Thermal loading of concrete bridges

1984 ◽  
Vol 11 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Malcolm J. S. Hirst
Keyword(s):  
Solar Radiation ◽  
Engineering Design ◽  
Computer Model ◽  
Parametric Study ◽  
Structural Engineering ◽  
Thermal Loading ◽  
Design Method ◽  
Field Measurements ◽  
Concrete Bridges ◽  
Frequency Distributions

This paper presents the results of a parametric study into the thermal loading of concrete bridges by solar radiation. All results were obtained using a computer model calibrated from field measurements. The model computes the loading parameters from the bridge characteristics and the standard daily records of the weather bureau. The design method given uses an effective thickness concept to find the effects of a wearing course on the temperature profile of the underlying bridge. Thermal loading depends on climate and is extremely variable. Histograms are presented, which show the frequency distributions of the loading parameters for sample bridges at three Australian sites covering a range of climatic regimes from tropical to temperate. Key words: bridges, concrete, loads, temperature, solar radiation, structural engineering, design chart.

Simple Approach to Calculate Displacements and Rotations in Integral Abutment Bridges

2015 ◽  
Vol 2522 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Suhail Albhaisi ◽  
Hani Nassif
Keyword(s):  
Parametric Study ◽  
Thermal Loading ◽  
Three Dimensional ◽  
Field Measurements ◽  
Simple Approach ◽  
Fe Model ◽  
Integral Abutment ◽  
Foundation Soil ◽  
Integral Abutment Bridges ◽  
Abutment Bridges

This paper presents a simple approach to calculate the displacements and the rotations induced by thermal loading in integral abutment bridges (IABs). The approach was derived from the results of a parametric study that investigated the effect of substructure stiffness on the performance of short- and medium-length steel IABs built on clay and sand under thermal load effects. Various parameters, such as pile size and orientation, pile material, and foundation soil stiffness, were considered in the study. Detailed three-dimensional (3-D) finite element (FE) models using the software LUSAS were developed to capture the overall behavior of IABs. The developed 3-D FE model was calibrated with field measurements obtained from a previous study. A parametric study was carried out with the calibrated models to study the effects of the above parameters on the performance of IABs under thermal loading using the AASHTO load and resistance factor design temperature ranges. The study showed that most parameters have significant effects on the displacement and rotation of the abutment and the supporting piles. Also, for relatively wide IABs, there were significant variations in the displacement and rotations in the substructure elements between interior and exterior locations. This approach, which used simple equations and charts and included parameters such as the length of the bridge, the stiffness of the foundation soil, and the pile location, provided results that were comparable with those of a detailed FE analysis.

Parametric study of the effects of arctic soot on solar radiation

1982 ◽  
Vol 16 (6) ◽  
pp. 1365-1371 ◽  
Author(s):  
William M. Porch ◽  
Michael C. MacCracken
Keyword(s):  
Solar Radiation ◽  
Parametric Study

Structural engineering design of carbon dots for lubrication

2021 ◽  
Author(s):  
Chuang He ◽  
Shuang E ◽  
Honghao Yan ◽  
Xiaojie Li
Keyword(s):  
Engineering Design ◽  
Carbon Dots ◽  
Structural Engineering

Random impact FEM simulation of irregularly-shaped media for parametric study of vibratory surface enhancement

2021 ◽  
pp. 095440542199012
Author(s):  
Jing Zhang ◽  
Joselito Yam Alcaraz ◽  
Swee-Hock Yeo ◽  
Arun Prasanth Nagalingam ◽  
Abhay Gopinath
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Parametric Study ◽  
Thermal Loading ◽  
Low Cycle Fatigue ◽  
Fem Simulation ◽  
Surface Finishing ◽  
Aerospace Materials ◽  
Surface Enhancement ◽  
Steel Balls

Aerospace materials experience high levels of mechanical and thermal loading, high/low cycle fatigue, and damage from foreign objects during service, which can lead to premature retirement. Mechanical surface treatments of metallic components, for example, fan blades and blisks, are proven to improve fatigue life, improve wear resistance and avoid stress corrosion by introducing work hardening, compressive residual stresses of sub-surface, and surface finishing. Vibropeening can enhance aerospace materials’ fatigue life involving the kinetic agitation of hardened steel media in a vibratory finishing machine that induces compressive stresses into the component sub-layers while keeping a finished surface. Spherical steel balls are the most widely used shape among steel-based media and have been explored for decades. However, they are not always versatile, which cannot access deep grooves, sharp corners, and intricate profiles. Steel ballcones or satellites, when mixed with round steel balls and other steel media (diagonals, pins, eclipses, cones), works very well in such areas that ball-shaped media are unable to reach. However, a methodology of study the effect of irregularly-shaped media in surface enhancement processes has not been established. This paper proposes a finite element-based model to present a methodology for the parametric study of vibratory surface enhancement with irregularly-shaped media and investigates residual stress profiles within a treated area of an Inconel component. The methodology is discussed in detail, which involves a stochastic simulation of orientation, impact force, and impact location. The contrasting effects of a high aspect ratio, or an edge contact, as opposed to rounded and oblique contacts are demonstrated, with further analysis on the superposition of these effects. Finally, the simulation results are compared with actual residual stress measurements and was found to have a max percent difference of 34% up to 20 [Formula: see text]m below the media surface.

Einheitliches Querkraftmodell für Stahl- und Spannbetonbrücken – erweiterte Grundlagen/Uniform Shear Design Method for Existing Reinforced and Prestressed Concrete Bridges – Extended Background

Bauingenieur ◽  
2016 ◽  
Vol 91 (12) ◽  
pp. 487-495
Author(s):  
Martin Herbrand ◽  
Martin Classen ◽  
Alexander Stark ◽  
Dominik Kueres
Keyword(s):  
Prestressed Concrete ◽  
Design Method ◽  
Concrete Bridges ◽  
Prestressed Concrete Bridges ◽  
Shear Design ◽  
Uniform Shear

Während das Biegetragverhalten von Stahl- und Spannbetonbauteilen als gelöst angesehen wird, ist das Querkrafttragverhalten schubschlanker Bauteile nicht abschließend geklärt. Vor allem für die Beurteilung von Bestandsbauwerken sind aber Querkraftmodelle notwendig, die möglichst einfach anwendbar sind und dennoch ausreichend genaue und damit wirtschaftliche Vorhersagen der Tragfähigkeit erlauben. Ein einheitliches Querkraftmodell mit Betontraganteil für Stahl- und Spannbetonbauteile ermöglicht bei der Bemessung einen stetigen Übergang zwischen Bauteilen ohne und mit Querkraftbewehrung, wenn deren Betontraganteile für asw = 0 identisch sind. Der Vergleich mit den ACI-DAfStb-Querkraftdatenbanken belegt, dass ein solches Modell für Bauteile mit Querkraftbewehrung zu deutlich geringeren Streuungen und gleichzeitig einem höheren Sicherheitsniveau im Vergleich zum aktuellen EC2 führt. Insbesondere für Bauteile mit geringen Querkraftbewehrungsgraden ergeben sich hierdurch höhere rechnerische Tragfähigkeiten, was zum Beispiel für die Nachrechnung von Bestandsbauwerken wie Brücken von Vorteil ist. In diesem Beitrag werden die Hintergründe für einen konsistenten Übergang von einen Fachwerkmodell mit Betontraganteil zu einem Fachwerkmodell mit variabler Druckstrebenneigung erläutert.

Sign in / Sign up

Export Citation Format

Share Document