Nonlinear Random Response of Shallow Shells at Elevated Temperatures Using Finite Element Modal Method

2004 ◽  
Author(s):  
Xinyun Guo ◽  
Adam Przekop ◽  
Chuh Mei
Keyword(s):  
Finite Element ◽  
Elevated Temperatures ◽  
Random Response ◽  
Shallow Shells ◽  
Modal Method

Thermal Modeling of a Railroad Tapered-Roller Bearing Using Finite Element Analysis

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
Constantine M. Tarawneh ◽  
Arturo A. Fuentes ◽  
Javier A. Kypuros ◽  
Lariza A. Navarro ◽  
Andrei G. Vaipan ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surface Temperature ◽  
Elevated Temperatures ◽  
Roller Bearing ◽  
Fe Model ◽  
Element Analysis ◽  
Tapered Roller Bearing ◽  
Outer Race ◽  
Railroad Industry

In the railroad industry, distressed bearings in service are primarily identified using wayside hot-box detectors (HBDs). Current technology has expanded the role of these detectors to monitor bearings that appear to “warm trend” relative to the average temperatures of the remainder of bearings on the train. Several bearings set-out for trending and classified as nonverified, meaning no discernible damage, revealed that a common feature was discoloration of rollers within a cone (inner race) assembly. Subsequent laboratory experiments were performed to determine a minimum temperature and environment necessary to reproduce these discolorations and concluded that the discoloration is most likely due to roller temperatures greater than 232 °C (450 °F) for periods of at least 4 h. The latter finding sparked several discussions and speculations in the railroad industry as to whether it is possible to have rollers reaching such elevated temperatures without heating the bearing cup (outer race) to a temperature significant enough to trigger the HBDs. With this motivation, and based on previous experimental and analytical work, a thermal finite element analysis (FEA) of a railroad bearing pressed onto an axle was conducted using ALGOR 20.3™. The finite element (FE) model was used to simulate different heating scenarios with the purpose of obtaining the temperatures of internal components of the bearing assembly, as well as the heat generation rates and the bearing cup surface temperature. The results showed that, even though some rollers can reach unsafe operating temperatures, the bearing cup surface temperature does not exhibit levels that would trigger HBD alarms.

Finite element modeling of structural steel component failure at elevated temperatures

Structures ◽  
2016 ◽  
Vol 6 ◽  
pp. 134-145 ◽  
Author(s):  
Mina Seif ◽  
Joseph Main ◽  
Jonathan Weigand ◽  
Therese P. McAllister ◽  
William Luecke
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Structural Steel ◽  
Elevated Temperatures ◽  
Steel Component ◽  
Component Failure ◽  
Element Modeling

Finite element, large-deflection random response of thermally buckled beams

AIAA Journal ◽  
1990 ◽  
Vol 28 (12) ◽  
pp. 2125-2131 ◽  
Author(s):  
James Locke ◽  
Chuh Mei
Keyword(s):  
Finite Element ◽  
Large Deflection ◽  
Random Response ◽  
Buckled Beams

Steam Turbine Casing Analyses to Determine Pressure and Temperature Limits

2021 ◽  
Author(s):  
Paul T. Smith ◽  
Daniel J. Griffin
Keyword(s):  
Finite Element ◽  
Steam Turbine ◽  
Elevated Temperatures ◽  
Temperature Limit ◽  
Normal Operation ◽  
Working Pressure ◽  
Element Analysis ◽  
Minimum Width ◽  
Joint Contact ◽  
Joint Contact Pressure

Abstract To ensure safe and reliable operation, steam turbine casings must have acceptable stresses and maintain sealing when subjected to internal pressures and temperatures. To show turbine casings acceptable, analysts conduct structural evaluations using finite element analysis (FEA) techniques. This paper outlines the analytical methods used to perform these types of analyses, provides analysis examples, and summarizes the process to create pressure and temperature limit maps. Finite element models of the main casing and steam chest are used to determine stresses and sealing of the casing horizontal split line and steam chest cover during normal operation. The sealing evaluations consider the sealing capabilities of the bolted joints when the casing is subjected to internal steam pressure and consider the effects of bolt stress relaxation at elevated temperatures, joint contact surface separation, and penetration of the internal pressure into the sealing surface. The acceptance criteria for the bolted joint sealing is based on the minimum width of the contacting surface and the minimum joint contact pressure. A series of analyses were conducted on the various models to create pressure and temperature limit maps, so that the design can be applied for the appropriate conditions. These maps plot maximum allowable working pressure (MAWP) versus maximum allowable working temperature (MAWT), and allow an application engineer to easily determine the acceptability of the casing for a particular application. An explanation of the process used to create the limit maps is presented.

Random Response of a Sluice Gate Support

1991 ◽  
Author(s):  
W. Q. Feng ◽  
T. C. Huang ◽  
W. J. Liu ◽  
G. X. Dong
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Extended Finite Element Method ◽  
Linear Structure ◽  
Response Analysis ◽  
Random Response ◽  
Extended Finite Element ◽  
Sluice Gate ◽  
Excitation Field ◽  
Element Method

Abstract By the use of the extended finite element method the analysis of the random response of a linear structure to a continuous excitation field, random in time and space, is presented in this paper. The extended finite element method includes the formulation for obtaining the equivalent node force power spectrum. The corresponding computer program has been produced. A random response analysis of a sluice gate support shows satisfactory agreement with the experiment results.

scholarly journals A detailed investigation on thermal behaviour of slim floor beams with web openings at elevated temperatures

2019 ◽  
Vol 10 (4) ◽  
pp. 446-467
Author(s):  
Naveed Alam ◽  
Ali Nadjai ◽  
Olivier Vassart ◽  
Francois Hanus
Keyword(s):  
Finite Element ◽  
Thermal Behaviour ◽  
Elevated Temperatures ◽  
Major Influence ◽  
Web Openings ◽  
Content Type ◽  
Composite Action ◽  
Temperature Development ◽  
In Fire ◽  
Steel Section

Purpose In recent times, the use of steel sections with web openings has become common as slim floor beams because they offer a reduction in weight of the steelwork, accommodate services within the floor depth and provide the composite action. The composite action in these beams is achieved either through the concrete dowels or through concrete plugs. Though these web openings offer several benefits in slim floor beams, they induce the material discontinuity in the steel web, which may affect their shear capacity and/or thermal behaviour. The purpose of this study is to investigate the thermal behaviour of slim floor beams with web openings in fire. Design/methodology/approach This research presents findings from experimental and analytical investigations conducted to study the thermal behaviour of slim floor beams with web openings in fire. For this purpose, an experimental investigation was conducted, which shows that the presence of web openings has a major influence on temperature development across the steel section as well as along the span of these beams. The behaviour of the tested slim floor beam is validated using finite element modelling. The validated finite element model is then used to conduct a sensitivity study to analyse the influence of different opening spacings, sizes and shapes on the thermal performance of slim floor beams in fire. Findings Test results show that the presence of web openings has a major influence on temperature development across the steel section as well as along the span of these beams. Temperatures on the web below the openings are found to be higher as compared to those recorded on the adjacent solid steel web. It is also observed that temperatures on the steel web above the openings are lesser than those on the adjacent solid steel web. Parametric studies conducted using the verified analytical modelling methods show that different opening spacings, sizes and shapes have a variable impact on the thermal behaviour of slim floor beams in fire. Closely spaced and larger opening sizes were found to have a more severe influence on their thermal behaviour in fire as compared to widely spaced and smaller openings. It was also found that the behaviour of these beams is influenced by the shape of the openings with rectangular openings resulting in more severe thermal distributions as compared to circular openings. Originality/value The findings from this research study are highly valuable as they contribute to the existing knowledge database. There is a lack of experimental and analytical investigation on performance of slim floor beams with web openings at elevated temperatures. The results and conclusions from this study will help in developing innovative designs for slim floor beams and will help in reducing the fire related risk associated with structures comprising of slim floor beams with web openings.

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