High-cycle fatigue tests of pretensioned concrete beams

PCI Journal ◽  
2022 ◽  
Vol 67 (1) ◽  
Author(s):  
Jörn Remitz ◽  
Martin Empelmann
Keyword(s):  
Fatigue Life ◽  
High Cycle Fatigue ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Design Methods ◽  
Test Results ◽  
Cycle Fatigue ◽  
Pretensioned Concrete ◽  
Current Design

Pretensioned concrete beams are widely used as bridge girders for simply supported bridges. Understanding the fatigue behavior of such beams is very important for design and construction to prevent fatigue failure. The fatigue behavior of pretensioned concrete beams is mainly influenced by the fatigue of the prestressing strands. The evaluation of previous test results from the literature indicated a reduced fatigue life in the long-life region compared with current design methods and specifications. Therefore, nine additional high-cycle fatigue tests were conducted on pretensioned concrete beams with strand stress ranges of about 100 MPa (14.5 ksi). The test results confirmed that current design methods and specifications overestimate the fatigue life of embedded strands in pretensioned concrete beams.

Technology of the 1990s: advanced materials and predictive design

1987 ◽  
Vol 322 (1567) ◽  
pp. 393-407 ◽  
Keyword(s):  
Material Properties ◽  
Design Methods ◽  
Advanced Materials ◽  
Additional Insight ◽  
Atomistic Modelling ◽  
Continuum Modelling ◽  
Engineering Problems ◽  
Current Design ◽  
Predictive Design ◽  
Insight Into

The demands made on materials in contemporary design are increasingly stringent. Materials and design methods have evolved to meet them. However, it is proving increasingly difficult to extend current design methods, largely based on continuum modelling and empiricism, to cope with the larger number of variables that appear in many engineering applications. It is argued that atomistic modelling (which, by itself, seldom leads to engineering solutions) can give additional insight into the form of constitutive equations, the grouping of variables, and the magnitudes of material properties. Properly interpreted, this information can point the way to a ‘model-informed ' empiricism that can help solve pressing engineering problems.

Internal forces in segmental tunnel linings—a comparison between current design methods

2014 ◽  
Vol 50 (2) ◽  
pp. 326-334 ◽  
Author(s):  
N. A. Do ◽  
D. Dias ◽  
P. P. Oreste ◽  
I. Djeran-Maigre
Keyword(s):  
Design Methods ◽  
Current Design ◽  
Internal Forces

scholarly journals Performance of soil nails in Dublin glacial till

2008 ◽  
Vol 45 (12) ◽  
pp. 1685-1698 ◽  
Author(s):  
Christopher O. Menkiti ◽  
Michael Long
Keyword(s):  
Large Scale ◽  
Design Methods ◽  
Glacial Till ◽  
Deformation Pattern ◽  
Soil Nailing ◽  
Short Term ◽  
Soil Nail ◽  
Design Procedures ◽  
Temporary Support ◽  
Current Design

Soil nailing is being used in many projects in glacial tills in Ireland, particularly to provide temporary support to steep slopes. Little design guidance is available for such materials, and it is known that the application of design procedures developed for other material is conservative. Detailed nail instrumentation and field monitoring has been undertaken during large-scale soil nailing works for the Dublin Port Tunnel project. It was found that the short-term behaviour of nails was the reverse of that assumed in current design methods. Most of the load was induced as a results of drilling and nailing the lift immediately below the nail being monitored rather than due to excavation-induced stress relief. The highest forces were developed in the upper nails where the largest ground movements occurred. This is the reverse of most current design methods where the highest soil–nail bond is assigned to the deepest nails. It seems that the observed short-term, prefailure behaviour of nailed slopes is governed more by the deformation pattern of the slope than by large-scale development of failed wedges. Current design procedures should be reviewed. Despite this, the trial confirmed that the currently used procedures are highly conservative for Dublin glacial till.

Relevant methods in costume design in the context of the culture of Postmodern

Servis plus ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 45-56
Author(s):  
Дарья Ермилова ◽  
Darya Ermilova
Keyword(s):  
Costume Design ◽  
Design Methods ◽  
Design History ◽  
Modern Project ◽  
Diverse Environment ◽  
Current Design ◽  
History Of ◽  
The One ◽  
Relationship Of ◽  
Professional Disciplines

The article is dedicated to the analysis of design methods in modern design being related with postmodernism aesthetics. Subject of research – is creative design methods. The aim of the study is to examine the methods characteristic of postmodern culture, which are used in the costume design. The hypothesis of the study – is typical interpretation methods of the tradition in postmodern – eclectic, collage (the method of citations), citation, deconstruction, parody, ironic pastiche, vintage, and used in costume design. The study used the cultural studies approach, considering modern project activities as a part of the culture of postmodernism, a systematic approach that allows revealing the relationship of aesthetic theories with practice, the specific design, aesthetic approach in the analysis of the characteristics of postmodernism, art analysis for costume design. It is proved that the modern costume designers are actively using methods of postmodernism that allow you to create a diverse environment reflecting the changing and diverse needs of man. Analysis of design practice in the context of postmodernism allowed to reveal when the costume design together with General cultural processes were first analyzed design methods in costume design which related to the category of comic – ironic pastiche, parody, playing with meanings, techniques of wit, considered in connection with other methods of postmodernism: eclectic, a collage, a transgression. The study of current design methods in costume design, on the one hand, complements insufficiently explored area in the theory of design. On the other hand, the results of the study can be used in curriculum development and teaching of professional disciplines profile “costume Design” directions 54.03.01 Design – costume design, history of design, history of fashion houses. In the future will be explored current design methods in costume design related to environmental aesthetics.

Performance of lapped splices in reinforced concrete loaded beyond yielding of the steel

1978 ◽  
Vol 5 (4) ◽  
pp. 489-496 ◽  
Author(s):  
Telvin Rezansoff
Keyword(s):  
Reinforced Concrete ◽  
Yield Strength ◽  
Strain Hardening ◽  
Yield Stress ◽  
Design Methods ◽  
Repeated Loading ◽  
Reinforcing Steel ◽  
Lap Splice ◽  
Load Cycling ◽  
Current Design

Eighteen beams designed to fail in the lap splice after reaching yield of the reinforcing steel were tested under either a single load application or low cycle repeated loading. Splice lengths were varied from well below code requirements up to approximately those required by current codes and design methods. Performance was studied on the basis of the ductility exhibited prior to failure and the influence of load cycling and stress–strain characteristics of the reinforcing steel. No confinement (stirrups or a spiral) was provided to the splice.Comparison is made with common lap splice design methods. These assume that the beam will respond adequately and the splice will not fail prematurely if the splice length is made long enough to withstand a steel stress 25% above the normal yield strength of the reinforcing steel. The detrimental effects on ductility of higher than nominal yield stress and of strain hardening at relatively low strains for the grade 60 (nominal yield stress = 60 ksi (414 MPa)) deformed reinforcing steel used are noted. The possible weakness of using nominal yield strengths for the reinforcing steel with current design methods is emphasized.

Large-scale pile tests in Mercia mudstone: Data analysis and evaluation of current design methods

2003 ◽  
Vol 21 (3) ◽  
pp. 167-200 ◽  
Author(s):  
J. R. Omer ◽  
J. R. Omer ◽  
R. B. Robinson ◽  
R. Delpak ◽  
J. K. C. Shih
Keyword(s):  
Data Analysis ◽  
Large Scale ◽  
Design Methods ◽  
Analysis And Evaluation ◽  
Current Design

The aerodynamic installation of optical fibres in telecommunication networks

2002 ◽  
Vol 216 (4) ◽  
pp. 193-205
Author(s):  
D A McNeil ◽  
A J Addlesee ◽  
J Taylor
Keyword(s):  
Fluid Mechanics ◽  
Tube Wall ◽  
Design Methods ◽  
Telecommunication Networks ◽  
New Method ◽  
Optical Fibres ◽  
Air Drag ◽  
Stress Levels ◽  
Current Design ◽  
Technological Developments

The installation of optical fibres for communication purposes is increasingly being carried out using a blowing technique. This study reviews the basis of the current design methods for this technique and proposes a new method based on a more traditional fluid mechanics approach. The method is used to demonstrate how far optical fibres can be blown and the stress levels likely to be encountered by them at various positions within their journey. The method will allow for future technological developments to be simulated by allowing for air drag on the fibre and the constraining tube wall to be treated differently.

State of the Practice for Design of Groups of Laterally Loaded Drilled Shafts

2000 ◽  
Vol 1736 (1) ◽  
pp. 33-40
Author(s):  
Kenneth D. Walsh ◽  
Daniel N. Fréchette ◽  
William N. Houston ◽  
Sandra L. Houston
Keyword(s):  
Design Procedure ◽  
Reduction Factor ◽  
Design Methods ◽  
Drilled Shafts ◽  
Deep Foundations ◽  
Clear Understanding ◽  
Subgrade Reaction ◽  
Modulus Of Subgrade Reaction ◽  
Current Design ◽  
Laterally Loaded

Many state departments of transportation (DOTs) are beginning to use a larger percentage of drilled shafts for their deep foundations. Therefore, a clear understanding of current design methodology and specifications is important. The three most common design methods in use today are the group reduction factor, the p-multiplier method, and the modulus of subgrade reaction multiplier. A brief discussion of each method is presented. Telephone interviews were conducted with state DOTs to determine their current design procedure for groups of laterally loaded drilled shafts. Responses were obtained from all 50 states. Additional interviews were conducted with several well-known researchers in the field of deep foundations to determine what procedure they recommend. From these interviews it was clear that there is no uniformity in design methods or even in interpretation of the AASHTO recommendations for laterally loaded drilled shaft groups. The different interpretations of the AASHTO recommendations may be due to wording used in the AASHTO specifications, namely, the “ratio of lateral resistance of shaft in group to single shaft.” It is somewhat unclear as to whether this wording refers to the single-pile capacity or to the soil resistance. To understand the intended method of application of these factors, a historical search of the literature was conducted. It is clear that the source cited in the AASHTO specifications recommended using the reduction factors to reduce the modulus of subgrade reaction.

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