Temperature Action Monitoring of Main Girder

2018 ◽  
pp. 3-26
Author(s):  
Yang Deng ◽  
Aiqun Li
Keyword(s):  
Action Monitoring ◽  
Temperature Action ◽  
Main Girder

The Metaphorical Mapping of Social Affection on Temperature: Action Mechanisms and Its Explanation

2013 ◽  
Vol 21 (6) ◽  
pp. 1133-1140
Author(s):  
Yi DING ◽  
Tingting JI ◽  
Wenqian ZOU ◽  
Yan LIU ◽  
Guangming RAN ◽  
...  
Keyword(s):  
Action Mechanisms ◽  
Metaphorical Mapping ◽  
Temperature Action

The Influence of Slab Concreting Sequence on a Continuous Composite Girder Bridge

2016 ◽  
Vol 691 ◽  
pp. 96-107
Author(s):  
Tomas J. Zivner ◽  
Rudolf B. Aroch ◽  
Michal M. Fabry
Keyword(s):  
Concrete Slab ◽  
Transverse Cross Section ◽  
Slab Thickness ◽  
Slab Width ◽  
Composite Girder ◽  
Steel Members ◽  
Composite Bridge ◽  
Bridge Girder ◽  
Girder Bridge ◽  
Main Girder

This paper deals with the slab concreting sequence and its influence on a composite steel and concrete continuous highway girder bridge. The bridge has a symmetrical composite two-girder structure with three spans of 60 m, 80 m, 60 m (i.e. a total length between abutments of 200.0 m). The horizontal alignment is straight. The top face of the deck is flat. The bridge is straight. The transverse cross-section of the slab is symmetrical with respect to the axis of the bridge. The total slab width is 12 m. The slab thickness varies from 0.4 m on main girders to 0.25 m at its free edges and 0.3075 m at its axis of symmetry. The center-to-center spacing between main girders is 7 m and the slab cantilever on either side is 2.5 m long. Every main girder has a constant depth of 2800 mm and the thicknesses of the upper and lower flanges are variable. The lower flange is 1200 mm wide whereas the upper flange is 1000 mm wide. The two main girders have transverse bracing at abutments and at internal supports and at regular intervals in every span. The material of concrete slab is C35/45 and of steel members S355. The on-site pouring of the concrete slab segments is performed by casting them in a selected order and is done after the launching of the steel two girder bridge. The paper presents several concreting sequences and their influence on the normal stresses and deflections of the composite bridge girder.

scholarly journals Analysis of Vehicle Collision on an Assembled Anti-Collision Guardrail

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5152
Author(s):  
Juncheng Yao ◽  
Bo Wang ◽  
Yujie Hou ◽  
Liang Huang
Keyword(s):  
Working Conditions ◽  
Traffic Accidents ◽  
Analysis Software ◽  
Time Curve ◽  
Vehicle Collisions ◽  
Moving Vehicle ◽  
Vehicle Collision ◽  
New Type ◽  
Main Girder ◽  
Protective Performance

Traffic accidents such as vehicle collisions with bridge guardrails occur frequently. These accidents cause damage to the driver and the vehicle as well as the bridge. A new type of assembled anti-collision guardrail is proposed in this study. LS-DYNA is a nonlinear display dynamic analysis software used to evaluate the safety of a new type of assembled anti-collision guardrail. A specific, numerically analyzed model of vehicle–guardrail collision is established using LS-DYNA. The energy distribution–time curve of the vehicle collision process is obtained. After comparison with measured data from the vehicle collision test, the model of vehicle–guardrail collision is verified as being correct. Based on this, we analyze the process of a vehicle collision on the assembled anti-collision guardrail. The result shows that the assembled anti-collision guardrail proposed in this paper can better change the trajectory of a moving vehicle and can prevent the vehicle from falling off the bridge. From the car body collision results, the assembled anti-collision guardrail for bridges proposed in this paper can reduce vehicle damage and can protect the driver effectively. From the analysis of the main girder stress on the bridge, an anti-collision guardrail installed on an existing bridge will not cause damage to the main girder during a collision. In order to study the influence of the four parameters on the anti-collision effect, we carried out a comparative calculation of multiple working conditions. The results show that the new type of assembled anti-collision guardrail has good protective performance under different working conditions.

scholarly journals Altered sense of agency in Gilles de la Tourette syndrome: behavioural, clinical and functional magnetic resonance imaging findings

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Laura Zapparoli ◽  
Silvia Seghezzi ◽  
Francantonio Devoto ◽  
Marika Mariano ◽  
Giuseppe Banfi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Tourette Syndrome ◽  
Sense Of Agency ◽  
Healthy Controls ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Intentional Binding ◽  
Action Monitoring

Abstract Current neurocognitive models of motor control postulate that accurate action monitoring is crucial for a normal experience of agency—the ability to attribute the authorship of our actions and their consequences to ourselves. Recent studies demonstrated that action monitoring is impaired in Gilles de la Tourette syndrome, a movement disorder characterized by motor and vocal tics. It follows that Tourette syndrome patients may suffer from a perturbed sense of agency, the hypothesis tested in this study. To this end, we recruited 25 Tourette syndrome patients and 25 matched healthy controls in a case-control behavioural and functional magnetic resonance imaging study. As an implicit index of the sense of agency, we measured the intentional binding phenomenon, i.e., the perceived temporal compression between voluntary movements and their external consequences. We found evidence of an impaired sense of agency in Tourette syndrome patients who, as a group, did not show a significant intentional binding. The more reduced was the individual intentional binding, the more severe were the motor symptoms. Specific differences between the two groups were also observed in terms of brain activation patterns. In the healthy controls group, the magnitude of the intentional binding was associated with the activity of a premotor–parietal–cerebellar network. This relationship was not present in the Tourette syndrome group, suggesting an altered activation of the agency brain network for self-generated acts. We conclude that the less accurate action monitoring described in Tourette syndrome also involves the assessment of the consequences of actions in the outside world. We discuss that this may lead to difficulties in distinguishing external consequences produced by their own actions from the ones caused by others in Tourette syndrome patients.

scholarly journals Experimental investigation on composite beams under combined negative bending and torsional moments

2020 ◽  
pp. 136943322098166
Author(s):  
Weiwei Lin
Keyword(s):  
Ultimate Load ◽  
Mechanical Performance ◽  
Composite Beams ◽  
Strain Development ◽  
Shear Connectors ◽  
Load Carrying ◽  
Interface Slip ◽  
Negative Bending ◽  
Support Conditions ◽  
Main Girder

In this study, straight composite steel-concrete beams were tested to investigate their mechanical performance under combined negative bending and torsional moments. Two specimens were used in this study, and different ratios between the applied negative bending and torsional moments were induced. Load and deflection relationships, strain development on the steel main girder and shear connectors (stud), and the slip development on the steel-concrete interface were recorded in the test and reported in this paper. The results indicate that increase of torsional moment will result in the significant decrease of the load-carrying capacities (e.g. yield load and ultimate load) of the specimens. It was also found that the normal strains of stud shear connectors in such beams are very large and non-negligible compared to their shear strains. In addition, the maximum interface slip was found occurring at around the 1/4 span, and the support conditions and serious crack of the concrete were considered to be the main causes. The research results obtained in this study can provide references for the design and analysis of steel-concrete composite beams subjected to the combined negative bending and torsional moments.

scholarly journals Transient Response of Bridge Piers to Structure Separation under Near-Fault Vertical Earthquake

2021 ◽  
Vol 11 (9) ◽  
pp. 4068
Author(s):  
Wenjun An ◽  
Guquan Song
Keyword(s):  
Large Scale ◽  
Bending Moment ◽  
Relative Displacement ◽  
Superposition Method ◽  
Longitudinal Displacement ◽  
Transient Wave ◽  
Vibration Period ◽  
Vertical Excitation ◽  
Mode Superposition Method ◽  
Main Girder

Given the possible separation problem caused by the double-span continuous beam bridge under the action of the vertical earthquake, considering the wave effect, the transient wave characteristic function method and the indirect mode superposition method are used to solve the response theory of the bridge structure during the earthquake. Through the example analysis, the pier bending moment changes under different vertical excitation periods and excitation amplitudes are calculated. Calculations prove that: (1) When the seismic excitation period is close to the vertical natural vibration period of the bridge, the main girder and the bridge pier may be separated; (2) When the pier has a high height, the separation has a more significant impact on the longitudinal displacement of the bridge, but the maximum relative displacement caused by the separation is random; (3) Large-scale vertical excitation will increase the number of partitions of the structure, and at the same time increase the vertical collision force between the main girder and the pier, but the effect on the longitudinal displacement of the form is uncertain; (4) When V/H exceeds a specific value, the pier will not only be damaged by bending, but will also be damaged by axial compression.

scholarly journals Mathematical Modeling for Lateral Displacement Induced by Wind Velocity Using Monitoring Data Obtained from Main Girder of Sutong Cable-Stayed Bridge

2014 ◽  
Vol 2014 ◽  
pp. 1-16
Author(s):  
Gao-Xin Wang ◽  
You-Liang Ding
Keyword(s):  
Time Series ◽  
Wind Velocity ◽  
Lateral Displacement ◽  
Third Order ◽  
Nonlinear Correlation ◽  
Cable Stayed Bridge ◽  
Spectrum Density ◽  
Combined Models ◽  
Main Girder ◽  
Correlation Term

Based on the health monitoring system installed on the main span of Sutong Cable-Stayed Bridge, GPS displacement and wind field are real-time monitored and analyzed. According to analytical results, apparent nonlinear correlation with certain discreteness exists between lateral static girder displacement and lateral static wind velocity; thus time series of lateral static girder displacement are decomposed into nonlinear correlation term and discreteness term, nonlinear correlation term of which is mathematically modeled by third-order Fourier series with intervention of lateral static wind velocity and discreteness term of which is mathematically modeled by the combined models of ARMA(7,4)and EGARCH(2,1). Additionally, stable power spectrum density exists in time series of lateral dynamic girder displacement, which can be well described by the fourth-order Gaussian series; thus time series of lateral dynamic girder displacement are mathematically modeled by harmonic superposition function. By comparison and verification between simulative and monitoring lateral girder displacements from September 1 to September 3, the presented mathematical models are effective to simulate time series of lateral girder displacement from main girder of Sutong Cable-Stayed Bridge.

Investigation on endurance evaluation of a portal crane: experimental, theoretical and finite element analysis

2020 ◽  
Vol 62 (4) ◽  
pp. 357-364
Author(s):  
Yusuf Aytaç Onur ◽  
Hakan Gelen
Keyword(s):  
Finite Element ◽  
Critical Points ◽  
Maximum Stress ◽  
Strain Gages ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Element Simulation ◽  
Main Girder ◽  
Stressed Component ◽  
Portal Crane

Abstract In this study, the stress on portal crane components at various payloads has been investigated theoretically, numerically and experimentally. The portal crane was computer-aided modeled and finite element analyses were performed so that the most stressed points at the each trolley position investigated on the main girder could be determined. In addition, the critical points were marked on the portal crane, and strain gages were attached to the those critical points so that stress values could be experimentally determined. The safety factor values at different payloads were determined by using finite element simulation. Results indicate that the most stressed component in the examined portal crane is the main girder. Experimental results indicate that the maximum stress value on the main girder is 3.05 times greater than the support legs and 8.99 times larger than the rail.

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