유동-구조 연성해석기법을 이용한 풍하중이 관절형 컨테이너 크레인에 미치는 영향에 관한 연구

Dynamics of container cranes: three-dimensional modeling, full-scale experiments, and identification

Consideration of site specific lateral loading due to wind or earthquake loads along with vertical gravity loads is important for finding the behavior of the tall buildings. As the height of a building becomes taller, the amount of structural material required to resist lateral loads increases drastically. The design of tall buildings essentially involves a conceptual design, approximate analysis, preliminary design and optimization, to safely carry gravity and lateral loads. The design criteria are strength, serviceability and human comfort. The aim of the structural engineer is to arrive at suitable structural schemes, to satisfy these criteria. In the present study, the limit state method of analysis and design of a 3B+G+40-storey reinforced concrete high rise building under wind and seismic loads as per IS codes of practice is described. Safety of the structure is checked against allowable limits prescribed for base shear, roof displacements, inter-storey drifts, accelerations prescribed in codes of practice and other relevant references in literature on effects of earthquake and wind loads on buildings.

The high pier and large-span bridge is high, soft, and have large contact area with the outside world, under the action of wind load, it will occur large vertical and horizontal displacement .This displacement effect on the track structure and will cause rail additional force, lateral displacement and create initial track irregularities, and then reduce the lateral stability of track structure. In this paper, through the large finite element software, we build pier-beam-track model to simulate and analyse the influence on the track structure under the vertical and horizontal wind load, it reached the following conclusion: horizontal wind load basic does not cause rail additional force, but reduce the rail lateral stability; longitudinal wind load can make rail produce certain vertical additional force, but compared to the telescopic additional force, the force basic can be ignored.

Fully coupled analysis of a semisubmersible-type floating offshore wind turbine is carried out for the fatigue damage investigation at tower base by using the code FAST. By combining the axial force and the bending moment, the stress around the circumference can be calculated. This study investigates the effect of second order wave force, wind load, mooring model, and tower elasticity on the stress response at tower base. There are three peaks in the stress amplitude spectrum, corresponding to pitch resonance, wave frequency, and first-order natural mode of the tower, respectively. The first and third peaks are mainly induced by wind load. The effect of the second order wave force and mooring model on the stress seems to be neglectable based on the numerical results. By using the rainflow counting method, the fatigue damage is calculated. The obtained fatigue damage under several environmental conditions indicates that the misalignment and coupling effect of wind and wave loads may significantly affect the total fatigue damage. The wind and wave induced responses are calculated separately (uncoupled method). Next, two superposition methods for fatigue damage calculation are analyzed: fatigue damage superposition and stress superposition. Compared with the fully coupled analysis considering wind and wave together, the former gives lower prediction but the latter seems to provide acceptable results. Finally, considering the long-term wind and wave distribution, the fatigue damage under different environmental conditions is calculated, and the fatigue damage obtained from stress superposition method shows reasonable agreement with that obtained from a fully coupled analysis.

In this paper, the finite element model (726 nodes, 1805 rods) of a 220 kV-GC21D-ZM3 transmission tower is established based on ANSYS APDL. The mechanical response characteristics of the tower under wind load, ice load, and different foundation settlement conditions are systematically studied. The results show that : (1) Under the action of wind load, the displacement of the tower increases with the increase of height, and the maximum equivalent stress is concentrated in the middle of the tower. (2) The coupling effect of icing load and wind load will significantly increase the stress of the bar, and it is necessary to pay attention to the influence of icing in high-altitude areas. (3) The analysis of foundation settlement shows that the relationship between the stress of key members and the settlement of a single tower foundation is linear (slope 3.7305 MPa/mm). Under the condition of uneven settlement of the double tower foundation, the member reaches the yield stress when the settlement is 37.29 mm. The uneven settlement of the three-tower foundation has the most significant effect on the structural stability, and its critical settlement value is the smallest, and the yield speed is the fastest.

During the conversion process of the short-circuit arc to the submerged power supply arc, because the short-circuit arc diameter is much larger than the submerged power supply arc, the specific position of the submerged power supply arc cannot be determined, and the initial position of the submerged power supply arc has a certain randomness. The purpose of this paper is to try to use the binocular stereo vision method to reconstruct the submerged arc image in three dimensions, obtain the moving image of the arc, obtain more comprehensive information than the two-dimensional image, and multi-field coupling dynamics of the power supply arc. In this paper, the multi-field coupling effects of electromagnetic force, thermal buoyancy, wind load and air resistance of the submerged arc of the half-wavelength transmission line are considered comprehensively, and the chain arc model is incorporated into the force equation and motion model of the submerged arc. By deeply analyzing the formation and motion mechanism of the arc root, the arc root model of the submerged power arc is established, and the optimal selection method of the current element length is proposed. The physical simulation experiment of the half-wavelength submerged arc is carried out, and the simulation results are compared with the experimental results to verify the effectiveness of the simulation model. By comparing the trajectory and self-extinguishing time of different submerged currents, wind speeds and winds to the submerged power supply arc, the effects of wind load, thermal buoyancy and electromagnetic force on the arc are analyzed, which indicates that the built arc model can effectively account for the wind load. The influence of submarine power arc motion and self-extinguishing characteristics. The results show that the submarine power arc image is acquired by constructing a binocular stereo vision system, and the obtained submersible arc image is reconstructed three-dimensionally. The three-dimensional image of the arc is obtained and compared with the actual image. The result shows that the three-dimensional reconstruction The result is effective, and the exploration study provides a new method for further obtaining the multiple variations of the true arc length of the arc with the arcing time.

Designing reliable and cost-effective floating bridges for wide and deep fjords is very challenging. The floating bridge is subjected to various environmental loads, such as wind, wave, and current loads. All these loads and associated load effects should be properly evaluated for ultimate limit state design check. In this study, the wind-, wave-, and current-induced load effects are comprehensively investigated for an end-anchored curved floating bridge, which was an early concept for crossing the Bjørnafjorden. The considered floating bridge is about 4600 m long and consists of a cable-stayed high bridge part and a pontoon-supported low bridge part. It also has a large number of eigen-modes, which might be excited by the environmental loads. Modeling of wind loads on the bridge girder is first studied, indicating that apart from aerodynamic drag force, aerodynamic lift and moment on the bridge girder should also be considered due to their significant contribution to axial force. Turbulent wind spectrum and spatial coherence play an important role and should also be properly determined. The sway motion, axial force, and strong axis bending moment of the bridge girder are mainly induced by wind loads, while the heave motion, weak axis bending moment, and torsional moment are mainly induced by wave loads. Turbulent wind can cause significant larger low-frequency eigen-mode resonant responses than the second-order difference frequency wave loads. Current loads mainly contribute damping and reduce the variations of sway motion, axial force, and strong axis bending moment.

The computational fluid dynamics (CFD) and computational structural mechanics (CSM) focus areas at Argonne's Transportation Research and Analysis Computing Center (TRACC) initiated a project to support and compliment the experimental programs at the Turner-Fairbank Highway Research Center (TFHRC) with high performance computing based analysis capabilities in August 2010. The project was established with a new interagency agreement between the Department of Energy and the Department of Transportation to provide collaborative research, development, and benchmarking of advanced three-dimensional computational mechanics analysis methods to the aerodynamics and hydraulics laboratories at TFHRC for a period of five years, beginning in October 2010. The analysis methods employ well-benchmarked and supported commercial computational mechanics software. Computational mechanics encompasses the areas of Computational Fluid Dynamics (CFD), Computational Wind Engineering (CWE), Computational Structural Mechanics (CSM), and Computational Multiphysics Mechanics (CMM) applied in Fluid-Structure Interaction (FSI) problems. The major areas of focus of the project are wind and water effects on bridges - superstructure, deck, cables, and substructure (including soil), primarily during storms and flood events - and the risks that these loads pose to structural failure. For flood events at bridges, another major focus of the work is assessment of the risk to bridges caused by scour of stream and riverbed material away from the foundations of a bridge. Other areas of current research include modeling of flow through culverts to assess them for fish passage, modeling of the salt spray transport into bridge girders to address suitability of using weathering steel in bridges, CFD analysis of the operation of the wind tunnel in the TFCHR wind engineering laboratory, vehicle stability under high wind loading, and the use of electromagnetic shock absorbers to improve vehicle stability under high wind conditions. This quarterly report documents technical progress on the project tasks for the period of July through September 2011.

Numerical study on the sensitivity of photovoltaic panels to wind load on array layout

In this study, the effects of wind and seismic loads on 5, 10, and 15 story steel buildings with different bracing systems were investigated. Linear static and nonlinear dynamic analyses were performed to assess the base shear, base moment, and story drift for all bracing systems. In addition, the cost analysis was taken into consideration. Five structural configurations were used: V-bracing, inverted V-bracing, one-story X-bracing, and multistory X-bracing. One of the most important features of a building is lateral stiffness, which defines the resistance to displacement under seismic and wind loads, at the same time, the lateral stiffness has a major impact on the natural time of the structure. Reducing displacement and cost in the structures indicates that the design is safe and economical. Therefore, the purpose of this article is to find the best bracing system that causes minimum displacement, which indicates maximum lateral stiffness. From this point of view, the behavior of bracing systems exposed to wind and seismic loads in buildings with different stories was investigated. Static linear analysis results showed that the best bracing systems to reduce lateral displacement were the one-story X-bracing system for 5 and 15 story buildings and the V-bracing system for 10 story buildings. On the other hand, nonlinear dynamic analysis results showed that lateral displacement was minimum in unbraced, V-bracing, and one-story X-bracing systems for 5, 10, and 15 stories, respectively.

Contributions to member stresses due to overall wind-induced behaviors of thin-walled cylindrical shell

Wind loads are the primary environment during the usage of power transmission tower. If transmission tower cannot bear the wind loads, the collapsing of transmission tower can lead to the interruption of electric power supply. In this paper, some effects of wind loading on the mechanical response of transmission tower were analyzed by means of commercial finite element software ABAQUS. A narrow based steel lattice transmission tower model was used. A finite element model was established to analyze the truss system. Based on the simulated results, the maximum stress and displacement of transmission tower were achieved for different levels of wind loading. The research indicated the wind loading has an important effect on the mechanical responses of power transmission tower. Both the maximum stress and maximum displacement increase with the increasing level of wind. When the wind level is larger than 12, the power transmission tower could be collapsed.

The increase in the population is at an exponential rate, and the available land is in the form of irregular shapes. That is why irregular shapes are very commonly built. Wind load increases with respect to height, so wind load evolution is necessary for such high-rise structures. Wind forces majorly depend on the plan's cross-sectional shape. Therefore, for an irregular shape, an investigation is needed for tall buildings. This paper demonstrates a detailed study on velocity stream line, external pressure coefficients, pressure distribution on the surfaces of the building and the turbulence kinetic energy for the Y-shaped plan for tall buildings under wind excitation for wind incidence angles of 0o to 180o. k- turbulence model is utilized to solve the problem using computational fluid dynamics techniques in ANSYS for terrain category II as per IS: 875 (Part3), 2015. Wind ward faces in all building models show positive pressure distribution, while the leeward faces are under the effect of negative pressure distribution. Wind load can be reduced on building models by modifying the corners, such as chamfering, rounding, and double recessed. The variation of pressure distribution on different faces of a "Y" plan shaped tall building for 0° and 180° is investigated using ANSYS CFX, and the pressure contours are plotted for all the faces of different "Y" shaped buildings to compute the effect of corner modification on pressure distribution. In this research, it was found that building models with rounded corners are highly efficient in resisting the wind load. Doi: 10.28991/CEJ-2022-08-02-06 Full Text: PDF

This study examines the static performances of a graphene platelet (GPL)-reinforced ethylene tetrafluoroethylene (ETFE) composite membrane under wind loadings. The wind pressure distribution on a periodic tensile membrane unit was analyzed by using CFD simulations, which considered various wind velocities and directions. A one-way fluid–structure interaction (FSI) analysis incorporating geometric nonlinearity was performed in ANSYS to evaluate the static performances of the composite membrane. The novelty of this research lies in the integration of graphene platelets (GPLs) into ETFE membranes to enhance their static performance under wind loading and the combination of micromechanical modelling for obtaining material properties of the composites and finite element simulation for examining structural behaviors, which is not commonly explored in the existing literature. The elastic properties required for the structural analysis were determined using effective medium theory (EMT), while Poisson’s ratio and mass density were evaluated using rule of mixtures. Parametric studies were carried out to explore the effects of a number of influencing factors, including pre-strain, attributes of wind, and GPL reinforcement. It is demonstrated that higher initial strain effectively reduced deformation under wind loads at the cost of increased stress level. The deformation and stress significantly increased with the increase in wind velocity. The deflection and stress level vary with the wind direction, and the maximum values were observed when the wind comes at 15° and 45°, respectively. Introducing GPLs with a larger surface area into membrane material has proven to be an effective way to control membrane deformation, though it also results in a higher stress level, indicating a trade-off between deformation management and stress management.

A novel cost-efficient deep learning framework for static fluid–structure interaction analysis of hydrofoil in tidal turbine morphing blade