scholarly journals Non-Destructive Tests for the Structural Assessment of a Historical Bridge over the Tua River

2013 ◽  
Vol 569-570 ◽  
pp. 390-397 ◽  
Author(s):  
Isabel Valente ◽  
Luís F. Ramos ◽  
Kevin Vasquez ◽  
Paulo Guimarães ◽  
Paulo B. Lourenço
Keyword(s):  
Failure Modes ◽  
Dynamic Testing ◽  
Numerical Models ◽  
Dynamic Properties ◽  
Dynamic Test ◽  
Truss Structures ◽  
Design Standards ◽  
Element Analysis ◽  
Modern Design ◽  
Structural Assessment

Paradela Bridge is a metallic bridge located along the bank of the Tua River in northern Portugal. While the bridge is not currently in service, its structure is representative of many metallic truss structures built across the continent between the XIX and the XX century. Tua Line belongs to the Douro area that UNESCO recently declared as world heritage. This study acquires its importance since it might serve as an insight for the study of many other similar structures all over the country. This paper comprises a historic investigation of archived documents, an on-site survey to evaluate its present conditions, a dynamic testing and the construction and calibration of numerical models in finite element analysis (FEA) software, structural assessment and capacity rating estimation. The purpose of constructing numerical models was to evaluate the suitability of the bridge under the original loading and in accordance to modern design standards. The historical research revealed that the truss bridge was designed as a simply supported element and that a series of hand calculations were carried out on individual structural elements (e.g. main trusses, stringers and floor beams). Furthermore, a dynamic test was conducted in order to identify the global dynamic properties of the structure and to calibrate numerical models that ensure reliability and representativeness. FE models served through the structural assessment of the bridge in accordance with modern design codes and to estimate the safety of the bridge. Likewise, a nonlinear failure analysis was also conducted in order to estimate the capacity rate of the bridge and the likely failure modes.

scholarly journals Numerical Behaviour of Composite K-Joints Subjected to Combined Loading and Corrosive Environment

2018 ◽  
Author(s):  
Chao Hou ◽  
Shameer Saleh ◽  
Lin-Hai Han ◽  
You-Xing Hua
Keyword(s):  
Failure Modes ◽  
Full Range ◽  
Steel Tube ◽  
Combined Loading ◽  
Truss Structures ◽  
Mechanism Analysis ◽  
Corrosive Environment ◽  
Range Analysis ◽  
Element Analysis ◽  
Fea Model

Concrete filled steel tubular (CFST) truss structures have been adopted in various infrastructures worldwide for past several decades. Application of CFST truss is more prevalent especially in areas where harsh marine condition with chloride corrosion limits the design life of structures. Design of joints is one of the most complicated issues in CFST truss structures; and it becomes more critical when corrosion causes section loss in the outer steel tube. Improved designs in terms of economy and durability need to be suggested based on rational research on composite K-joints in corrosive environment, whilst such research is very limited up until now. This paper thus attempts to study the behaviour of circular concrete filled steel tubular (CFST) K-joints under combined effect of long-term loading and corrosion. A finite element analysis (FEA) model is presented and verified against existing test results. The model is then utilized to perform mechanism analysis of CFST K-joints under varying loading and corrosion situations. Failure modes, detailed propagation of yield and stress distribution between the core concrete in chord and the tubular steel is investigated, based on which a favourable mode of failure is suggested in terms of maximum joint capacity. Finally, a full range analysis of the load-deformation characteristics is carried out for various corrosion situations, with the corresponding joint strength as well as ductility predicted.

scholarly journals Experimental and Numerical Investigation into Failure Modes of Tension Angle Members Connected by One Leg

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5141
Author(s):  
Edyta Bernatowska ◽  
Lucjan Ślęczka
Keyword(s):  
Numerical Simulations ◽  
Failure Mode ◽  
Failure Modes ◽  
Experimental Testing ◽  
Load Capacity ◽  
Strength Function ◽  
Experimental Tests ◽  
Material Model ◽  
Design Standards ◽  
Element Analysis

This paper presents the results of experimental and numerical tests on angle members connected by one leg with a single row of bolts. This study was designed to determine which failure mode governs the resistance of such joints: net section rupture or block tearing rupture. Experimental tests were insufficient to completely identify the failure modes, and it was necessary to conduct numerical simulations. Finite element analysis of steel element resistance based on rupture required advanced material modelling, taking into account ductile initiation and propagation of fractures. This was realised using the Gurson–Tvergaard–Needleman porous material model, which allows for analysis of the joint across the full scope of its behaviour, from unloaded state to failure. Through experimental testing and numerical simulations, both failure mechanisms (net section and block tearing) were examined, and an approach to identify the failure mode was proposed. The obtained results provided experimental and numerical evidence to validate the strength function used in design standards. Finally, the obtained results of the load capacity were compared with the design procedures given in the Eurocode 3′s current and 2021 proposed editions.

Parametric Study of Static Strength of Multiplanar KK-Joints：Square Chords and Circular Braces

2011 ◽  
Vol 250-253 ◽  
pp. 1527-1532
Author(s):  
Ai Guo Chen ◽  
Wei Liang Huang ◽  
Rui Zeng Shan ◽  
Qing Shan Yang
Keyword(s):  
Parametric Study ◽  
Large Scale ◽  
Failure Modes ◽  
Numerical Models ◽  
Axial Loading ◽  
Steel Structure ◽  
Geometric Parameters ◽  
Truss Structures ◽  
Hollow Section ◽  
Circular Hollow Section

Pre-stressed spatial tubular truss system is adopted in steel roof truss structures of China International Exhibition Center New Venue. Bottom chord joints are multiplanar KK-joints consisting of chord with square hollow section and brace with circular hollow section. However, not only that relatively little research has been carried out on such joints, but also that no detailed design guidance on KK-type joints consisting of chord with square hollow section and brace with circular hollow section can be found Current design code for steel structure (GB 50017-2003). This paper reports the study into the strength of this type of KK-joints under axial loading. The numerical models were adopted, and several various geometric parameters which affect the strength and failure modes, were investigated. It was indicated that the geometric parameters affects significantly the ultimate capacity and failure modes of the joints. The varied relationship of the strength and failure mode with parameter varying was studied in detail. The results of the work presented provide initial discussion on behavior of this type of KK-joints and lay the foundation for a future large-scale parametric study and put out design formula.

Dynamic Testing under Nonsinusoidal Conditions and the Consequences of Nonlinearity for Service Performance

1987 ◽  
Vol 60 (5) ◽  
pp. 870-887 ◽  
Author(s):  
J. A. Harris
Keyword(s):  
Harmonic Analysis ◽  
Dynamic Behavior ◽  
Dynamic Testing ◽  
Dynamic Properties ◽  
Dynamic Test ◽  
Time History ◽  
Test System ◽  
Service Environment ◽  
Harmonic Components ◽  
Vibration Tests

Abstract In this work, nonlinearity in the dynamic behavior of rubber has been considered. In order to understand its effects in a service environment involving complex patterns of vibration, it has been necessary to clarify the derivations of dynamic properties for the sinusoidal excitation that is conventionally used in testing. Using the fundamental frequency components as a basis, non-linearity can be quantified by the harmonic components that it produces. A dynamic test system has been developed which incorporates the ability to perform a harmonic analysis, and the usefulness of this has been demonstrated. Harmonic analysis has enabled the dynamic behavior of rubber to be quantified under complex, periodic waveforms. This is necessary for filled rubbers, because their nonlinearity means that a superposition on their properties from sinusoidal tests is incorrect. Examples of this approach for assessing dynamic behavior range from shock mounts to tire treads. Dual-sine tests on a nonlinear rubber indicate that for complex vibrations, consisting of many amplitudes and frequencies, the overall dynamic behavior will tend toward that obtained in single sine tests at a strain amplitude which corresponds to the largest amplitude that occurs in the time history. A similar conclusion is drawn from random vibration tests with a continuous spectrum of vibrations. The result of this is that under a more complex system of vibrations, nonlinear rubbers will behave in a more linear fashion and will exhibit higher damping than indicated by their dynamic properties measured in conventional sinusoidal tests. Therefore, when the service environment of many components is taken into account, the dynamic behavior of nonlinear rubbers may give better performance characteristics than expected from conventional testing.

scholarly journals Forensic Engineering Analysis of Failed UTV Roll Cages

2016 ◽  
Vol 33 (1) ◽  
Author(s):  
Olof Jacobson ◽  
Stephen A. Batzer ◽  
Mark Kittel ◽  
Jesse A. Grantham ◽  
Guy J. Barbera ◽  
...  
Keyword(s):  
Failure Modes ◽  
Dynamic Testing ◽  
Engineering Analysis ◽  
Cage Structure ◽  
Element Analysis ◽  
Design Concepts ◽  
Dirt Road ◽  
Analysis Laboratory ◽  
Forensic Engineering ◽  
Alternative Designs

Two cases were analyzed that involved pitchover/rollover accidents of the same model side by side utility terrain vehicle (UTV). In each case, the UTV ran over a bump on a dirt road and pitched over. The roll cages collapsed, and the drivers suffered significant injuries. Both roll cages collapsed in a similar manner. The design and failure modes of the roll cage structure were analyzed. Engineering analysis included dynamic analysis, laboratory testing, vehicle dynamic testing, finite element analysis, and a review of fundamental mechanical engineering design concepts. Roll cage design and applicable standards were evaluated. Reasonable alternative designs were identified and analyzed.

scholarly journals Dynamic Test of a Viaduct on the Orastie–Sibiu Highway

2017 ◽  
Vol 6 (1) ◽  
pp. 15-29 ◽  
Author(s):  
Ghindea Cristian Lucian ◽  
Răcănel Ionuţ Radu ◽  
Cruciat Radu Iuliu
Keyword(s):  
Dynamic Testing ◽  
Numerical Models ◽  
Damping Ratio ◽  
Dynamic Test ◽  
Time History ◽  
Element Model ◽  
Dynamic Impact ◽  
Bridge Superstructure ◽  
Special Solutions ◽  
Dynamic Impact Factor

Abstract Dynamic testing of bridges has as target to establish their response on pulse forces between the wheels and unevenness of road surface. Generally, during the tests, real time accelerations or deformations are to be measured and which through successive processing methods lead to other data as velocities, displacements, dynamic impact factor, but also the damping ratio. In order to validate the bridge response following testing, the measured data are compared both with allowable limits existing in standards and with the results obtained using analytical or numerical models. In Romania, the dynamic testing of bridges is recommended by the current standards, only for important bridges, erected in complex or special solutions and also for large span bridges. The aim of this paper is to outline the results obtained from the on-site measurements during dynamic testing of a viaduct placed on the motorway A1, sector Orăştie-Sibiu. The bridge superstructure is a composite one, continuous girder on 12 spans: 40+10×60+40 m, the substructure consisting in 11 piers with lamellar elevations and variable height in the range 8.50-24m. In the paper a finite element model is also presented which was used for time-history analyses using an impulse type load. Finally, the results obtained on the site and using the numerical model are compared and discussed.

Cold-formed steel battened built-up columns: Experimental behaviour and verification of different design rules developed

2021 ◽  
pp. 136943322110480
Author(s):  
A.R. Dar ◽  
S. Vijayanand ◽  
M. Anbarasu ◽  
M. Adil Dar
Keyword(s):  
Failure Modes ◽  
Numerical Models ◽  
Experimental Studies ◽  
Design Standards ◽  
Uniform Compression ◽  
Design Rules ◽  
The North ◽  
Current Design ◽  
Cold Formed Steel ◽  
In The Beginning

Some of the past studies on cold-formed steel (CFS) battened built-up columns have resulted in the development of new design rules for predicting their axial strengths. However, the main drawbacks of such studies are that they are purely numerical and the numerical models developed for such parametric studies were validated using the test results on similar built-up column configurations, but not the exact ones. Therefore, experimental studies on CFS battened columns comprising of lipped channels are needed for verifying the accuracy of the proposed design rules for CFS battened columns. This paper reports an experimental study performed on CFS built-up battened columns under axial compression. Adequately spaced identical lipped channels in the back-to-back arrangement were used as chords and were connected by batten plates laterally with self-driving screws to form the built-up members. The dimensions of chords were fixed as per the geometric limits given out in the North American Specifications (NAS) for the design of CFS structural members. The sectional compactness of the chords and the overall slenderness of the built-up columns were varied by altering the thickness of the channels and height of the built-up columns, respectively. A total of 20 built-up sections were tested under uniform compression to investigate the behavioural changes in the built-up columns due to these variations. The behaviour assessment was made in terms of peak strengths, load–displacement response and failure modes of the test specimens. The current design standards on CFS structures were used to determine the design strengths and were compared against the test strengths for assessing their adequacy. Furthermore, as discussed in the beginning, the test strengths were used to verify the accuracy of the different relevant proposed design rules in the literature.

Section bending resistance of new Hybrid Double-I-Box Beams

2018 ◽  
Vol 21 (11) ◽  
pp. 1676-1695 ◽  
Author(s):  
MS Deepak ◽  
VM Shanthi
Keyword(s):  
Numerical Models ◽  
Torsional Rigidity ◽  
Local Buckling ◽  
Steel Structures ◽  
Test Results ◽  
Design Standards ◽  
Element Analysis ◽  
Box Beam ◽  
Bending Resistance ◽  
Moment Of Resistance

This article contains original works of testing and numerical validation on section bending resistance of new innovative built-up thin-walled metal Hybrid Double-I-Box Beam sections when subjected to local buckling. The cross section of Hybrid Double-I-Box Beam section is distinctive, which has advantages of both an ‘I’ section and a closed-box section. A total of 24 sections in three series that includes 8 homogeneous sections and 16 hybrid sections were tested under four-point bending. The varying parameters considered in the test specimens were as follows: first, hybrid parameter ratio, that is, yield strengths of flange steel to web steel (Φh = fyf/fyw); second, the ratio of breadth to the overall depth (B/D) of the section; and third, the flange thickness (tf). The moment-resisting capacity of these built-up sections are high due to the presence of more material at the flanges. The closed box-web portion provides higher torsional rigidity. From the test results, it was found that the hybrid sections have higher bending resistance capacity than the homogeneous sections, so technically gains more strength to weight. The increase in B/D ratio gained the increase in both major and minor axis bending resistance. The intermediate flange stiffener which alters the flange plate slenderness (λpf) had a significant effect on the local buckling resistance of the flange plate. Verification of numerical models followed by a parametric study was undertaken using ABAQUS finite element analysis software. The test results obtained were compared with the predicted design moment of resistance (Mc,Rd) as per Eurocode design standards EN 1993-1-3: 2006-Design of Steel Structures for Cold-Formed Steel Members and Sheeting and the adequacy is confirmed.

Load Testing to Collapse Limit State of Barr Creek Bridge

2000 ◽  
Vol 1696 (1) ◽  
pp. 92-102 ◽  
Author(s):  
Nicholas Haritos ◽  
Anil Hira ◽  
Priyan Mendis ◽  
Rob Heywood ◽  
Armando Giufre
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Flexural Rigidity ◽  
Load Capacity ◽  
Limit State ◽  
Dynamic Test ◽  
Service Condition ◽  
Flat Slab ◽  
Testing Program ◽  
Static Testing

VicRoads, the road authority for the state of Victoria, Australia, has been undertaking extensive research into the load capacity and performance of cast-in-place reinforced concrete flat slab bridges. One of the key objectives of this research is the development of analytical tools that can be used to better determine the performance of these bridges under loadings to the elastic limit and subsequently to failure. The 59-year-old Barr Creek Bridge, a flat slab bridge of four short continuous spans over column piers, was made available to VicRoads in aid of this research. The static testing program executed on this bridge was therefore aimed at providing a comprehensive set of measurements of its response to serviceability level loadings and beyond. This test program was preceded by the performance of a dynamic test (a simplified experimental modal analysis using vehicular excitation) to establish basic structural properties of the bridge (effective flexural rigidity, EI) and the influence of the abutment supports from identification of its dynamic modal characteristics. The dynamic test results enabled a reliably tuned finite element model of the bridge in its in-service condition to be produced for use in conjunction with the static testing program. The results of the static testing program compared well with finite element modeling predictions in both the elastic range (serviceability loadings) and the nonlinear range (load levels taken to incipient collapse). Observed collapse failure modes and corresponding collapse load levels were also found to be predicted well using yield line theory.

scholarly journals The research of dynamic impacts on the hydraulic structure foundation base, transformed in the process of accident recovery

2018 ◽  
Vol 251 ◽  
pp. 04040
Author(s):  
Zaven Ter-Martirosyan ◽  
Ivan Luzin
Keyword(s):  
Field Experiments ◽  
Dynamic Properties ◽  
Soil Parameters ◽  
Experimental Site ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Foundation Base ◽  
Dynamic Impacts ◽  
Scale Experiment ◽  
Selection Of

The article presents the results of a comprehensive research of the dynamic impacts on a modified base. The modified base was obtained as a result of compensatory injection at the experimental site for the accident recovery at the hydraulic engineering structure. The complex study of the dynamic impacts includes special laboratory tests to determine the soil parameters, the finite element analysis of the experimental site, taking into account the dynamic properties, the selection of the necessary equipment for field experiments based on the numerical solution results, a full-scale experiment with the measurement of the foundation sediments of the experimental site.

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