Modal Analysis of a Simple Supported Beam Steel Bridge Based on ANSYS

2012 ◽  
Vol 594-597 ◽  
pp. 2867-2870
Author(s):  
Dong Li Wang ◽  
Tong Li ◽  
Chun Yu Wang
Keyword(s):  
Modal Analysis ◽  
Health Monitoring ◽  
Element Model ◽  
Rate Of Change ◽  
Mode Shapes ◽  
Steel Bridge ◽  
Bridge Health Monitoring ◽  
Bridge Model ◽  
Set Up ◽  
Index Value

The purpose and significance of bridge health monitoring is described in this paper. In order to study bridge health monitoring, Firstly, a finite element model for simply supported steel beam is set up on the basis of the Infinite Element Theory and the software ANSYS in response to laboratory experient. Through adding instantaneous excitation to the mid-span, do modal analysis for different injury of steel bridge model to reveal the natural frequency and mode shapes of the different injury of steel bridges, identify the different injury by comparing the index value and the rate of change.

Harmony Response Analysis of a Simple Supported Beam Steel Bridge Based on ANSYS

2013 ◽  
Vol 303-306 ◽  
pp. 521-524
Author(s):  
Dong Li Wang ◽  
Tong Li
Keyword(s):  
Finite Element ◽  
Health Monitoring ◽  
Element Model ◽  
Rate Of Change ◽  
Response Analysis ◽  
Steel Bridge ◽  
Bridge Health Monitoring ◽  
Bridge Model ◽  
Index Value ◽  
Element Theory

The purpose and meaning of bridge health monitoring is sketched in this paper. In order to study of the structure of the bridge health monitoring problems, First of all, a finite element model for simply supported steel beam is set up on the basis of the Finite Element Theory and the software ANSYS in response to laboratory of the finite Element Theory and the software ANSYS in response to laboratory experient. Identify the different injury by comparing the index value and the rate of change. Through adding instantaneous excitation to the mid-span, do Harmony Response analysis for different injury of steel bridge model to reveal the frequency amplitude diagrams, from these diagrams can be found on the "peak" response. We can identify the different injury by comparing the index value and the rate of change.

scholarly journals Structural Health Monitoring of the Scaffolding Dismantling Process of a Long-Span Steel Box Girder Viaduct Based on BOTDA Technology

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Yong Ding ◽  
Feng Xiao ◽  
Weiwei Zhu ◽  
Tao Xia
Keyword(s):  
Health Monitoring ◽  
Strain Distribution ◽  
Time Domain Analysis ◽  
Element Model ◽  
Box Girder ◽  
Bridge Health Monitoring ◽  
Long Span ◽  
Steel Box Girder ◽  
Optical Time ◽  
Distributed Optical Fiber

In this study, a distributed optical fiber sensing technique based on Brillouin optical time-domain analysis (BOTDA) is used to construct a complete bridge health monitoring system by continuously laying distributed sensing fiber lines in a steel box girder. The bridge scaffolding dismantling process is monitored to study the variation of the strain distribution. Additionally, a bridge finite element model is built to simulate the bridge scaffolding removed condition, and the strain distribution of the long-span steel box girder viaduct after scaffolding dismantling is compared with the measured values. This study provides a reference for monitoring the scaffolding dismantling process based on BOTDA technology.

Comparing Measured Responses of an Offshore Structure with Operational Modal Analysis assisted Classical Model Approach

2020 ◽  
pp. 1-10
Author(s):  
Bruna Nabuco ◽  
Sandro D. Amador ◽  
Evangelos I. Katsanos ◽  
Ulf T. Tygesen ◽  
Erik Damgaard Christensen ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Element Model ◽  
Operating Conditions ◽  
Operational Modal Analysis ◽  
Mode Shapes ◽  
Wave Forces ◽  
Wave Load ◽  
Offshore Structure

Abstract Aiming to ensure the structural integrity of an offshore structure, wave-induced responses have been measured during normal operating conditions. Operational Modal Analysis is applied to the data obtained from continuously monitoring the structure. Sensors placed only on the topside of an offshore platform are sufficient to provide information to identify the modal properties of the structure, such as natural frequencies, damping ratios, and mode shapes. A finite element model is created and updated in line with the identified dynamic properties for applying a modal expansion technique in the interest of accessing information at any point of the structure. Wave radars are also placed at the platform from which the wave forces are calculated based on basic industrial standard models. In this way, the wave kinematics are estimated according to the linear wave theory associated with Wheeler stretching. Since this study is related to offshore structures composed by slender elements, the wave forces are estimated using Morison formulation. By assigning typical values to the drag and inertia coefficients, wave loads are estimated and applied to the updated finite element model. For the diffraction effect, the wave load has also been evaluated according to MacCamy and Fuchs theory. The responses obtained from this procedure are compared with measured responses. In addition to describing the process, this paper presents a case study to verify the theory using monitoring data from a tripod jacket. Results indicate realistic response estimation that contributes to the knowledge about the state of the structure.

scholarly journals Parameter identification for a point-supported cross laminated timber slab based on experimental and numerical modal analysis

2020 ◽  
Author(s):  
Michael Kawrza ◽  
Thomas Furtmüller ◽  
Christoph Adam ◽  
Roland Maderebner
Keyword(s):  
Modal Analysis ◽  
Model Updating ◽  
Dynamic Properties ◽  
Element Model ◽  
Mode Shapes ◽  
Cross Laminated Timber ◽  
Numerical Studies ◽  
Robust Parameter ◽  
Updating Procedure ◽  
Sensor Positions

AbstractIn this paper, the dynamic properties of a point-supported cross-laminated timber slab are studied in order to determine the elastic material parameters on this basis. A detailed experimental modal analysis of the slab with dimensions 16.0 m x 11.0 m is performed, and seven modes including the natural frequencies, damping ratios and mode shape components at 651 sensor positions are identified. The found mode shapes are complex due to environmental influences that occurred during the two-day measurement campaign. This error is corrected by eliminating these influences. A finite element model of the slab is presented, whose parameters in terms of material properties and boundary conditions are determined by a model updating procedure. Based on the modal properties of the seven experimentally identified modes, an accurate and robust parameter set is obtained, which can be used in further numerical studies of the considered CLT to check serviceability limit criteria.

Modal Analysis for Swing-Arm of LED Die Bonder

2011 ◽  
Vol 422 ◽  
pp. 379-382
Author(s):  
Wei Chuang Quan ◽  
Mei Fa Huang ◽  
Zhi Yue Wang ◽  
Da Wei Zhang
Keyword(s):  
Modal Analysis ◽  
Vibration Mode ◽  
Three Dimensional ◽  
Element Model ◽  
Mode Shapes ◽  
Vibration Modes ◽  
Lead Frame ◽  
Swing Arm ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Led die bonder used for bond lead frame and chip is one of the key equipment of led production line. The swing-arm is an important component of led die bonder and its dynamic characteristics will directly affect the piece accuracy. At present, the accuracy and efficiency of led die bonder are limited because of the vibration of the swing-arm. In solving this problem, a three-dimensional finite-element model for swing-arm is built to provide analytical frequencies and vibration modes. Then the modal distribution and vibration mode shapes for swing-arm are obtained after analyzing the modal by ansys10.0. Finally the dynamics effects of this structure by modal frequency and vibration mode are analyzed. The modal analysis of structural would provide the reference to dynamics analysis and structural optimization for swing-arm in practical use.

Modal Analysis of Two Wheels Scooter Based on Solidworks

2014 ◽  
Vol 960-961 ◽  
pp. 1420-1423
Author(s):  
Zhi Dong Huang ◽  
Guo Fei Li ◽  
Juan Cong ◽  
Yun Wang ◽  
Wei Na Yu ◽  
...  
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Dynamic Design ◽  
Driving System ◽  
Set Up ◽  
The Finite Element Model

Based on Solidworks software, the three-dimensional model of two wheels scooter is set up. The finite element model of two wheels scooter is generated. Modal analysis of driving system and telescopic mechanism of bar on two wheels scooter is investigated. The first five orders natural frequency and major modes of driving system and telescopic mechanism of bar are clarified. The method and the result can be used as a reference of dynamic design and lay foundation for calculation and analysis of dynamic response for the two wheels scooter.

Experimental Modal Analysis of a Half-Scale Model Twin-Engine Aircraft Rear Fuselage Engine Mount Support Frame

2017 ◽  
Author(s):  
Diego A. Chamberlain ◽  
Chris K. Mechefske
Keyword(s):  
Modal Analysis ◽  
Natural Frequencies ◽  
Testing Procedure ◽  
Modal Testing ◽  
Scale Model ◽  
Mode Shapes ◽  
Component Testing ◽  
Fitting Procedures ◽  
Engine Mount ◽  
Set Up

Experimental modal testing using an impact hammer is a commonly used method for obtaining the modal parameters of any structure for which the vibrational behavior is of interest. Natural frequencies and associated mode shapes of the structure can be extracted directly from measured FRFs (Frequency Response Functions) through various curve fitting procedures. This paper provides an overview of the modal testing conducted on an aerospace component. Testing set-up, experimental equipment and the methodology employed are all described in detail. Further validation of the testing procedure was done by ensuring that the experimental results satisfy the requirements of repeatability, reciprocity and linearity. The relevant ISO standard has been referenced and important concepts to modal analysis are expanded upon. Recorded natural frequencies, coherence and a description of the observed mode shapes are presented along with notable trends.

Free Modal Analysis for the Pinion of Logarithmic Spiral Bevel Gear with 20CrMnTi

2015 ◽  
Vol 667 ◽  
pp. 512-517
Author(s):  
Li Zhi Gu ◽  
Tie Ming Xiang ◽  
Peng Li ◽  
Jian Min Xu
Keyword(s):  
Modal Analysis ◽  
Natural Frequencies ◽  
Logarithmic Spiral ◽  
Element Model ◽  
Structure Design ◽  
Bevel Gear ◽  
Mode Shapes ◽  
Spiral Bevel Gear ◽  
Low Carbon ◽  
Spiral Bevel

In order to obtain the pinion's natural frequencies and mode shapes of a new kind of spiral bevel gear (SBG) which is logarithmic spiral bevel gear (LSBG) in the unconstrained state for the purpose of dynamic characteristics study, select the low carbon alloy steel 20CrMnTi (China specification) with good mechanical properties, which the carbon content is 0.17%-0.23%, the elastic modulus E=2.06675×1011Pa, the Poisson's ratio is 0.25, and the density is 7.85×103kg/m3, the finite element model of LSBG pinion which consist of 35100 nodes, 19889 Solid187 tetrahedron FEM elements is established by using free meshing method based on LSBG pinion's physical model in this paper. Solve the modal parameters of the first 6 orders, draw the main vibration mode shape according to the first 6 orders natural frequencies respectively. The first 6 orders critical revolution speeds are calculated by the first 6 orders corresponding natural frequencies, and the LSBG pinion allowable work revolution speeds are 117074.16 revolutions per minute. The free modal analysis of the conventional SBG pinion with the same parameters is done for comparison with LSBG pinion. The results show the LSBG pinion's nature frequency and the critical revolution speed are both lower than that of conventional SBG. The conclusions reflect the vibration response characteristics of LSBG pinion, and provide theoretical basis for dynamic response, structure design and optimization of LSBG pinion.

scholarly journals Bridge Health Monitoring via Displacement Reconstruction-Based NB-IoT Technology

2020 ◽  
Vol 10 (24) ◽  
pp. 8878
Author(s):  
John Thedy ◽  
Kuo-Wei Liao ◽  
Chun-Chieh Tseng ◽  
Chia-Ming Liu
Keyword(s):  
Health Monitoring ◽  
Micro Electro Mechanical System ◽  
Small Scale ◽  
Bridge Health Monitoring ◽  
Bridge Model ◽  
Narrow Bandwidth ◽  
Acceleration Sensors ◽  
Bridge Damage ◽  
The Difference ◽  
Displacement Reconstruction

An aged bridge’s performance is affected by degradation and becomes one of the major concerns in maintenance. A preliminary, simple and workable procedure of bridge damage detection is required to minimize maintenance costs. In the past, frequency is one of the most common indicators to detect damage occurrence. Recent research found that using frequency as a health indicator still has room to improve. Alternatively, dynamic displacement is used as an indicator in the current study. These dynamic displacements are reconstructed based on measured acceleration records from micro electro mechanical system (MEMS) sensors. The Newmark-beta method with Windows is proposed to acquire the reconstructed displacements of considered bridges. To demonstrate the accuracy and applicability of the proposed approach, three different experiments are carried out; (i) A small scale bridge with the implementation of MEMS acceleration sensors; (ii) a numerical complex finite element method (FEM) bridge model; (iii) an actual bridge with the implementation of MEMS acceleration sensors and narrow bandwidth Internet of things (NB-IoT) technology. The first experiment shows that the proposed method can successfully identify the difference between damaged/undamaged bridges and determine damage location. The second experiment indicates that the proposed method is able to identify the difference between stiffened/unstiffened bridges. The last experiment shows the applicability of the proposed method on an actual bridge health monitoring project.

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