a novel electret loudspeaker that possesses various directivities and is based on various structures of spacers instead of having to use multichannel amplifiers and a complicated digital control system. In order to study the directivity of an electret loudspeaker based on an array structure which can be adopted for various applications, the horizontal and vertical polar directivity characteristics as a function of frequency were simulated by a finite-element analysis model. To validate the finite-element analysis model, the beam pattern of the electret loudspeaker was measured in an anechoic room. Both the simulated and experimental results are detailed in this article to validate the various assertions related to the directivity of electret cell-based smart speakers.

scholarly journals Higher Order Multiscale Finite Element Method for Heat Transfer Modeling

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3827
Author(s):  
Marek Klimczak ◽  
Witold Cecot
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Degrees Of Freedom ◽  
Higher Order ◽  
Shape Functions ◽  
Multiscale Finite Element Method ◽  
Multiscale Finite Element ◽  
Steady State Heat ◽  
Steady State Heat Transfer

In this paper, we present a new approach to model the steady-state heat transfer in heterogeneous materials. The multiscale finite element method (MsFEM) is improved and used to solve this problem. MsFEM is a fast and flexible method for upscaling. Its numerical efficiency is based on the natural parallelization of the main computations and their further simplifications due to the numerical nature of the problem. The approach does not require the distinct separation of scales, which makes its applicability to the numerical modeling of the composites very broad. Our novelty relies on modifications to the standard higher-order shape functions, which are then applied to the steady-state heat transfer problem. To the best of our knowledge, MsFEM (based on the special shape function assessment) has not been previously used for an approximation order higher than p = 2, with the hierarchical shape functions applied and non-periodic domains, in this problem. Some numerical results are presented and compared with the standard direct finite-element solutions. The first test shows the performance of higher-order MsFEM for the asphalt concrete sample which is subject to heating. The second test is the challenging problem of metal foam analysis. The thermal conductivity of air and aluminum differ by several orders of magnitude, which is typically very difficult for the upscaling methods. A very good agreement between our upscaled and reference results was observed, together with a significant reduction in the number of degrees of freedom. The error analysis and the p-convergence of the method are also presented. The latter is studied in terms of both the number of degrees of freedom and the computational time.

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