scholarly journals Study on the Applicability of Dynamic Factor Standards by Comparison of Spring Constant Based Dynamic Factor of Ballasted and Concrete Track Structures

2020 ◽  
Vol 10 (23) ◽  
pp. 8361
Author(s):  
Jaeik Lee ◽  
Kyuhwan Oh ◽  
Yonggul Park ◽  
Junhyeok Choi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Field Measurement ◽  
Function Analysis ◽  
Measurement Data ◽  
Spring Constant ◽  
Dynamic Factor ◽  
Calculation Methods ◽  
Element Analysis ◽  
Standard Design

Dynamic factor evaluation method calculation methods outlined by Eisenmann (DAFEisenmann) and the American Railway Engineering Association (DAFArea) are used to calculate the dynamic factor during design and for trackside measurement, respectively, in nations where the construction of concrete track structures is relatively new. In this situation, dynamic factor calculation methods may be incorrect, and this is demonstrated by comparison of the respective track types’ total spring constant. A finite element analysis of a standard design railway track is conducted, and the design total spring constant (TSC, or K) obtained from the time history function analysis is compared to the TSC of existing tracks through trackside measurement results. The comparison result shows that TSC obtained by finite element analysis result is 22% higher than that of the trackside measurement value, indicating that the TSC is conservative in the current track design. Considering the proportional relationship between TSC and dynamic factor, it is estimated that the dynamic factor currently being applied in track design is also conservative. Based on these findings, an assessment of the applicability of different dynamic factors (DAFEisenmann and DAFArea), theoretical calculation and field measurement (DAFField) using the probabilistic analysis of wheel loads from the field measurement data is conducted. A correlative analysis between DAFEisenmann and DAFArea shows that DAFEisenmann and DAFArea were estimated to be higher by 33% and 27% in ballasted track and by 39% and 30% in concrete track than the dynamic factor derived from field measurement, respectively, which indicates that the dynamic factor currently in use can potentially lead to over-estimation in track design and maintenance.

scholarly journals A Simulation Study to Calculate a Structure Conceived by Eugène Viollet-le-Duc in 1850 with Finite Element Analysis

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2576 ◽  
Author(s):  
Adela Rueda Márquez de la Plata ◽  
Pablo Alejandro Cruz Franco
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Simulation Study ◽  
Complex Materials ◽  
Calculation Methods ◽  
Element Analysis ◽  
Finite Element Calculations ◽  
Single Structure ◽  
Working Together ◽  
Subsequent Calculation

This study aims to investigate the application of finite element calculations to mixed structures of complex materials. As an example, we chose a vault designed by Eugène Viollet-le-Duc in 1850, at which time it was not possible to verify the complexities of the different materials working together in a single structure using these calculation methods. To carry out the simulation, the internal qualities of each material and its current equivalent are taken into account. Thus, the composition of each element is crucial for its integration into the whole structure and its modeling and subsequent calculation. With this research, we show that a finite element analysis can also be applied to structures that are yet to be built. Furthermore, we verify the technological, construction and materials knowledge that has led us here and demonstrate that what was once a utopian vision can now be realized using the structures and materials we have access to today.

scholarly journals Long-Term Performance of Trestle Bridges: Case Study of an Indonesian Marine Port Structure

2020 ◽  
Vol 8 (5) ◽  
pp. 358 ◽  
Author(s):  
Yusak Oktavianus ◽  
Massoud Sofi ◽  
Elisa Lumantarna ◽  
Gideon Kusuma ◽  
Colin Duffield
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Service Life ◽  
Field Measurement ◽  
Field Measurements ◽  
Element Analysis ◽  
Moment Capacity ◽  
Non Destructive

A precast reinforced concrete (RC) T-beam located in seaport Terminal Peti Kemas (TPS) Surabaya built in 1984 is used as a case study to test the accuracy of non-destructive test techniques against more traditional bridge evaluation tools. This bridge is mainly used to connect the berth in Lamong gulf and the port in Java Island for the logistic purposes. The bridge was retrofitted 26 years into its life by adding two strips of carbon fiber reinforced polymer (CFRP) due to excessive cracks observed in the beams. Non-destructive field measurements were compared against a detailed finite element analysis of the structure to predict the performance of the girder in terms of deflection and moment capacity before and after the retrofitting work. The analysis was also used to predict the long-term deflections of the structure due to creep, crack distribution, and the ultimate moment capacity of the individual girder. Moreover, the finite element analysis was used to predict the deflection behavior of the overall bridge due to vehicle loading. Good agreement was obtained between the field measurement and the analytical study. A new service life of the structure considering the corrosion and new vehicle demand is carried out based on field measurement using non-destructive testing. Not only are the specific results beneficial for the Indonesian port authority as the stakeholder to manage this structure, but the approach detailed also paves the way for more efficient evaluation of bridges more generally over their service life.

Experimental and Analytical Study of Coriolis Effects in Bladed Disk

2015 ◽  
Author(s):  
Valentina Ruffini ◽  
Christoph Schwingshackl ◽  
Jeff Green
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Measurement Data ◽  
Travelling Wave ◽  
Experimental Results ◽  
Mode Shapes ◽  
Element Analysis ◽  
Coriolis Effects ◽  
Gyroscopic Effects ◽  
Gyroscopic Coupling

Modern aero-engines have reached a high level of sophistication and only significant changes will lead to the improvements necessary to achieve the economic and environmental targets of the future. Open rotors constitute a major leap in this direction, both in terms of efficiency and of technological innovation. This calls for a revision of the accepted design practices, and a new focus on phenomena that have been little investigated in the past, such as the Coriolis effect, or the gyroscopic coupling of the blades with the shaft. Experimental results from modern fans, with large blades and strong stagger angles, are showing dependence on Coriolis gyroscopic effects already, an effect that is expected to be strongly enhanced with the proposed open rotor designs. For an accurate prediction of the Coriolis and gyroscopic effects in rotating assemblies a fully experimentally validated approach is needed. Today’s FE models can capture the basic physical phenomena, but experimental confirmation is still needed for the evolution of the mode shapes with angular speed, and the influence of damping and geometric nonlinearities when gyroscopic coupling is considered. To support this validation effort a new rotating test rig will be introduced, initial measurement data will be discussed, and a comparison with a finite element analysis presented. Different forcing patterns, including forward and backward travelling-wave engine order excitation could be experimentally excited in the new rig, Coriolis-induced frequency splits were found in the dynamic response, showing a significant change in the dynamic behaviour of the investigated dummy disk, and only a minor impact of the mistuning was observed on the frequency splits due to Coriolis effects. The experimental results have been compared to a finite element analysis, and after some updating a good agreement between the predicted and measured Campbell diagrams could be obtained, demonstrating the reliability of the modelling approach.

scholarly journals Bayesian Prediction of Pre-Stressed Concrete Bridge Deflection Using Finite Element Analysis

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4956
Author(s):  
Jaebeom Lee ◽  
Kyoung-Chan Lee ◽  
Sung-Han Sim ◽  
Junhwa Lee ◽  
Young-Joo Lee
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Prediction Models ◽  
Measurement Data ◽  
Element Model ◽  
Time Dependent ◽  
Probabilistic Prediction ◽  
Element Analysis ◽  
Actual Measurement ◽  
Railway Bridges

Vertical deflection has been emphasized as an important safety indicator in the management of railway bridges. Therefore, various standards and studies have suggested physics-based models for predicting the time-dependent deflection of railway bridges. However, these approaches may be limited by model errors caused by uncertainties in various factors, such as material properties, creep coefficient, and temperature. This study proposes a new Bayesian method that employs both a finite element model and actual measurement data. To overcome the limitations of an imperfect finite element model and a shortage of data, Gaussian process regression is introduced and modified to consider both, the finite element analysis results and actual measurement data. In addition, the probabilistic prediction model can be updated whenever additional measurement data is available. In this manner, a probabilistic prediction model, that is customized to a target bridge, can be obtained. The proposed method is applied to a pre-stressed concrete railway bridge in the construction stage in the Republic of Korea, as an example of a bridge for which accurate time-dependent deflection is difficult to predict, and measurement data are insufficient. Probabilistic prediction models are successfully derived by applying the proposed method, and the corresponding prediction results agree with the actual measurements, even though the bridge experienced large downward deflections during the construction stage. In addition, the practical uses of the prediction models are discussed.

Finite Element Analysis of Cartridge Tapered Roller Bearing of Freight Wagon

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Parbant Singh ◽  
S.P. Harsha
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Roller Bearing ◽  
Element Analysis ◽  
Tapered Roller Bearing ◽  
Roller Bearings ◽  
Standard Design ◽  
Rail Industry ◽  
Tapered Roller ◽  
Tapered Roller Bearings

Freight trains run under high service loads during consignment loading and operation so tapered roller bearings are ideally suited to wheel bearing applications. The tapered roller bearings used in the railway industry are of a standard design fixed by the American Association of Railroads regulations. Nowadays rail industry improves the train operating speeds, which means that failure of a bearing will result into a derailment, affecting human lives, network disruption, and damage to the railroad, unplanned maintenance costs, and generating fear in general public about rail transport. So the rail industry has focused on the improvement in maintenance work and improvement in component design. This paper discusses the results of finite element analysis and model analysis of Cartridge Tapered Roller bearing (CTRB). Solid modelling of CTRB has been done using solid works. The CTRB is then discretized using ANSYS software and 3D hexahedral solid elements are used to mesh the components. The effect of vibration modes on the dynamic behaviour and stability of wagon is described. Frequencies up to a range of 100 Hz are considered for mode shapes.

Hyper-Can: An Automated Design and Analysis Tool for Packaging-Specific Applications

1994 ◽  
Author(s):  
Nila D. Bhakuni ◽  
Robert E. Dick ◽  
Kurt A. Beiter
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Integrity ◽  
Analysis Tool ◽  
Structural Constraints ◽  
Element Analysis ◽  
Volume Calculation ◽  
Analysis Process ◽  
Standard Design ◽  
Metal Volume

Abstract The objective of beverage and food can design is to minimize cost while maintaining structural integrity. The package must satisfy requirements of internal pressure, drop pressure, and axial column load. Finite element analysis allows the designer to examine these structural constraints before prototypes are created so a larger design space can be examined in a shorter time. Hyper-Can was created as a tool in the Macintosh environment to automate the design and analysis process and reduce the design cycle time in a user-friendly way. Hyper-Can contains templates or families of designs of standard beverage and food can ends and bodies that calculate geometric information for finite element analysis pre-processing and fill and metal volume calculation using external Fortran code. Hyper-Can allows the designer to manipulate a standard design from the conceptual stage to analysis utilizing a simple graphical interface on the Macintosh.

Forensic Estimation of Uplift of an Anchored Tank During the 2011 Earthquake Off the Pacific Coast of Tohoku

2019 ◽  
Author(s):  
Yuichi Yoshida ◽  
Tomoyo Taniguchi ◽  
Teruhiro Nakashima ◽  
Ken Hatayama
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pacific Coast ◽  
Time History ◽  
Calculation Methods ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
The Pacific ◽  
Anchor Bolts

Abstract The reconnaissance just after the 2011 earthquake off the Pacific coast of Tohoku reported the pulling out of anchor bolts of an upright cylindrical tank. Regarding the tank as an unanchored tank and employing the accelerogram recorded at 2 km off the tank, uplift of the unanchored tank during the 2011 earthquake off the Pacific coast of Tohoku was forensically examined. The time history of the uplift displacement of the tank computed by the explicit finite element analysis reveals that the unanchored tank uplifts during the earthquake and its uplift displacement is more than the length of the pulling out of the anchor bolts found by the reconnaissance. This implicitly corroborates applicability of the explicit finite element analysis to analyzing the tank rocking behavior. In addition to that, the uplift displacement of the unanchored tank was estimated by some calculation methods available to date and compared with that computed by the explicit finite element analysis. Comparison reveals that the calculation methods used herein may likely overestimate the uplift displacement of the unanchored tank and need to improve their calculation accuracy.

The Finite Element Analysis of Mechanical Behavior of New Connection

2014 ◽  
Vol 1065-1069 ◽  
pp. 1281-1284
Author(s):  
Chun Gang Wang ◽  
Xu Wang ◽  
Guo Chang Li ◽  
Jin Guo Wu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Behavior ◽  
New Wave ◽  
Calculation Methods ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Simulation Results ◽  
Vibration Wave ◽  
Better Than

Purlin connections have important influence on the stiffness, bearing capacity and the purlin calculation methods. A new kind of purlin connection was put forward in this paper. The mechanical behavior of the new connection was studied by finite element analysis using software ANSYS. As can be seen from the simulation results, the new connection can enhance the stiffness of purlin, and effect of each new wave connection is better than the promotion of purlin stiffness in the vibration wave connection. New connection has a better promotion effect for small stiffness of purlin.

scholarly journals INVESTIGATION OF DISPLACEMENT CONTROL EFFECT OF DIFFERENT AUXILIARY METHODS ON THE BASIS OF MEASUREMENT DATA AND FINITE ELEMENT ANALYSIS

2008 ◽  
Vol 64 (3) ◽  
pp. 473-484
Author(s):  
Hiroyuki ARAKI ◽  
Koji MITANI ◽  
Keiji YASUDA ◽  
Seigo TAKASHITA ◽  
Hidenori YOSHIDA ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Measurement Data ◽  
Displacement Control ◽  
Control Effect ◽  
Element Analysis
Sign in / Sign up

Export Citation Format

Share Document