Predicting the Natural Frequency of Train Structures Using Detailed Finite Element Models

2016 ◽  
Author(s):  
Robert A. MacNeill ◽  
Glenn Gough
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Holistic Approach ◽  
Light Rail ◽  
Element Analysis ◽  
Fea Model ◽  
High Level ◽  
Structural Mass

Train carbody and truck structures are designed to exhibit primary natural frequency modes great enough to avoid unwanted resonant oscillations with normal track interactions. Critical bounce modes can be excited by typical track in the 2–4 Hz range. Trains are designed with first modes above this threshold. Historically, simplified approaches are employed to predict natural frequencies of the main truck and carbody train structures independently. Since the advent of high powered computing, more detailed finite element analysis (FEA) eigenvalue approaches have been used to more accurately predict natural frequency of structures. Still, the typical FEA approach uses simplified boundary conditions and partial models to determine natural frequencies of individual components, neglecting the interaction with other connected structures. In this paper, a detailed, holistic approach is presented for an entire Light Rail Vehicle (LRV). The analysis is performed on a fully detailed FEA model of the LRV, including trucks and suspension, carbody structures, non-structural mass, articulation, as well as intercar and truck-carbody connections. The model was developed for detailed crashworthiness investigations, which requires a high level of fidelity compared to what is typically required for static and modal analysis. Using the same model for multiple purposes speeds up development while also improving the accuracy of the analyses. In this paper, the modal analysis methodology developed is described. A case study is presented investigating the often neglected contribution of windows, cladding, and flooring on the overall carbody natural frequency.

Strength Design for Star Sprocket Based on ANSYS

2014 ◽  
Vol 635-637 ◽  
pp. 312-315
Author(s):  
Lin Hong ◽  
Ying Jie Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Dynamic Optimization ◽  
Natural Frequencies ◽  
Analysis Software ◽  
Optimization Analysis ◽  
Element Analysis ◽  
Chain Conveyor

A star sprocket is an important component of U-shaped slide chain conveyor, so it is particularly important to be analyzed. It conducts modal analysis of star sprocket by using large finite element analysis software, ANSYS, calculates natural frequencies of the first five and the corresponding modes and analyzes natural frequency affected by sprocket tooth thickness. The result provides basic theory for dynamic optimization analysis of U-shaped slide chain conveyor.

Investigation of stiffness of small wind turbine blade based on vibration analysis technique

2019 ◽  
Vol 44 (1) ◽  
pp. 49-59
Author(s):  
Nilesh Chandgude ◽  
Nitin Gadhave ◽  
Ganesh Taware ◽  
Nitin Patil
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Wind Turbine ◽  
Natural Frequency ◽  
Vibration Analysis ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Element Analysis ◽  
Finite Element Software ◽  
Small Wind Turbine

In this article, three small wind turbine blades of different materials were manufactured. Finite element analysis was carried out using finite element software ANSYS 14.5 on modeled blades of National Advisory Committee for Aeronautics 4412 airfoil profile. From finite element analysis, first, two flap-wise natural frequencies and mode shapes of three different blades are obtained. Experimental vibration analysis of manufactured blades was carried out using fast Fourier transform analyzer to find the first two flap-wise natural frequencies. Finally, the results obtained from the finite element analysis and experimental test of three blades are compared. Based on vibration analysis, we found that the natural frequency of glass fiber reinforced plastic blade reinforced with aluminum sheet metal (small) strips increases compared with the remaining blades. An increase in the natural frequency indicates an increase in the stiffness of blade.

Modal Analysis of Marine Propeller Submerged in Fluid

2014 ◽  
Vol 1030-1032 ◽  
pp. 1201-1205
Author(s):  
Hong Ren ◽  
Fan Chun Li ◽  
Tian Yu Zhao
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Three Dimensional ◽  
Secondary Development ◽  
Marine Propeller ◽  
Fluid Inertia ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The present work is aimed to free vibration characteristics of marine propeller in fluid, and analyze the influence of fluid inertial effect on propeller. The fully coupled three dimensional finite element method is applied, and the commercial finite element code, ANSYS WORKBENCH, has been used to perform modal analysis for both wet and dry configurations via fluid-structure interaction APDL commands for secondary development. On this basis, analyze a marine propeller in air and in fluid with finite element analysis, then the differences of natural vibration frequencies and vibration modes of the propeller for different boundary conditions are discussed. In addition, the natural frequencies curves are presented. Results show that the natural frequencies of propeller in fluid are significantly lower than those in air, the fluid inertia effect also has some influences on vibration mode.

The Finite Element Analysis of the Wind Turbines's Rotary Support

2011 ◽  
Vol 347-353 ◽  
pp. 1276-1280
Author(s):  
Hong Liang Hu ◽  
Rui Jie Wang ◽  
Chun Ling Meng ◽  
Guo Feng Li
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Static Analysis ◽  
Theoretical Basis ◽  
Dynamic Performance ◽  
Element Analysis ◽  
The Finite Element Analysis

Abstract. Combining characteristic of the Wind Tturbines's rotary support, using finite element method, the paper probe the rotary support finite element analysis of static and modal analysis. Through the static analysis of the rotary support, receiving the deformation and stress-strain results; through modal analysis,receiving the 6-order natural frequency and vibration shape.Analyzing of the main failure forms and Dynamic performance ,the results provide a theoretical basis of improvement of the design and to finalize the program.

Modal Analysis of 160KVA Dry-Type Transformer Based on ANSYS

2012 ◽  
Vol 229-231 ◽  
pp. 919-922
Author(s):  
Bao Dong Bai ◽  
Guo Hui Yang ◽  
Bing Yin Qu ◽  
Jian Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Modal Analysis ◽  
Noise Level ◽  
Natural Frequencies ◽  
Analysis Software ◽  
Element Analysis ◽  
The Core ◽  
The Finite Element Analysis ◽  
Simulation Results

In this paper, the modal analysis was carried out on the core and cavity of a 160KVA dry-type transformer based on the finite element analysis software of ANSYS. And the simulation results of the natural frequencies and modal shapes were obtained, which provided a theoretical guidance to the design of the transformer structure, and were meaningful to reduce the vibration and noise level of the transformer.

scholarly journals Modal Analysis of Optimized Trapezoidal Stiffened Plates under Lateral Pressure and Uniaxial Compression

2021 ◽  
Vol 2 (4) ◽  
pp. 681-693
Author(s):  
Zoltán Virág ◽  
Sándor Szirbik
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Modal Analysis ◽  
Uniaxial Compression ◽  
Natural Frequencies ◽  
Lateral Pressure ◽  
Mode Shapes ◽  
Stiffened Plates ◽  
Elastic Model ◽  
Element Analysis

This paper deals with the modal analysis of optimized trapezoidal stiffened plates with simple supported conditions on the four edges of the base plate. The main objective of the finite element analysis is to investigate the natural frequencies and mode shapes of some stiffened structures subjected to lateral pressure and uniaxial compression in order to identify any potentially dangerous frequencies and eliminate the failure possibilities. The natural frequencies and mode shapes are important parameters in the design of stiffened plates for dynamic loading conditions. In this study, the numerical analysis is performed for such a design of this kind of welded plates which have already been optimized for lateral pressure and uniaxial compression. The objective function of the optimization to be minimized performed with the Excel Solver program is the cost function which contains material and fabrication costs for Gas Metal Arc Welding (GMAW) welding technology. In this study, the eigenvalue extraction used to calculate the natural frequencies and mode shapes is based on the Lanczos iteration methods using the Abaqus software. The structure is made of two grades of steel, which are described with different yield stress while all other material properties of the steels in the isotropic elastic model remain the same. Drawing the conclusion from finite element analysis, this circumstance greatly affects the result.

A Comparative Study of Valve Natural Frequency Estimation Using Finite Element Analysis (FEA), Raleigh’s Principles and Laboratory Tests

2014 ◽  
Author(s):  
L. Ike Ezekoye ◽  
Preston A. Vock ◽  
Ronald S. Farrell ◽  
Richard J. Gradle
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
The Other ◽  
Test Results ◽  
Lumped Mass ◽  
Element Analysis ◽  
Valve Body ◽  
Other Hand

The natural frequency of valves is an important design requirement to ensure that valves do not go into resonance during operation and consequently fail structurally or fail to perform their design and safety related functions. Besides its impact on operability, valve resonance can initiate piping vibration that could damage pipes and their supports; which is undesirable. As important as equipment natural frequency is to valve operability, one would expect that testing should be the de facto method for confirming its value. Ideally, this should be the case, however, cost considerations limit the extent to which testing is used. On the other hand, testing does have some issues with respect to accuracy such as the effect of supporting structure flexibility resulting in a conservatively lower natural frequency measurement. In addition, the multiplicity of valves in nuclear power plants with different designs, sizes and safety classes limit the use of testing to establish valve natural frequencies except when required in the equipment specifications. Frequently, valve natural frequencies are determined by analysis either using finite element techniques (FEA) or by first principles of beam and mass models; the latter being more frequently used. This paper presents the studies performed to correlate valve natural frequency test results to the results derived from analytical techniques using Raleigh’s energy principle and from finite element analysis (FEA) methods. In a previous paper on valve natural frequency [1], Ezekoye et al. presented a model for estimating valve natural frequency by incorporating mass inertia of the valve structures with the more traditional methods that are based on a lumped mass model to determine displacements. In the process, the flexibility of the extended structure (otherwise referred to as the superstructure) and the valve body itself are considered. Using limited test data, Ezekoye et al. showed that there is merit in using their enhanced analysis model. Their correlation was promising. The finite element analysis, on the other hand, is a well-established technique for solving complex structural mechanics problems and should be expected to provide reasonable results comparable to actual valve tests provided the boundary conditions provide a reasonable representation of the actual valves tested. In this paper, ANSYS Version 12.1 was used to model valve natural frequencies. Additionally, a more extensive testing of valves for natural frequency was performed in this paper than was reported in Reference 1. The results of both the FEA and the Raleigh’s principle model as presented in Ezekoye et al. are compared against the test results. By comparing the three results, strengths and weaknesses of each method become apparent. The choice of whether or not one chooses to test or perform analysis depends on the valve specification requirement and the preference of the designer.

Modal Analysis of Special High-Pressure Seamless Cylinders Based on ANSYS 12.0

2013 ◽  
Vol 546 ◽  
pp. 122-126
Author(s):  
Xiao Long Hu ◽  
Zhong Bao Qin ◽  
Jian Feng Guo ◽  
Ying Juan Yue
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Pressure ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Vibration Frequencies ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
The Impact

This paper discussed the impact of the quantity and position of constraint on the natural frequency of special high-pressure seamless cylinders. The Finite Element modal of the special high-pressure seamless cylinders was constructed based on ANSYS12.0. The vibration frequencies and modal shapes under different conditions were obtained by the Finite Element analysis. The result will be used for improving the safe capability of the Special High-pressure Seamless Cylinders.

scholarly journals Modal Analysis of a Thick-Disk Rotor with Interference Fit Using Finite Element Method

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Yuhua Fan ◽  
Hongchang Ding ◽  
Maoyuan Li ◽  
Jiacheng Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Bending Stiffness ◽  
Thick Disk ◽  
Interference Fit ◽  
Motion Equations ◽  
Ansys Workbench

This paper is concerned with the modal analysis of a thick-disk rotor, which consists of an elastic shaft with a rigid thick disk assembled by interference fit, and the width of the thick disk is not negligible. Firstly, the friction moment on the contact surface of disk and shaft is deduced in terms of elastic theory, and a new enhanced coefficient of bending stiffness of assembly body is proposed and calculated for the first time. Secondly, the effect of the width of thick disk on diametrical moment of inertia, as well as the enhanced coefficient of bending stiffness of interference-fit part between disk and shaft, is included in the motion equations of thick-disk rotor, which are established based on finite element method, and the natural frequencies of rotor are obtained by solving the motion equations. Then the modal analysis is performed to get the natural frequencies in ANSYS Workbench, in which the friction coefficient and interference fit are set to be the same as those of the finite element calculation method. At last the modal experiment is done to verify the accuracy of calculation and simulation. The results show that the calculation values using enhanced stiffness of assembly part are in good agreement with those of ANSYS Workbench and experiment, and the percent errors of the first natural frequency and the second natural frequency are down to about 0.32% and 0.83%, respectively.

Modal Analysis of Concrete Pump Truck Boom

2014 ◽  
Vol 889-890 ◽  
pp. 148-151 ◽  
Author(s):  
Kun Li Mao
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Hydraulic Cylinder ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Concrete Pumping ◽  
Pumping Mode ◽  
Concrete Pump Truck ◽  
Concrete Pump

Boom is one of key components of concrete pump trucks which can be looked as a projecting beam when unfolded at pumping mode. Under different concrete pumping modes, vibration of boom is serious for the hydraulic cylinder switching over shock, which can lead to the early damage of boom structure. In the finite element analysis software, boom of 37 meters concrete pump truck is simulated for its modal. Natural frequencies and corresponding modes are got and analyzed. To reduce vibration of concrete pump trucks, advices are presented by finite element modal analysis.

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