Performance Of Deck Research Articles

Flexural performance and crack width prediction of steel-UHTCC composite bridge decks with wet joints

Composite bridge deck (CBD) structure has been widely used in recent decades, particularly in long-span bridges. The application of ultra-high toughness cementitious composite (UHTCC) in composite bridge deck (CBD) structures has garnered attention due to its exceptional resistance to tensile cracking and strain hardening. However, their widespread adoption necessitates a thorough understanding of crack resistance, especially in the presence of wet joints between cast regions. This study investigates the flexural performance and crack width prediction method of steel-UHTCC/concrete CBDs with wet joints using a combined experimental and theoretical approach. Six specimens with UHTCC wet joints and either UHTCC or concrete precast layers were designed and tested under hogging moment. The analysis focused on failure modes, load-deflection responses, and crack development while considering the wet joints. All specimens exhibited interfacial slip between the UHTCC/concrete layer and the steel beam. A novel theoretical model was developed to predict crack width in steel-UHTCC/concrete CBDs with wet joints. This model incorporates established crack theories for fiber-reinforced concrete while explicitly accounting for the strain-hardening behavior of UHTCC. Furthermore, this model provides a detailed bending analysis of steel-UHTCC CBDs considering the interface slip phenomenon, to derive various mechanical parameters for crack width prediction.

Aerodynamic and flutter performance of the bridge deck with various countermeasures using computational fluid dynamics

Aerodynamic layouts of bridge decks considerably affect aerostatic torsional divergence and flutter for bridges. The crucial operation is choosing the optimal bridge deck shape considering the aerodynamic effect. The present study intends to provide a better solution for the flutter control scheme by changing five aspect ratios and four passive aerodynamic countermeasures. The countermeasures are an eccentric wing, inspection rail, down vertical central stabilizer and wind barrier, which have been used for three deck shapes: streamlined, semi-streamline and bluff body sections with large angles of attack. Nowadays, wind barriers are frequently installed on bridges to shield vehicles from the harmful effects of crosswinds, which can influence the flutter characteristics of the bridge. Therefore, the present study contemplates reducing the flutter effect with countermeasures. These countermeasures adversely affect the deck’s dynamic stability, mainly manifested in the different divergence forms of the structure. Finally, the eccentric wing, which runs parallel to the bridge deck, increases the critical flutter speed. However, the flow that passes through the eccentric wing extracts considerable energy from the flow field of the countermeasure. Therefore, the framework and solution of the present investigation are sustainable and safe for bridge design.

Numerical investigation on structural performance of GFRP composite bridge decks

Numerical investigation on structural performance of GFRP composite bridge decks

Numerical and Theoretical Study on Flexural Performance and Reasonable Structural Parameters of New Steel Grating–UHPFRC Composite Bridge Deck in Negative Moment Zone

As the bridge’s structural component is directly subjected to vehicle loads, the stress performance of the bridge deck has a significant impact on the safety, durability, and driving comfort of the bridge. In order to improve the bending performance of the bridge deck in the negative moment zone, a new type of steel grating–UHPFRC composite bridge deck was proposed in this paper. Firstly, structural details and advantages of the new steel grating-UHPFRC composite bridge deck were introduced. Secondly, the finite element program ABAQUS was used to establish a refined solid finite element model of the new bridge deck. The mathematical program MATLAB (PYTHON) was also used to analyze the effects of the structural parameters on bending bearing capacity and put forward reasonable structural parameters of the new bridge deck, considering the technical and economic indexes. Thirdly, the simplified plasticity theory was applied to analyze the bending bearing capacity of the new bridge deck, and the corresponding formula for bending bearing capacity calculation was derived and verified by numerical model results. In addition, the cost–benefit analysis and environmental impact assessment of the new bridge deck were also conducted. The results show that the bending bearing capacity of the new bridge deck in the negative moment zone increases with the increase of the width of the bridge deck, the thickness of the wing plate, and the height of the web plate, with a trend of increasing and then decreasing when the horizontal inclination of the web plate decreases. The bridge deck width does not have a significant effect on improving the bearing capacity. The bearing capacity calculated by theoretical formulas is close to that calculated by numerical models and the maximum relative deviation is 9.1%. The new steel grating-UHPFRC composite bridge deck proposed in this paper is superior to conventional steel-UHPC composite bridge deck in terms of cost-benefit and environmental impact.

Numerical Evaluation of the performance of different composite bridge decks.

Abstract A comparative analysis was conducted to facilitate the selection of composite bridge deck configurations. Composite bridge decks, with their lightweight design, corrosion resistance, prefabrication, reduced construction time, and wide design flexibility, reduce substructure costs and offer durability. Static and buckling analyses were conducted using finite element software to compare their weight, stiffness, composite inverse reverse factor, and buckling resistance. The analyses considered the same boundary conditions, loads, composite layup configuration, and material mechanical properties. Various geometries were selected from different literature to evaluate their performance and identify an appropriate design. This paper presents a numerical investigation into the structural performance of five different composite bridge decks under the same conditions. G. Rectangle emerged as the easiest manufacturing deck, consisting of pultruded rectangle tubes, and the worst deck for deflection and buckling. The G. Triangle has the lowest deflection and the highest strain energy density. The G. Arch distinguished as the lightest bridge deck, also has good performance against buckling and a low strain energy density. Finally, the G. 2Trapezoidal and G. Trapezoidal have better total performance than all other decks as they have the highest inertia.

Fatigue performance of innovative open-rib orthotropic steel deck for super-long suspension bridge

This paper presents experimental and numerical studies on the fatigue performance of an innovative orthotropic steel deck (OSD) with open-ribs, apple-shaped cut-outs, and additional transverse ribs, which is employed by the Zhangjinggao Yangtze River Bridge. This bridge is set to become the world's longest suspension bridge upon completion. A full-scale section of the OSD was fabricated and subjected to fatigue loading with a total cycle of 12.3 million times. The interested cracking-prone fatigue details include rib-to-deck and rib-to-crossbeam welded joints, along with the apple-shaped cut-outs of the crossbeam. Experimental results indicated that fatigue cracks initiated separately beneath the deck plate, on the flange of the rib, and at the rib-to-crossbeam welded joint, with equivalent stress amplitudes of 159 MPa, 148 MPa, and 99 MPa at 2 million cycles, respectively. In addition, detailed finite element model of the OSD was developed using ABAQUS and validated against the experimental results. The effects of the geometry dimensions and structural details of the bridge deck, longitudinal ribs, crossbeams and transverse ribs that influence the fatigue performance of this OSD were analyzed and discussed. Parametric analyses revealed that increasing the thickness of the deck plate, the thickness or the height of the longitudinal rib, and the number of transverse ribs can effectively reduce the stress amplitudes at corresponding fatigue details, which therefore improves their fatigue performance. This study provides useful references for the fatigue evaluation and design of OSDs with open-ribs and apple-shaped cut-outs.

Mechanical behavior improving study of concrete deck of main beam at pylon root of composite beam cable-stayed bridge

Steel-concrete composite beam has been increasingly applied to large span cable-stayed bridges. It takes full advantage of the material properties of steel and concrete. However, the concrete deck bears tension in the negative moment zone, such as zero block, which is disadvantageous to structures. Aiming at this problem, a finite element model of the zero block in the negative moment zone of a semi-floating cable-stayed bridge is built, and the local mechanical performance of the bridge deck under completed status is studied. Based on the analysis results, three improvement measures have been proposed. The improvement effect of each method and composed of three methods has been studied. The numerical results show that the whole zero block zone is in the compressed state under the combined action of the bending moment and axial force of the stay cable. However, the local negative moment effect in the zero block zone is very prominent under the support of the diaphragm plate. Removing parts of the diaphragm plate at the bearing position can significantly improve local mechanical behavior in the concrete deck, which transfers the local support to the adjacent two diaphragm plates. The composed improvement effect is prominent when the three measures are adopted simultaneously.

Flexural behaviour of the segmental precast concrete decks post-tensioned by GFRP rods

This paper introduces an innovative post-tensioned segmental concrete deck system internally reinforced and tied with GFRP reinforcements for application in pontoon decks and other deck structures in aggressive marine environments. Utilisation of the GFRP reinforcements in floating concrete structures is essential because of their non-corrosive characteristics. Six large-scale segmental decks following the specifications of Queensland maritime infrastructure were designed, manufactured, and tested to assess the reliability of the new construction system under static flexural loading in the flatwise and edgewise orientations. One segmental deck served as a reference with hand-tight post-tensioning, while the remaining specimens were connected by the GFRP rods with varying levels of post-tensioning. All decks were tested up to failure, allowing for an investigation of their flexural strength, load-strain behaviour, joint opening, and failure mechanism. The results showed that post-tensioning the GFRP rods improves the flexural performance of the segmental decks. The higher the level of post-tensioning, the higher the contact area between the segments at the joint is achieved. A numerical model was developed to understand the detailed mechanism of both flatwise and edgewise specimens. A strain reduction coefficient in the segmental concrete deck under flexure is introduced accounting for the joint presence to reliably calculate the stress in the post-tensioned internal GFRP rod when the concrete in the joint crushes. The system investigated can increase maritime and recreational infrastructure's construction efficiency and provide creative solutions in the GFRP-reinforced concrete structures in the building and construction industry.

Bending performance of prefabricated ultra-thin UHPC unit plate reinforced orthotropic steel bridge decks

To address the challenges related to lengthy construction period, complex maintenance requirement, and the elevated risk of shrinkage cracking associated with cast-in-place UHPC reinforcement of orthotropic steel bridge decks. This paper proposes a novel solution that prefabricated ultra-high-performance concrete (UHPC) slab with epoxy bond connection is used as a reinforcement layer for orthotropic steel bridge decks. Four sets of bending tests on composite bridge deck were carried out to compare the flexural performance of composite bridge decks under different joint forms and loading patterns. The results indicate that the precast UHPC decks delaminated from the epoxy bonding layer without failure of the epoxy layer itself in all cases. The positive bending capacity of the jointless composite bridge deck is approximately 27.67 kN, while the negative bending capacity is around 16.58 kN. For the composite bridge deckwith epoxy adhesive joints (EA-J-Ln), the negative bending capacity is 2.54 kN, and the negative bending capacity of the joint area reinforced with carbon fiber cloth (EA-JC-Ln) is increased to 4.17 kN. Therefore, the use of carbon fiber cloth can significantly improve the bending resistance of the joints. Finally, numerical model of the composite deck based on Cohesive Zone Model (CZM) was established, validating the applicability of this simulation method in the novel composite bridge deck.

Performance of recycled aggregate concrete composite metal decks under elevated temperatures: a comprehensive review

ABSTRACT This comprehensive review explores the performance of composite metal decks and structural elements incorporating recycled aggregate concrete (RAC) at elevated temperatures. Despite the acknowledged environmental benefits of using recycled aggregates in concrete production, there is a notable gap in the literature regarding their behaviour under fire conditions. The investigation delves into studies encompassing fire resistance, physio-thermal properties, mechanical attributes, and structural performance of composite metal decks constructed with RAC. The analysis reveals that the inclusion of recycled aggregates has both positive and negative impacts on these elements when exposed to high temperatures. The fire resistance of metal decking composite slabs is significantly influenced by material properties, composition, and RAC mix design. Experimental findings indicate that RAC slabs showed larger midspan deflection under load and fire exposure compared to their counterpart NC slabs. After 120 min. of duration, the mid-span deflection of RAC-0 was recorded to be 19 % higher than the corresponding deflection of NC-0 slab. While temperature-time curves show comparable performance between RAC and natural concrete (NC) slabs, RAC slabs exhibit a notably lower ratio of soffit temperature to the upper surface temperature, resulting in increased spalling. In conclusion, this study advocates for the broader utilization of RAC in constructing structural elements, particularly composite slabs facing extreme temperatures. However, it emphasizes the need for additional research to optimize fire resistance and gain a comprehensive understanding of their behaviour. The findings provide essential guidance for structural engineers and researchers involved in the design of sustainable and fire-resistant structures.

Long-term aerodynamic performance of bridge decks under uncertain wind and turbulence conditions

Long-term aerodynamic performance of bridge decks under uncertain wind and turbulence conditions

Analysis of heat transfer and prediction of preheating time of snow-melting on a highway T-beam bridge deck

Electrical heating is an innovative method of preventing icing of bridge decks during winter. Turning on the heating system before snowfall to prevent the icing of the bridge deck is more advantageous than melting already-formed ice. This article analyzes the heat-transfer performance of a bridge deck with heating cables during preheating before snowfall and predicts the preheating time of the bridge deck. Firstly, the temperature rise law and the state of the bridge deck with heating cables were studied through field experiments. Subsequently, a numerical model was developed. The effects of four factors on the heat-transfer performance of the bridge deck were analyzed. Finally, a bridge deck preheating-time model was established based on a multilayer perceptron regressor. This study enriches the application of neural networks and numerical simulations in preventing ice formation using the electrical heating method and is important for optimizing the heating system scheme and saving energy.

Experimental study on fatigue performance of double welded orthotropic steel bridge deck

Fatigue cracks which develop at multiple locations of orthotropic steel bridge decks (OSD) seriously deteriorate the safety and durability of steel bridges. U-rib fabricated using the double-sided penetration welding technique have been practically applied in bridges, but the fatigue performance of this type of U-rib has not been systematically studied. This study conducts fatigue tests on large-scale models of various fatigue details in the diaphragm area of orthotropic steel bridge decks with double-sided welds, obtaining the fatigue vulnerable locations and dominant cracking modes in the diaphragm area. The evolution law of out-of-plane deformation of diaphragm is clarified. The distribution characteristics of residual stress at the arched opening region and fatigue failure modes are acquired. Experimental results show that the interior weld toe of the U-rib-to-top-plate joint is the most fatigue-vulnerable zone, with a fatigue strength of 53.6 MPa. New fatigue cracks initiated from the weld toe of the top plate of the inner side of the U-rib or the weld toe of the U-rib perpendicularly or obliquely intersecting the longitudinal weld along 45° were found. After 10 million loading cycles, the residual stress in the arc-shaped opening area of the diaphragm reached 90–145 MPa, and the residual stress was higher where curvature of the opening was larger. The arc-shaped incision was in a circling state of tension and compression. It was also found that fatigue cracks that initiated from the weld toe of the diaphragm extended along the weld toe for some length before propagating into the diaphragm.

Experimental study on crack performance of steel and early-age BFRC composite beams in negative moment region

The wet joint interface concrete deck in the negative moment region of steel-concrete composite beams is susceptible to tensile cracking, which compromises the durability of the structure. Herein, a basalt fiber reinforced concrete (BFRC) is proposed to examine the wet joint cracking performance of concrete deck in the negative moment region of steel-concrete composite beams. To this end, four-point bending tests were conducted on seven steel-concrete composite beams to investigate failure modes, crack distribution patterns, load-deflection relationship, and load-crack width relationship. Experimentally, the effects of the wet joint concrete types (BFRC and normal concrete), basalt fiber volume content (0, 0.3%, and 0.6%), and concrete age (28, 14, 7, and 3 days) on their mechanical behavior were performed and discussed. The results showed that typical flexural failure commonly occurred in all specimens under the negative moment, with initial cracks appearing at the wet joint interface. The wet joint concrete with basalt fiber volume content of 0.3% exhibited the highest crack resistance, which resulted in a higher number of cracks, less crack spacing, and more uniform crack distribution in the wet joint concrete deck. The prediction methods of the average crack spacing and crack width of the wet joint concrete were proposed based on the existing theoretical models. The crack width and concrete age influence coefficients were proposed to rationally assess the effects of basalt fiber and concrete age. The modified formulas for the average crack spacing and crack width showed a reasonably good agreement with the experimental results when considering the effects of basalt fiber and concrete age. These formulas can be effectively utilized to evaluate the main crack width at the non-interface joint in the negative moment region of steel-concrete composite beam decks. The proposed approaches can provide a simple and practical method to effectively predict the crack width in the negative moment region of the steel-concrete composite beam.

Effects of Shear Studs and Openings in The Mechanical Performance of Composite Floor Deck using Finite Element Analysis

The composite floor deck system is the most popular floor system used in the construction industry, especially in industrial structures. A composite floor deck is a floor system that consists of a steel deck bonded with concrete. The shear bond between the steel deck and concrete slab normally controls the shear capacity of a composite floor deck system. In the current construction industry, shear studs are normally used to improve the shear performance of the structure. However, the literature review shows that there were very limited studies on identifying the efficiency of these shear studs and their effects on the composite floors' mechanical performance. In addition, there were always openings for M&E equipment in the floor deck system, which needs further analysis to determine their effects on themechanical performance of the composite floor deck system. Thus, the main objective of this study was to identify the effects of shear studs and openings on the mechanical performance of composite floor decks. The method adopted in this study was the Finite Element Analysis (FEA) using ANSYS software. The outcome of the result has shown that the presence of shear studs improves the mechanical performance of a composite floor deck while the presence of openings reduces the mechanical performance of a composite floor deck system.Keywords: composite floor deck, opening, shear studs, mechanical performance

Study on the fatigue performance of steel-composite grillage deck of large-span arch bridge

In this paper, based on the finite element numerical method, an arch bridge with a main span of 252m was selected as the engineering background, and three standard grillage segments of the bridge deck in the derrick area were selected to establish a refined finite element model, and the fatigue characteristics of the steel-composite grillage deck were studied. The fatigue calculation mode III in General Specification for Design of Highway Bridges and Culverts (JTG D60-2015) was loaded into the finite element model for calculation, and the fatigue key points were determined, the stress time course curves were extracted, and the fatigue damage calculation was carried out. The results indicate that the most unfavorable stress point of the steel-composite structure model is at the bottom plate (outside) of the intersection of the middle longitudinal beam and the secondary crossbeam under the longitudinal loading of vehicle load in the transverse position; the stress amplitude of the maximum critical point in the longitudinal bridge stress course under the standard fatigue vehicle model is less than the fatigue strength limit of the normal amplitude, which meets the design requirements.

Treadmill Deck Performance Optimization Design Based on Muscle Activity during Running

In previous research on treadmills, the main focus has been on comparing the physiological differences induced by running on treadmill decks and other exercise surfaces, with relatively little research on the mechanical properties of treadmill decks. Reducing sports injuries is a common desire of runners, which may be closely related to muscle activity. Obviously, the mechanical properties of the treadmill play an important role in this process. Muscle activity was evaluated based on a mass-spring-damper (MSD) model that provides a simulated signal of the ground reaction forces (GRF) and vibration of the lower-limb soft tissues (LLST) during the landing of the human body during running. We improved the original human motion model by considering the stiffness and damping effect of the treadmill deck. In addition, based on the theory of muscle activity regulation, the dimensionless objective function is established, and the particle swarm optimization algorithm is used to find the best range of treadmill deck parameters under pre- and post-fatigue conditions. The results show that the hardness of the treadmill deck can affect the regulation of muscle activity. Based on this, the parameters of the specific safe area of the treadmill deck are obtained, and the size of the safe area after fatigue is significantly reduced compared to that before fatigue. By studying the physiological effects of the mechanical properties of the treadmill deck on runners, the research results are expected to provide references for the design of treadmill deck parameters and reduce the risk of runners’ sports injuries, which has practical application value for treadmill design and runners’ health.

Study on Shear Resistance and Structural Performance of Corrugated Steel–Concrete Composite Deck

This study looks into a new composite bridge deck structure that employs a corrugated steel plate as the base. The goal is to address the shortcomings of traditional deck-bearing capacity, stiffness, and stress performance. Specifically, this study investigates the shear performance and slip characteristics of this structure. To achieve this, the study analyzes the shear behavior and slip tendencies of the composite bridge deck. The study focuses on the role of shear studs and PBL (Perfobond Leiste) perforated steel plates as essential components for shear connections. The shear performance of the composite deck is analyzed based on the structure of shear connection keys such as shear studs and PBL perforated steel plates. The advantages of composite decks in terms of stiffness, self-weight, load-bearing capacity, shear resistance, slip resistance, etc., are discussed to provide a theoretical reference for practical engineering applications. The shear resistance of shear stud shear keys is investigated through shear push-out experiments, and the shear resistance of shear studs is investigated through finite element simulations based on the ABAQUS 2020 finite element software. The results showed that the shear load capacity of the shear studs increased with the increase in the height-to-diameter ratio for different diameters of the shear studs, and the range of increases was from 2% to 23%. However, when the diameter of the shear stud exceeded 22 mm, the ultimate shear capacity of the shear stud increased with the increase in the height-to-diameter ratio, and the magnitude of the increase slowed down. For the actual design of the composite deck, it is recommended to maintain a shear stud height-to-diameter ratio within the range of 9 to 12. When using a composite deck with a PBL open-hole steel plate, the maximum longitudinal slip at the plate end and within the span is only 0.28 mm and 0.0158 mm, respectively. These values are 31% and 36% lower than those of the composite deck with a peg shear key. Additionally, the vertical peeling within the span of the PBL open-hole steel plate is merely 0.46 mm, showing a 21% reduction compared to that of the shear studs. It can be seen that the PBL perforated steel plates are more effective than the shear studs in resisting slip and peel.

Cognitive Processing Disruptions Affecting Flight Deck Performance: Implications for Cognitive Resilience

The flight deck of a commercial aircraft has become progressively digitized and operates in multiple modes with displays and indicators that require increasing levels of comprehension. Examining several aspects of cognitive processing is important to understand how threats to safety might occur and what actions might be taken to reduce severity or to eliminate the threat altogether. This paper presents the elements of cognition to consider, relevant characteristics of working memory and cognitive processing speed, types of disruptions and how they are addressed, results from overload or confusion, and the need for effective cognitive resilience to recover and repair the threat. Data from Aviation Safety Reporting System (ASRS) databases indicate 30% of cases could represent a distinct threat of cognitive overload. These are evaluated to identify sources and likelihood for surprise disruptions and to assess the potential of cognitive resilience. Adaptation of the CRM-TEM model is considered for potential application in training and investigations.

Numerical study on the effects of stud degradation and stud arrangement on the fatigue performance of steel-UHPC composite decks

The fatigue degradation of stud connectors is generally neglected in the fatigue analysis of steel-UHPC composite decks, which may lead to inaccurate results. This paper studies the effects of stud degradation and stud arrangement on the fatigue behavior of steel-UHPC composite decks via finite element analysis. A numerical method for the fatigue analysis of composite decks is proposed considering the fatigue degradation of studs. The numerical method is experimentally validated and applied to evaluate the fatigue performance of composite decks. The effect of stud arrangement on the fatigue response of composite decks is studied by parametric analysis. The results indicated the fatigue degradation of studs and the decrease in stud spacing caused more uniform distribution of shear forces at steel-UHPC interfaces. The fatigue degradation of stud connectors reduced the structural stiffness, while reducing the stud spacing enhanced the local stiffness but increased the stress ranges of some fatigue-critical details. Neglecting the stud degradation could lead to an underestimation of the fatigue life of stud connectors. This study advances the understanding of the fatigue behavior and the ability to analyze the fatigue behavior of steel-UHPC composite decks.