Lateral Wind Loads Research Articles

Wind-induced creaking noise assessment of 3D full-scale assemblies of drywall system using multi-axis cyclic testing

The lateral wind load applied to high-rise buildings results in movements that can cause creaking noises in drywall partitions with suspended ceiling systems. These noises can be disruptive to the residents and impair the structure’s serviceability. In this study, a sequence of large-scale three-dimensional (3D) experiments was conducted on two assemblies of drywall partitions with a suspended ceiling system to address this serviceability issue. The goal was to explore the 3D response of these assemblies, with a key emphasis on validating the effectiveness of adhesives in mitigating noise introduced by screw fixings, not only for individual walls but also when interacting with neighbouring walls and ceilings, which represent the real-world conditions. The six-degree of freedom (6-DOF) Multi-Axis Substructure Testing (MAST) system at Swinburne University Technology was used to simulate realistic wind load conditions. Two sets of test specimens were constructed using different methods to fix the plasterboard wall lining to the cold-formed steel (CFS) frame, which was rigidly bolted to both the MAST crosshead and the floor below. The first set of specimens (Assembly 1) had the plasterboards screw-fixed to the steel frame, while the second set (Assembly 2) used adhesive-only or a combination of adhesive and screw-fixing methods. Additionally, the instrumentation employed for acoustic measurements was strategically chosen to capture the noise generated by the overall system-level response. This served as a means of validating the serviceability noise experienced by users/occupants. Sound pressure level measurements and an acoustic camera were used simultaneously to identify the noise sources. The creaking noise measurements were compared for different specimens of Assemblies 1 and 2 and the effects of different construction details (e.g. fixing method, plasterboard ceiling lining, etc.) on wind-induced creaking noises were discussed. The results of this study can provide valuable insights for manufacturers and designers to minimize creaking noises in drywall partition systems and propose new construction techniques to improve the serviceability of high-rise buildings.

Simulation analysis and prevention strategies for fatigue fracture of the swivel shaft in concrete pump trucks

During the pumping operation of concrete pump trucks, the swivel shaft primarily withstands a series of complex loads such as bidirectional bending moments and torque (stemming from the self-weight of the boom in the amplitude plane, the self-weight of the concrete; wind load and rotational inertia force in the rotation plane; torque from the delivery pipe and the concrete inside), as well as lateral wind load on the concrete and the impact vibration caused by the flow of concrete. These factors can easily lead to fractures due to the loads exceeding the material load limit of the swivel shaft. This study targets the swivel shaft fracture accidents during the construction process of concrete pump trucks, hypothesizing that the accidents occur due to improper installation angles of the swivel shaft (angle between the oil channel hole and the cylinder axis). Firstly, numerical simulation of the onsite conditions is conducted and compared with the results observed from the actual accidents. Secondly, by fixing the onsite conditions (keeping the boom posture unchanged), a 360° rotational simulation calculation of the fractured swivel shaft is performed to identify the relationship between high stress intervals and the swivel shaft rotation angle and the angle between the second variable oil cylinder axis. Finally, a full-condition calculation is conducted for the boom and the swivel shaft. The results indicate that the high stress area of the swivel shaft does not change with the swivel shaft rotation angle (when the boom is fixed) but is related to the position of the second variable oil cylinder axis and is symmetrically distributed around it. Therefore, adjusting the swivel shaft rotation angle to avoid the high stress area near the symmetry axis of the second variable oil cylinder can prevent the fracture accidents of the swivel shaft.

WITHDRAWN: Out-of-plane push-over testing of masonry wall reinforced with prestressed wedges

Masonry partition walls are vulnerable to lateral loads, including seismic, wind, and concentrated push loads. Various strengthening metal fittings have been proposed to improve lateral load resistance, particularly against seismic loads. This study introduces the use of prestressed wedges as a novel reinforcement method for masonry partition walls to enhance lateral load resistance. The resistance of the masonry partition wall against lateral-concentrated push loads was assessed using an out-of-plane push-over test on specimens sized 2300 × 2410 × 190 mm3. The presence or absence of wedges and wedge spacing were set as variables. The push-over test results showed that both the unreinforced specimen and the specimen reinforced with 300 mm spaced wedges toppled, while the specimen reinforced with 100 mm spaced wedges remained upright. Peak loads were measured to be 0.74, 29.77, and 5.88 kN for unreinforced specimens and specimens reinforced with 100 mm and 300 mm spaced wedges, respectively. Notably, a tighter reinforcement spacing yielded a similar strength, as expected, which was attributed to the increased friction force between the masonry wall and steel frame. The W-series specimens exhibited a trend comparable to that of the displacement ductility ratio. Overall, the findings validate that prestressed wedges improve the out-of-plane strength of masonry partition walls.

Robustness analysis for composite multi‐storey modular buildings subjected to wind loads.

AbstractIn this research, an attempt has been made to evaluate the structural response of multi‐storey composite modular buildings when subjected to lateral wind loads. Finite element (FE) models were developed in Abaqus for a general 10 storey composite modular building, with and without the consideration of lateral load resisting mechanisms of composite shear walls. Concrete filled steel tubular (CFST) columns and composite shear walls were proposed in place of conventional elements to improve the structural resistance, modularity, and construction timeframe. It was observed that under the effect of wind loads, the forces between the modules are transferred primarily by horizontal axial forces. When the effect of sudden module removal is considered along with the wind, the vertical shear forces in the horizontal inter‐module connection increase and the connection becomes critical in shear. Even though the probability of occurrence of critical wind loads and a sudden module loss is rare, it was concluded that the wind forces do not influence the overall stability of the structure in the event of progressive collapse by sudden module removal if an effective lateral load resisting mechanism has been designed.

ИССЛЕДОВАНИЕ ВЛИЯНИЯ ИЗБЫТОЧНОЙ СОЛНЕЧНОЙ РАДИАЦИИ И БОКОВОЙ ВЕТРОВОЙ НАГРУЗКИ НА ОЦЕНКУ ПРОЧНОСТИ КУЗОВА ДВУХЭТАЖНОГО ВАГОНА

Approaches to the analysis of the load-bearing systems of the bodies of double-deck cars, as well as the experience of their operation on domestic railways are analyzed. It is found out that for modern load-bearing structures of bodies with minimum permissible safety margin and stability of elements, it is advisable to pay more attention to specific loads, such as wind and loads associated with excessive solar radiation.
 The method of studying the influence of these factors on the load-bearing capacity of the elements of car body pressure shell is proposed. The method provides for both experimental simulation of exposure of the double-deck car roof with excessive solar radiation in combination with subsequent exposure to repair loads, and carrying out a complex of calculations based on the application of the finite element method (FEM).
 The conducted studies indicate the need for a more precise account of the influence of lateral wind load and excessive solar radiation when assessing the strength of the load-bearing structures of the double-deck car bodies.
 It is shown that the proposed technique makes it possible to take into account these specific loads on the basis of mathematical modeling with confirmation of the results obtained by the data of field experiments.

Experimental and Numerical Flexural–Torsional Performance of Thin-Walled Open-Ended Steel Vertical Pile Foundations Subjected to Lateral Loads

This research investigates the effects of torsional moments on the mechanical behavior of thin-walled open-ended vertical pile foundations subjected to lateral wind loads. The aim of this research is to determine and quantify the errors using traditional design methods and provide more effective alternatives. The warping and torsion effect generated over the piles due to the resultant lateral load impact outside the shear center is analyzed in field tests. Complementarily, a two-dimensional finite element model based on the simple bending stress–strain state, as well as a three-dimensional finite element model considering torsional effects, were implemented and their results analyzed. Finally, a comparative analysis between the in-field lateral loading tests and the finite element model approaches was established by comparing load–displacement curves and using a non-linear Wrinkle model of the soil. Additionally, correlations between the experimental and finite element model errors for the cross-sections pile with a different torsional constant and torsional susceptibility index are shown. From the results, it has been ascertained that the slender thin-walled open-ended pile foundations are particularly sensitive to small load deviations from their center of gravity; this leads to the fact that the slenderer the load and the greater its eccentricity, the more it affects the torsion and warping of the pile. Calculation methodologies usually consider a simple in-plane bending behavior, which leads to errors between 44 and 58% in comparison with the experimental results obtained.

Investigation of the Behavior of Steel Plate Shear Walls Considering Double Corrugated Low-Yield-Point Steel Infill Plate

During the last three decades, interest in the application of steel shear walls has increased worldwide. Steel shear walls are used as stiffened and unstiffened walls. One of the main shortcomings of the steel plate shear wall (SPSW) is the infill plate buckling mainly under lateral wind and seismic loads. One of the useful solutions to prevent lateral buckling is the use of walls with corrugated plates. In this research, the behavior of a steel shear wall consisting of two corrugated plates was investigated in the two material cases of the conventional ASTM A36 steel and the low-yield-point (LYP) steel. The use of steel with low yield strength improves the seismic performance of the steel shear wall system. In this study, the effect of the corrugation angle and aspect ratio of the plate were investigated. The results showed that the effect of corrugation angle on the structural parameters of walls with LYP steel is greater than that of walls with A36 steel. By increasing the corrugation angle from 30° to 60°, the elastic stiffness of A36 and LYP walls decreased about 24 and 36%, respectively, and the response modification factor (Ru) of A36 and LYP walls decreased by about 24 and 56%. The corrugation angle has a lower effect on the ultimate strength and energy absorption. Investigating the effect of aspect ratio showed that increasing the aspect ratio improves the seismic performance of the wall.

Design and Analysis of G+5 Residential Building

Structural analysis is a subject which involves designing, planning to build a perfect building. Basically, each project is different with their design criteria such as incoming load, soil properties, dynamic load, built up area etc.In the present days of improving science and technology, analyzing and designing of a building has been made easy by using ETABS and Auto cad software.Design of residential building by Auto CAD (COMPUTER AIDED DESIGN) and analysis of the building by using ETABS (EXTENDED THREE DIMENSIONAL ANALYSIS OF BUILDING SYSTEM)which includes- generating a structural framing plan, getting model analysis of structure and design of structure.ETABS software helps civil engineers to make their work easy and decreases time necessary for planning.The project going to be done is the design of a multi-storey residential building. The building plan has been drafted using the Auto Cad software by the requirements and available area.The super structure i.e. The building frame has been analyzed and designed using the ETABS software.In the present project G+5 Residential building is going to be analyzed and designed for gravity and lateral (wind and earth quake) loads as per Indian standards.

Multi-Hazard Effects of Crosswinds on Cascading Failures of Conventional and Interspersed Railway Tracks Exposed to Ballast Washaway and Moving Train Loads.

The interspersed railway track is an enhanced timber railway track, spot-replacing damaged wooden sleepers with new concrete sleepers to improve the bearing capacity of existing railway lines. Although this interspersed solution is characterised by low cost and short maintenance time, the interspersed tracks have worse stability than concrete tracks and can deteriorate quickly when exposed to extreme weather conditions such as heavy rains and floods. In many cases, heavy rains and floods are accompanied by strong winds. Ballast washaway can often be observed under flood conditions while the mass of trains is unevenly distributed on two rails due to the effect of lateral wind load and rail irregularities. The current work is the first in the world to investigate the collective multi-hazard effects of ballast washway and uneven axle loads on the vulnerability of conventional and interspersed railway tracks using nonlinear FEM software, STRAND 7. The train bogie is modelled by two sets of point loads. The maximum displacement, bending moment and twists have been studied to evaluate the worst condition. The novel insights will help the railway industry develop proper operations of interspersed railway tracks against naturally hazardous conditions.

Otimização multiobjetivo de outriggers em edifícios altos submetidos a cargas de vento

abstract: This paper aims to investigate a methodology for determining the optimum floor positioning of outriggers (ORs) and belt-trusses (BTs) over tall buildings height. The primary goal is to reduce the maximum lateral drift (MLD) and the core base moment (CBM), individually and concurrently. Furthermore, the influence of these elements on other criteria such as maximum acceleration and natural frequencies are analyzed. Throughout the work, the behavior of the structure is verified when the stiffness ratio of the main elements used in the bracing system (core, perimeter columns, OR, and BT) are varied. Therefore, a three-dimensional model of a tall building under lateral wind load is analyzed, using the finite element method with ANSYS software. The mono and multi-objective optimizations were solved, respectively, by the Nelder-Mead method with the author’s modifications to deal with integer variables and by a utility function. Based on the results, it is concluded that by specifically adding ORs/ORs-BTs in tall buildings the influence on the reduction of the mentioned objectives is extremely relevant, reaching up to 68% for the CBM and 71% for the MLD, depending on the amounts employed.

Experimental Study on Wind Loading Characteristics of Trains under Stationary Tornado-like Vortices

The risk of trains being hit by tornadoes in China continues to increase due to the increasing density of railway lines and the shortening of the train departure intervals and the increasing probability of extreme weather phenomena caused by global climate change. If a train is hit by a tornado, it will cause huge casualties and economic losses, so it is necessary to investigate the tornado-induced effects on trains. A series of rigid-model wind pressure measurement tests on a train car under tornado wind loading were conducted using a tornado-vortex simulator, in order to determine the effects of the distance between the train car and the tornado’s center, the swirl ratio of a tornado-like vortex, and the ground roughness on the wind pressure distributions and wind load characteristics on trains. Apparent discrepancies were observed between tornado-induced wind loading and lateral wind loading obtained from conventional boundary-layer wind tunnel tests. The wind pressure and wind load on the car surface are mainly affected by the combined effects of the aerodynamic flow-structure interaction and the pressure drop accompanying the tornado within 1.5 times the vortex core’s radius, and the impact of tornado-like vortices on the train car is almost negligible as the distance from the train car to the tornado’s center exceeds three times vortex core’s radius. The variation trend of mean/fluctuating pressure coefficients is generally consistent. Large values of fluctuating pressure exist mainly on the top and side surfaces of the train car, especially the side surface proximal to the tornado’s center. The most unfavorable mean sectional side force coefficients were found when the train car is located in the tornado’s core and the largest lift force coefficients at the tornado’s center. The overall side force coefficients peaked when the train car is located at a distance of 1.5 times the tornado’s core radius, whereas the largest lift force coefficients were found when the train car was located at the tornado’s center. The overall distribution patterns of the wind force coefficients of the car under different swirl ratios and ground roughness levels are basically the same. The peak aerodynamic force value increases with increasing swirl ratio, and it decreases as ground roughness increases.

Parametric Study of Lateral Loaded Blade Pile in Clay

The study of the mechanical properties between the pile and soil is limited when an enlarged head is added at the bottom of the pile foundation, which acts as anchor stabilization. This study investigates the blade pile foundation used in a solar panel project, which is subjected to lateral wind load action. The parametrical study is performed through the numerical simulation of the blade pile that is embedded in clay soil. The study considers both the soil modulus and the strength parameter of cohesion and concludes that the blade pile foundation capacity has a positive correlation with both. Moreover, when adding blades to a normal circular hollow section (CHS) pile, if the clay cohesion is less than 35 MPa, the capacity improvement rate will be greater. It analyzes the simulated load versus the soil displacement by considering clay in the soil states of very soft, soft, firm, stiff, very stiff and hard. This study finds that the blade application increases the lateral capacity of the pile foundation. In addition, when the soil is very soft to firm, adding blades results in a higher percentage of capacity improvement, which is up to 14.8% for the standard 1.5-m CHS pile with an outside diameter of 76.1 mm.

PDEM-based stochastic analysis of a train-track-bridge system using dimension-reduced simulations of turbulent winds and track irregularities

Winds and track irregularities are inherently random in nature, but most of previous work did not fully consider this randomicity in computation of the dynamic response of train-track-bridge system. This study aims to develop an effective framework for stochastic analysis of the wind-train-track-bridge system based on the probability density evolution method. A dimension-reduced simulation scheme is applied since the involved system has high-dimensional random variables. Therefore, the representative samples of turbulent winds and track irregularities can be well expressed with only two random variables. In numerical examples, the accuracy of the framework is verified, and the influences of the mean wind velocity on the random vibration characteristics of the system are investigated. The results show that the dispersion of the lateral displacement of the bridge is larger than the vertical displacement, but both the vertical and lateral accelerations of the bridge have larger dispersions. The existence of lateral wind loads can reduce the dispersion of the lateral wheel–rail interaction forces of the wheel in the leeward direction. Considering the confidence levels of 75%, 85% and 95%, the train can run safely over the bridge in the wind velocity range of 0–25 m/s.

Research on shear performance of corrugated steel plate shear walls with inelastic buckling of infilled plates under lateral loads

The corrugated steel plate shear wall (CoSPSW) system has potential in resisting lateral wind and seismic loads in high-rise buildings. This paper presents a numerical and theoretical investigation of the shear behaviour of CoSPSWs with inelastic buckling mode of the corrugated steel plate (CSP) subjected to lateral loads. The geometry parameters of CoSPSWs with inelastic buckling of infilled plates were derived theoretically. In addition, a series of finite element analyses was conducted to simulate the performance of CoSPSWs. Parametric analyses were performed to examine the effects of key geometry parameters, such as the height–thickness ratio, aspect ratio, horizontal panel width, and corrugation angle, affecting the buckling and failure modes and the strength of CoSPSWs. Then, the demand of the surrounding frame stiffness of the CoSPSWs was investigated based on the tension field distribution of CSPs. Finally, a modified strip model was designed to predict the shear performance of the CoSPSWs. The results revealed that the CoSPSWs, owing to the tension field effect, could resist greater loads after the inelastic buckling of infilled plates. However, the height–thickness ratio and aspect ratio should be restricted during the design of tall buildings. In addition, a formula for predicting the stiffness demand of the CoSPSW was derived. The results of the modified strip model agreed well with the previous experimental data.

КОМПЬЮТЕРНОЕ МОДЕЛИРОВАНИЕ ДИНАМИКИ ВЗАИМОДЕЙСТВИЯ КОЛЕСНЫХ ПАР ВАГОНОВ С ТОРМОЗНЫМИ БАШМАКАМИ

The paper considers the problem of keeping cars from rolling away on station railway tracks with a permissible slope of 0–2.5 ‰. The study presents the computer simulation results for the dynamic interaction of wheels with brake shoes installed on rails in the process of stopping a freight train car using standard brake shoes in the MSC.ADAMS engineering software package. In this case, various properties of the rail surface were taken into account, simulating favorable and unfavorable conditions for contact between the wheel, brake shoe and rail at braking due to both weather conditions and the peculiarities of station tracks location and operation. The interaction of the car wheels with the maximum axle load and the station brake shoes installed on the rails was studied at different initial velocities of the vehicle movement, as well as when it is at rest on tracks with the permissible slope under the conditions of ensuring the minimum friction between the wheel and the rail, as well as the interaction of rail and shoe was analyzed, which corresponds to the presence of the train on oily rails. It is demonstrated that it is not always possible for one brake shoe put on the oily rail to hold the train moving with the initial velocity more than 0.5 m/sec. Under other conditions of the wheel-brake shoe collision, the problem of keeping the train on the rails is also possible, due to such random factors as lateral wind load, rail icing, wear and deformation of the wheel surface and brake shoe, which reduce the dynamic friction coefficient between the contacting surfaces.

Analytical Comparison of Composite and Non-Composite through Type and Deck Type Steel Truss Bridges

In trusses, deck type and through type truss systems are generally provided with various member arrangements. To utilize the materials used in the trusses more efficiently, RCC decks are nowadays made composite with the truss members. In this paper, analysis of 72.0 m deck type and through type, non-composite and composite bridges is presented. The bridges are modelled using STAAD. Pro v8i software with truss members as beam element and deck slab modelled as four noded plate element. The loading on the bridge is done as per the provisions of IRC-6 and IRC-24. The composite deck effectively reduces the horizontal deflections due to lateral seismic and wind loads in both the truss systems. Decrement in vertical deflection of the truss system was also observed making the structure mode stiffer. Stresses in the members made composite with the deck slab were also reduced and hence resulted in material saving and decreased steel offtake. In the case of composite deck type bridges due to load sharing by the deck slab, the stresses in the top chord are reduced significantly hence eliminating the chances of buckling. Advantages of composite deck are better utilized in deck type bridge system compared to through type bridge system.

Bearing behaviour of aluminium sub-heads with removable beads in façade systems

Occupying a substantial proportion of the overall building expense, building envelopes are the subject of ongoing research and improvement in both aesthetic and structural aspects. The aluminium window wall frame, consisting of vertical members (mullions) and horizontal members (head and sill transoms), is placed between sub-heads at the top and sub-sills at the bottom of the wall. These window walls are designed to carry lateral wind loads. Of particular importance to design stability is the bearing behaviour of aluminium sub-heads. The bearing behaviour and capacities of C-shaped sub-heads were recently investigated through a detailed experimental study at Griffith University for the development of strength prediction equations. To allow for easier assembly of façade panels, a kind of sub-head section known as sub-head with removable bead is used in aluminium window wall system. Two parts of this sub-head are connected together without any external mechanisms. The present research places emphasis on assessing the bearing behaviour of aluminium sub-heads with removable beads through comprehensive experimental testing. A total of 36 tests were conducted using six section geometries, two engagement lengths, and three bearing widths. The bearing strengths obtained from tests of aluminium sub-heads with removable beads were compared with the bearing capacities predicted using the design rules developed by the authors for conventional C-shaped aluminium sub-heads and available cold-formed steel design provisions (AISI S240 2015, TI 809-07, and SSMA 2000 specifications). As a result of the investigation, the current design equations were found to be unreliable for estimating the bearing capacity of aluminium sub-head sections with removable beads. Hence, new design expressions have been developed which accurately predict the strengths of aluminium sub-heads with removable beads under out-of-plane loads. Furthermore, the influence of the removable beads on the bearing behaviour and capacity is discussed in detail.

Structural performance of superframed conjoined towers

SummaryTall buildings have generally been developed as solo towers. As tall buildings become ever taller, how to produce reasonably increased structural depths against lateral wind loads and maintain desirable lease depths simultaneously are critical design considerations. Conjoined towers have great potential to resolve these structural and architectural design issues holistically. While many different structural configurations are possible for conjoined towers, the concept of superframed conjoined towers is a viable option for superior performance. In the superframed conjoined towers studied in this paper, multiple braced tube towers are connected also with horizontal braced tube link structures. Various parameters of the link structures, such as stiffness, numbers, and locations, impact the structural performance of the superframed conjoined towers. As the structural design of tall buildings is generally governed by lateral stiffness, this paper investigates the lateral performance of superframed conjoined towers with variously configured link structures. While emphasis is placed on static responses in relation to architectural design, basic dynamic properties are also studied.

Post-earthquake fire behavior and performance-based fire design of steel moment frame buildings

This paper presents an assessment of steel buildings subjected to post-earthquake fire, illustrated through the implementation of a ten-story case study building, which was designed in accordance with U.S. design codes. The building is located in a high seismic region (Los Angeles, CA), and designed for the associated seismic hazard levels using perimeter special moment frames (SMFs) to resist lateral (wind and seismic) loading and gravity interior frames with composite floor systems to resist gravity (dead and live) loading. The entire 3D building structure was idealized and analyzed using finite element models capable of modeling inelastic deformations, instability failures, and connection damage due to earthquakes and fire. The building models were subjected to eleven earthquakes followed by three different fire scenarios to simulate the effects of post-earthquake fires. The results from post-earthquake fire analyses were used to assess the impact of earthquake-induced damage on structural behavior and stability during fire. Assessments indicate that, for the type and design of structure considered in this research, earthquake-induced damage is generally limited to the perimeter moment frames and has limited influence on post-earthquake fire performance, which is governed by the strength and stability of gravity columns and floor systems. Analytical parametric studies were conducted to further assess and develop performance-based design guidelines for improving structural behavior and stability during post-earthquake fires. These studies indicate that partial or full collapse of the building structure can be prevented by sufficiently increasing the structural design (size) or fire protection (fireproofing thickness) of the critical gravity columns.

Cyclic response of monopile-supported offshore wind turbines under wind and wave loading in sand

Monopiles are popular solutions as the foundation to support offshore wind turbines (OWTs), which suffer from various amplitudes of continuous lateral cyclic wind and wave loading. The accumulation of tilt and change of the natural frequency of OWTs under cyclic loading have become crucial issues for OWT design. Hence the monopile-tower-soil system was established at the small-scale level based on similarity laws with a suit of constant-amplitude and multi-amplitude tests in dense sand. Two sets of gear-driving assembly were successfully set up to achieve the application of cyclic loading to the model OWT. The amplitude and symmetry of cyclic loading were specified as three indicative regions according to those of real wind farms. On the basis of test results, the two-way loading was found to be the most hazardous situation and the preloading condition led to a high accumulation of tilt. The change of natural frequency was controlled by the load magnitude and tended to increase during cyclic loads, while a sharp decrease was observed when sand subsidence was generated. The post-cyclic lateral capacity seemed to be a slight increase compared with the static capacity. The relevant analyses based on test results can provide practical recommendations for OWT design.