scholarly journals Experimentally Validated Nonlinear Analysis of Bridge Plate Girders with Deformations

2015 ◽  
Vol 37 (3) ◽  
pp. 53-61 ◽  
Author(s):  
Mieszko Kużawa ◽  
Jan Bień
Keyword(s):  
Nonlinear Analysis ◽  
Load Capacity ◽  
Shear Capacity ◽  
Shear Load ◽  
Structural Behaviour ◽  
Plate Girders ◽  
Bridge Plate ◽  
Experimental Laboratory ◽  
The University

Abstract Comprehensive methodology of numerical nonlinear analysis of the consecutive phases in the structural behaviour of bridge plate girders with deformations is presented. The analysis concerns all stages of structure loading until failure and especially determination of the ultimate shear load capacity. Verification and validation of the numerical procedures proposed is based on comparison of the calculated results with effects of experimental laboratory shear capacity tests of plate girders carried out at the University of Ljubljana.

scholarly journals A Forensic Engineering Investigation Of a Ladder Failure

2009 ◽  
Vol 26 (2) ◽  
Author(s):  
Nicholas A. Petrucci
Keyword(s):  
Load Capacity ◽  
National Standards ◽  
Shear Load ◽  
Improper Use ◽  
Forensic Engineering ◽  
Left Front ◽  
Engineering Investigation

A Worker (Plaintiff) Fell From A Step-Ladder And Was Injured. The Purpose Of The Forensic Engineering Investigation Was To Determine The Cause(S) Of The Incident, And In Particular, If The Incident Was Caused By A Ladder Defect. The Incident Ladder And A Representative Incident Scene Were Inspected. Various Discovery Documents And The Applicable American National Standards Institute (Ansi) Standard Were Reviewed. A Critique From The Opposing (Defendant) Expert Is Presented And Addressed. The Cause Of The Plaintiff Fall From The Ladder Was Determined To Be Its Sudden Instability Due To The Failure Of A Rivet That Secured The Top Cap To The Left-Front Rail. The Failed Rivet Was Not Recovered. Further Analysis Indicated That The Cause Of The Rivet Failure Was Its Defective Design Coupled With Its Reduction In Shear Load Capacity From Normal And Improper Use Of The Ladder. The Determination Of The Defective Design Of The Rivet Was Confirmed By Subsequent Design Improvements Of The Ladder. The Relevance Of The Analysis Performed Is Discussed. Various Noteworthy Points Are Presented For Consideration For Forensic Engineers Of Various Technical Disciplines.

scholarly journals Shear Cap Size Selection Method Based on Parametric Analysis of ACI-318 Code and Eurocode 2 Standard

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4938
Author(s):  
Maciej Grabski ◽  
Andrzej Ambroziak
Keyword(s):  
Parametric Analysis ◽  
Load Capacity ◽  
Selection Method ◽  
Shear Capacity ◽  
Punching Shear ◽  
Transverse Reinforcement ◽  
Shear Load ◽  
Reinforced Concrete Structure ◽  
Practical Application ◽  
Eurocode 2

The scope of the paper is to propose a method for determining the size of shear caps in a slab–column-connections-reinforced concrete structure. Usually, shear heads are used to enhance slab–column connection, especially when the transverse reinforcement does not give the required punching shear load capacity. The dimensions of the shear head should provide the punching shear resistance of the connection inside and outside the enhanced region. The process of selecting the size of the shear head is iterative. The parametric analysis of the ACI 318 code and EC2 standard has the objective of indicating which control perimeter (inside or outside the shear head) has a decisive impact on the punching shear capacity of the connection. Based on the analysis, the authors propose methods for selecting the dimensions of the shear head with practical application examples. The paper is intended to provide scientists, civil engineers, and designers with guidelines to design the process of the slab–column connections with the shear caps.

scholarly journals Model studies on plate girders

1983 ◽  
Vol 18 (2) ◽  
pp. 111-117 ◽  
Author(s):  
R Narayanan ◽  
D Adorisio
Keyword(s):  
Shear Loading ◽  
Shear Capacity ◽  
Small Scale ◽  
Structural Behaviour ◽  
Plate Girders ◽  
Model Studies ◽  
Scale Models ◽  
Shear Buckling ◽  
Post Buckling ◽  
Ultimate Shear Capacity

Tests on eighteen small scale models which simulate the elastic and post-buckling behaviour of plate girders when subjected to shear loading are reported and discussed. The models were fabricated of steel and Araldite; the major aim was to assess whether small scale models can be employed to study shear buckling problems. A secondary object was to examine whether araldite could be used for predicting the structural behaviour and ultimate loads of plate girders. The strength and post-buckling characteristics exhibited by steel models were found to be similar to those observed by earlier investigators on full scale girders. The test results of steel models have been compared with the theoretical predictions obtained by using some ten design methods developed in different countries. Most of these methods are shown to give conservative but satisfactory predictions of the ultimate shear capacity of the model steel girders. Tests on Araldite models demonstrated that post-buckling behaviour can be observed visually on account of the large elastic deformations which the material is capable of, before collapse. However, they were found to be unsuitable for the prediction of the ultimate shear capacity. As Araldite is brittle, collapse would occur prematurely by sudden fracture before the full development of the tension field.

TESTS COATINGS UNDER VARIABLE LOADS

2017 ◽  
pp. 95-98
Author(s):  
N. L. Venediktov ◽  
A. N. Venediktov ◽  
I. M. Kovenskiy
Keyword(s):  
Fatigue Testing ◽  
Laboratory Scale ◽  
Kinematic Scheme ◽  
Electrolytic Coating ◽  
Test Parameters ◽  
Experimental Laboratory

The experimental laboratory-scale plant for the fatigue testing of samples with electrolytic coating were designed and constructed. Shows the kinematic scheme and considered the principle of the plant. The dependences for determination of test parameters and the method of testing samples with coatings under variable loads were obtained.

scholarly journals A case study of university student networks and the COVID-19 pandemic using a social network analysis approach in halls of residence

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
José Alberto Benítez-Andrades ◽  
Tania Fernández-Villa ◽  
Carmen Benavides ◽  
Andrea Gayubo-Serrenes ◽  
Vicente Martín ◽  
...  
Keyword(s):  
Social Network ◽  
Social Network Analysis ◽  
Network Analysis ◽  
University Students ◽  
Methodological Approach ◽  
Centrality Measures ◽  
Structural Behaviour ◽  
Cross Sectional ◽  
Depth Analysis ◽  
The University

AbstractThe COVID-19 pandemic has meant that young university students have had to adapt their learning and have a reduced relational context. Adversity contexts build models of human behaviour based on relationships. However, there is a lack of studies that analyse the behaviour of university students based on their social structure in the context of a pandemic. This information could be useful in making decisions on how to plan collective responses to adversities. The Social Network Analysis (SNA) method has been chosen to address this structural perspective. The aim of our research is to describe the structural behaviour of students in university residences during the COVID-19 pandemic with a more in-depth analysis of student leaders. A descriptive cross-sectional study was carried out at one Spanish Public University, León, from 23th October 2020 to 20th November 2020. The participation was of 93 students, from four halls of residence. The data were collected from a database created specifically at the university to "track" contacts in the COVID-19 pandemic, SiVeUle. We applied the SNA for the analysis of the data. The leadership on the university residence was measured using centrality measures. The top leaders were analyzed using the Egonetwork and an assessment of the key players. Students with higher social reputations experience higher levels of pandemic contagion in relation to COVID-19 infection. The results were statistically significant between the centrality in the network and the results of the COVID-19 infection. The most leading students showed a high degree of Betweenness, and three students had the key player structure in the network. Networking behaviour of university students in halls of residence could be related to contagion in the COVID-19 pandemic. This could be described on the basis of aspects of similarities between students, and even leaders connecting the cohabitation sub-networks. In this context, Social Network Analysis could be considered as a methodological approach for future network studies in health emergency contexts.

A Synthesis of Aluminum Crewboat Structural Design

1982 ◽  
Vol 19 (01) ◽  
pp. 52-72
Author(s):  
William A. Henrickson ◽  
John S. Spencer
Keyword(s):  
Structural Design ◽  
Beam Theory ◽  
Coast Guard ◽  
Observation Data ◽  
Plate Girders ◽  
Worked Example ◽  
Theory Versus ◽  
Grillage Analysis ◽  
Design Stress

The need exists for a simplified structural review guide to enable U.S. Coast Guard marine inspectors to verify the structural adequacy of aluminum crewboats. The authors have developed such a guide. Typical existing crewboat forms and service speeds have been used to reduce the determination of impact pressures to a function of length and displacement. A design stress limit for the cyclic loading of the bottom structure has been determined based on wave observation data. Plating design has been verified by a comparison of sizing by beam theory versus elastoplastic analysis. A simplified grillage analysis has been used to determine the level of support provided by longitudinal plate girders or keelsons. A worked example and tables of section moduli for typical extrusions attached to plating are included as appendices.

Strengthening of a City Center Tunnel with Concrete Screw Anchors under Special Boundary Conditions

2019 ◽  
Author(s):  
Johannes Lechner ◽  
Jürgen Feix ◽  
Robert Hertle
Keyword(s):  
Ductile Failure ◽  
High Strength ◽  
Shear Capacity ◽  
City Center ◽  
Cracked Concrete ◽  
Concrete Girders ◽  
Effective Depth ◽  
The University ◽  
The City ◽  
East West

<p>The Altstadtring-Tunnel is one of the essential east-west traffic routes in the city center of Munich and was constructed in the late 1960s. Segment 34 of the tunnel was built directly underneath the existing Prince-Carl- Palais, a historic building from 1804. Therefore 15 pre-stressed concrete girders with an effective depth of</p><p>3.5 m and a maximum span of up to 30 m were built which now form the tunnel roof slab. These girders were pre-stressed with steel nowadays well known for stress corrosion cracking. A recalculation of the slab showed that no ductile failure can be guaranteed in case of a progressive rupture of the tendons. Therefore, a concept for strengthening the slab was developed using concrete screw anchors as post installed bending and shear reinforcement. The concrete screw anchors are normally installed as anchoring elements in cracked and non- cracked concrete and are available with diameters up to 22 mm. Developing this concept further, it is straight forward to use these anchoring elements as post-installed reinforcement in existing concrete structures. This new strengthening system was developed at the University of Innsbruck in the last few years and can fulfill the special requirements of this project, such as installation of the strengthening system from underneath the tunnel slab during ongoing use of the structure. High strength steel with diameters of up to 63.5 mm will be used as post-installed bending reinforcement covered with a new shotcrete layer on the underside of the tunnel slab. In total 59.3 tons of new flexural reinforcement and 7199 concrete screws for strengthening the shear capacity of the girders will be used to ensure a ductile failure of the tunnel slab. The on-site work started in March 2019 and is expected to take two years to complete.</p>

scholarly journals State space approach with FEM for the determination of structural behaviour of composite plates

2017 ◽  
Vol 8 (4) ◽  
pp. 468-483
Author(s):  
Asad Shukri Albostami ◽  
Zhangjian Wu ◽  
Zhenmin Zou
Keyword(s):  
Plate Thickness ◽  
Composite Plates ◽  
Thickness Direction ◽  
Middle Plane ◽  
Structural Behaviour ◽  
State Space Approach ◽  
Content Type ◽  
Simply Supported ◽  
Space Approach

Purpose An analytical investigation has been carried out for a simply supported rectangular plate with two different loading conditions by using 3D state space approach (SSA). Also, the accurate location of the neutral plane (N.P.) through the thickness of the plate can be identified: the N.P. is shifted away from the middle plane according to the loading condition. The paper aims to discuss these issues. Design/methodology/approach SSA and finite element method are used for the determination of structural behaviour of simply supported orthotropic composite plates under different types of loading. The numerical results from a finite element model developed in ABAQUS. Findings The effect of the plate thickness on displacements and stresses is described quantitatively. It is found that the N.P. of the plate, identified according to the values of the in-plane stresses through the thickness direction, is shifted away from the middle plane. Further investigation shows that the position of the N.P. is loading dependant. Originality/value This paper describe the effect of the plate thickness on displacements and stresses quantitatively by using an exact solution called SSA. Also, it is found that the N.P. of the plate, identified according to the values of the in-plane stresses through the thickness direction, is shifted away from the middle plane. Further investigation shows that the position of the N.P. is loading dependant.

scholarly journals Biaxial Shear Load Capacity of Anchor System for Quick-Hardening Track on Railway Bridges

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Kyoung Chan Lee ◽  
Il-Wha Lee ◽  
Seong-Cheol Lee
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
Load Capacity ◽  
Frictional Resistance ◽  
Shear Capacity ◽  
Railway Track ◽  
Railway Bridges ◽  
Anchor System ◽  
Ballast Track ◽  
Anchor Systems

Quick-hardening railway track was developed to rapidly convert old-style ballast track to slab track in order to improve its maintainability and ride comfort. On bridges, quick-hardening track is applied in a segmented structure to reduce the temperature constraint, and anchors at the centers of the segments securely couple the track to the bridge. In this study, an anchor system is proposed that facilitates fast construction, and two designs for the proposed anchor systems are provided along with experimental test results of the same. Two anchor system designs were developed to allow for the maximum possible longitudinal and transverse loads in high-speed railways while considering the frictional resistance between the track slab and bridge deck. The biaxial shear capacity of each design was investigated experimentally, and the structural capacity for biaxial shear loads was evaluated using an elliptical curve to represent the longitudinal and transverse shear capacities. The minimum friction coefficient was determined based on the results of the evaluation to minimize damage to the anchor. The results obtained from the experiments confirmed that the proposed anchor systems possess sufficient shear capacity for application on high-speed railway bridges.

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