Study on Time-Variant Robustness Assessment Method of Complex Bridges

2011 ◽  
Vol 250-253 ◽  
pp. 1962-1965
Author(s):  
Jin Song Zhu ◽  
Jian Song
Keyword(s):  
Assessment Method ◽  
Haihe River ◽  
Strength Factor ◽  
Finite Element Software ◽  
Structure Degradation ◽  
Degradation Rates ◽  
Close Relationship ◽  
Live Loads ◽  
Reserve Strength ◽  
Robustness Assessment

In order to accurately assess the robustness of the complex bridge structure, a method of robustness assessment that takes structure degradation and accidental loads into consideration is proposed. Firstly, the degradation rates of member section properties and the increasing rate of live load are set as variables. The parametrical model of structure is established by the finite element software of ANSYS. Secondly, the structure robustness is based upon analysis from the robustness index, the reserve strength factor and the residual strength factor. The effects of three degradation rates of section properties, the established increasing rate of live loads and accidental loads on the robustness of bridges are considered. Finally, this method is used to analyze the time-variant robustness of Guotai Bridge located on the Haihe River of Tianjin. The results indicate that different degradation rates of member section properties have different effect on the robustness of Guotai Bridge, the effect of accidental loads has a close relationship with its acting position.

An intelligent performance degradation assessment method for bearings

2016 ◽  
Vol 23 (18) ◽  
pp. 3023-3040 ◽  
Author(s):  
Huiming Jiang ◽  
Jin Chen ◽  
Guangming Dong ◽  
Ran Wang
Keyword(s):  
Evaluation System ◽  
Health Management ◽  
Feature Space ◽  
Assessment Method ◽  
Performance Degradation ◽  
Accelerated Life Test ◽  
Time Data ◽  
Accelerated Life ◽  
Rolling Element ◽  
Close Relationship

Bearings are one of the most frequently used components in the rotatory machinery, so the performance degradation assessment of bearings plays an important role in the prognostics and health management of systems. Hidden Markov model (HMM) is a widely applied data-driven model used for bearing performance degradation assessment and has many successful applications. A normal HMM needs to be trained in advance, which has close relationship with the evaluation system. However, the trained HMM is quite influenced by many issues, such as the data integrity and the feature space. In this paper, an intelligent bearing performance degradation assessment method based on HMM and nuisance attribute projection (NAP) is proposed. The proposed method can combine the information from the experimental data and the real-time data effectively and assess the performance since the beginning of the monitoring. The effectiveness of the proposed method is verified through an accelerated life test of rolling element bearings.

Replacement of reinforced concrete deck of Champlain Bridge, Montreal, by orthotropic steel deck

1996 ◽  
Vol 23 (6) ◽  
pp. 1341-1349 ◽  
Author(s):  
G. P. Carlin ◽  
M. S. Mirza
Keyword(s):  
Reinforced Concrete ◽  
Highway Bridges ◽  
Orthotropic Steel Deck ◽  
Strength Capacity ◽  
Live Loads ◽  
Base Course ◽  
Steel Panels ◽  
Reserve Strength ◽  
Concrete Deck ◽  
Steel Deck

The Champlain Bridge, Montreal, Quebec, has recently undergone replacement of its deteriorated reinforced concrete deck situated over the St. Lawrence Seaway with a new orthotropic steel deck. The new deck consists of 210 prefabricated steel panels which have been installed at the rate of one panel per night. The panels arrived on site with a base course of pavement to allow traffic flow over the new panels without disrupting the rush hour and daytime traffic. As a result of the new deck being 25% lighter in weight, the reserve strength capacity of the steel superstructure to accommodate live loads has increased sufficiently to bring the bridge within the governing live load requirements of the CAN/CSA Standard S6-1988 "Design of highway bridges." The governing design live loads on bridges have increased by about 50% since the original construction of the bridge over 30 years ago and reflect the larger vehicle weights permitted over Canadian roadways. Key words: alternative deck systems, cantilevered steel superstructure, closed rib stiffeners, counterweights, diaphragms, field erection, orthotropic plate deck, prefabrication, reinforced concrete, welding.

Behaviour of partly stiffened cold-formed steel built-up beams: Experimental investigation and numerical validation

2018 ◽  
Vol 22 (1) ◽  
pp. 172-186 ◽  
Author(s):  
M Adil Dar ◽  
N Subramanian ◽  
A R Dar ◽  
M Anbarasu ◽  
James BP Lim ◽  
...  
Keyword(s):  
Failure Modes ◽  
Numerical Study ◽  
Local Buckling ◽  
Steel Structures ◽  
Vital Role ◽  
Steel Beams ◽  
Design Strength ◽  
Finite Element Software ◽  
Cold Formed Steel ◽  
Reserve Strength

To address the various instability problems in cold-formed steel members, many researchers have mainly focused on developing innovative sectional profiles wherein geometry of the section plays a vital role in enhancing the inherent resistance of such sections against premature buckling. However, the process of forming such innovative shapes is not only complex and time-consuming but sometimes such sections fail to mobilize their complete reserve strength. Hence, a stiffening arrangement of weaker zones for mobilizing the untapped reserve strength is suggested. The contribution of this simple, effective and partly stiffening arrangements, aimed at eliminating/delaying the premature local buckling, is studied both experimentally and numerically and also compared with existing codes. Experimental study was carried out on different simply supported cold-formed steel beams with judiciously proposed stiffening arrangements under four-point loading. An equivalent hot-rolled steel beam was also tested to compare the efficiency of the cold-formed steel beams. The cold-formed steel beams investigated had different width-to-thickness ratio, different geometries and different stiffening arrangements. The test strengths, failure modes, deformed shapes, load versus mid-span displacements and geometric imperfections were measured and reported. The test strengths of the beam models are also compared with the design strength predicted by North American Standards and Eurocode for cold-formed steel structures. To validate the test results further, a numerical study was carried out on such stiffened cold-formed steel beams using finite element software ABAQUS. All these results show that the proposed strengthening system is efficient and economical and allow cold-formed steel beams to reach greater load carrying capacity.

Vibration Response Analysis on Deep-Water Piers under Earthquake and Wave Coupling Motivation

2014 ◽  
Vol 548-549 ◽  
pp. 1607-1612
Author(s):  
Zi Jian Wang ◽  
Li Ming Wu ◽  
Sheng Xie Xiao
Keyword(s):  
Hydrodynamic Pressure ◽  
Internal Force ◽  
Response Analysis ◽  
Computing Platform ◽  
Finite Element Software ◽  
Continuous Beam Bridge ◽  
Rigid Frame ◽  
Close Relationship ◽  
Beam Bridge ◽  
Rigid Frame Bridge

Taking a typical cylindrical solid pier as example, this paper utilizes the way of additional mass to consider the influences of hydrodynamic pressure on piers. It establishes dynamic response comparative analysis of single pier model under different earthquakes’ motivation taking ANSYS finite element software as computing platform. This draws conclusion that hydrodynamic pressure keeps characteristics of changing the seismic response of piers in which pier top displacement and pier bottom internal force are increased. Also it acquires the conclusion that weight and cycle of structure are related to the effect of hydrodynamic pressure. Through analyzing continuous beam bridge and continuous rigid-frame bridge, it is verified that there exists close relationship between effect of hydrodynamic pressure and inherent cycle of structure in which the higher inherent cycle becomes, the lower influence hydrodynamic pressure keeps on structure.

Probabilistic assessment method of the non-monotonic dose-responses-Part II: Robustness assessment

2017 ◽  
Vol 110 ◽  
pp. 214-228 ◽  
Author(s):  
Grégoire Chevillotte ◽  
Audrey Bernard ◽  
Clémence Varret ◽  
Pascal Ballet ◽  
Laurent Bodin ◽  
...  
Keyword(s):  
Assessment Method ◽  
Probabilistic Assessment ◽  
Dose Responses ◽  
Robustness Assessment

Minding the Close Relationship

1999 ◽  
Author(s):  
John H. Harvey ◽  
Julia Omarzu
Keyword(s):  
Close Relationship

Delir-Diagnostik

2007 ◽  
Vol 20 (2-3) ◽  
pp. 135-139
Author(s):  
B. Dittrich ◽  
G. Gatterer ◽  
T. Frühwald ◽  
U. Sommeregger
Keyword(s):  
Confusion Assessment Method ◽  
Assessment Method ◽  
Psychische Störung ◽  
Confusion Assessment

Zusammenfassung: Das Delir (“akuter Verwirrtheitszustand”) bezeichnet eine psychische Störung, die plötzlich auftritt, durch eine rasche Fluktuation von Bewusstseinslage und Aufmerksamkeitsleistung gekennzeichnet ist und eine organische Ursache hat. Dieses Störungsbild nimmt bei Patienten im höheren Lebensalter deutlich an Häufigkeit zu und verursacht durch verlängerte Krankenhausaufenthalte und ungünstige Krankheitsverläufe erhebliche Kosten im Gesundheitssystem. Daher erscheint eine möglichst frühe Erkennung deliranter Zustandsbilder gerade im Rahmen der Geriatrie von großer Bedeutung. Zu diesem Zweck wurde eine deutsche Version der international weit verbreiteten Confusion Assessment Method entwickelt, die für die Bedürfnisse einer Abteilung für Akutgeriatrie modifiziert wurde. Dargestellt werden die Entwicklung und erste Erfahrungen mit diesem Instrument.

The Need Inventory of Sensation Seeking (NISS)

2012 ◽  
Vol 28 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Marcus Roth ◽  
Philipp Hammelstein
Keyword(s):  
Sensation Seeking ◽  
Reliability And Validity ◽  
Assessment Method ◽  
Factorial Structure ◽  
Conventional Methods ◽  
New Research ◽  
Sensation Seeking Scale ◽  
Temperamental Trait ◽  
Nonclinical Study

Based on the conception of sensation seeking as a need rather than a temperamental trait ( Hammelstein, 2004 ), we present a new assessment method, the Need Inventory of Sensation Seeking (NISS), which is considered to assess a motivational disposition. Three studies are presented: The first examined the factorial structure and the reliability of the German versions of the NISS; the second study compared the German and the English versions of the NISS; and finally, the validity of the NISS was examined in a nonclinical study and compared to the validity of conventional methods of assessing sensation seeking (Sensation Seeking Scale – Form V; SSS-V). Compared to the SSS-V, the NISS shows better reliability and validity in addition to providing new research possibilities including application in experimental areas.

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