Three-dimensional wind load effects and wind-induced dynamic responses of a tall building with X-shape

2009 ◽  
Vol 19 (8) ◽  
pp. 885-900
Author(s):  
Wenjuan Lou ◽  
Mingfeng Huang ◽  
Hu Jin ◽  
Guohui Shen ◽  
C. M. Chan
2019 ◽  
Vol 476 (20) ◽  
pp. 2981-3018 ◽  
Author(s):  
Petar H. Lambrev ◽  
Parveen Akhtar

Abstract The light reactions of photosynthesis are hosted and regulated by the chloroplast thylakoid membrane (TM) — the central structural component of the photosynthetic apparatus of plants and algae. The two-dimensional and three-dimensional arrangement of the lipid–protein assemblies, aka macroorganisation, and its dynamic responses to the fluctuating physiological environment, aka flexibility, are the subject of this review. An emphasis is given on the information obtainable by spectroscopic approaches, especially circular dichroism (CD). We briefly summarise the current knowledge of the composition and three-dimensional architecture of the granal TMs in plants and the supramolecular organisation of Photosystem II and light-harvesting complex II therein. We next acquaint the non-specialist reader with the fundamentals of CD spectroscopy, recent advances such as anisotropic CD, and applications for studying the structure and macroorganisation of photosynthetic complexes and membranes. Special attention is given to the structural and functional flexibility of light-harvesting complex II in vitro as revealed by CD and fluorescence spectroscopy. We give an account of the dynamic changes in membrane macroorganisation associated with the light-adaptation of the photosynthetic apparatus and the regulation of the excitation energy flow by state transitions and non-photochemical quenching.


2021 ◽  
Vol 104 (1) ◽  
pp. 003685042098705
Author(s):  
Xinran Wang ◽  
Yangli Zhu ◽  
Wen Li ◽  
Dongxu Hu ◽  
Xuehui Zhang ◽  
...  

This paper focuses on the effects of the off-design operation of CAES on the dynamic characteristics of the triple-gear-rotor system. A finite element model of the system is set up with unbalanced excitations, torque load excitations, and backlash which lead to variations of tooth contact status. An experiment is carried out to verify the accuracy of the mathematical model. The results show that when the system is subjected to large-scale torque load lifting at a high rotating speed, it has two stages of relatively strong periodicity when the torque load is light, and of chaotic when the torque load is heavy, with the transition between the two states being relatively quick and violent. The analysis of the three-dimensional acceleration spectrum and the meshing force shows that the variation in the meshing state and the fluctuation of the meshing force is the basic reasons for the variation in the system response with the torque load. In addition, the three rotors in the triple-gear-rotor system studied show a strong similarity in the meshing states and meshing force fluctuations, which result in the similarity in the dynamic responses of the three rotors.


2015 ◽  
Vol 23 (9) ◽  
pp. 1548-1568 ◽  
Author(s):  
Shao Renping ◽  
Purong Jia ◽  
Xiankun Qi

According to the actual working condition of the gear, the supporting gear shaft is treated as an elastic support. Its impact on the gear body vibration is considered and investigated and the dynamic response of elastic teeth and gear body is analyzed. On this basis, the gear body is considered as a three-dimensional elastic disc and the gear teeth are treated as an elastic cantilever beam. Under the conditions of the elastic boundary (support shaft), combining to the elastic disk and elastic teeth, the influence of three-dimensional elastic discs on the meshing tooth response under an elastic boundary condition is also included. A dynamic model of the gear support system and calculated model of the gear tooth response are then established. The inherent characteristics of the gear support system and dynamics response of the meshing tooth are presented and simulated. It was shown by the results that it is correct to use the elastic support condition to analyze the gear support system. Based on the above three-dimensional elastic dynamics analysis, this paper set up a dynamics coupling model of a cracked gear structure support system that considered the influence of a three-dimensional elastic disc on a cracked meshing tooth under elastic conditions. It discusses the dynamic characteristic of the cracked gear structure system and coupling dynamic response of the meshing tooth, offering a three-dimensional elastic body model of the tooth root crack and pitch circle crack with different sizes, conducting the three-dimensional elastic dynamic analysis to the faulty crack. ANSYS was employed to carry out dynamic responses, as well as to simulate the acoustic field radiation orientation of a three-dimensional elastic crack body at the tooth root crack and pitch circle with different sizes.


2012 ◽  
Vol 166-169 ◽  
pp. 277-281
Author(s):  
Xiang Dong Xie ◽  
Xuan Wang ◽  
Li Qin

The superstructure and its foundation of a super tall building mega-frame structure are simplified equivalently and continuously to a stiffened-thin-wall tube on semi-infinite elastic subgrade. And the influences of static response on super tall building mega-frame structure caused by changes of frame rigidity are computed and analyzed with the three-dimensional model by semi-analytical approach based on ODE(Ordinary Differential Equation) Solver, considering the interactions of subgrade, foundation and superstructure. Then some valuable conclusions are obtained through analyzing the reasonable results of the numerical example.


2013 ◽  
Vol 6 ◽  
pp. 145 ◽  
Author(s):  
Jan Gustincic ◽  
Lluís M. Garcia-Raffi
Keyword(s):  

2012 ◽  
Vol 446-449 ◽  
pp. 837-840
Author(s):  
Yu Zhao ◽  
Shu Fang Yuan ◽  
Jian Wei Zhang

The underwater structure of power house is major structure under the dynamic loads of unit. The vibration problem is very common in operation. So the structures should have sufficient stiffness to resist dynamic loads of unit. This paper establishes three-dimensional finite element models with finite element analysis software—ANSYS. Dynamic characteristics of the power house and dynamic responses of structure under earthquake are analyzed. The results of the computation show that fluid-solid coupling may be ignored when studying dynamic characteristics of structures of the underground power house.


Author(s):  
Lu Zhang ◽  
Shaohua Wang ◽  
Bing Li

The radial tire belt is composed of multi-layered fiber-reinforced cords with a very complex structure. Restricted by the computing speed, the simplified finite element (FE) tire model with equivalent belt is usually applied in the vehicle dynamic simulation. However, it is always difficult to obtain the material parameters of the equivalent belt. In this paper, a calculation method of equivalent belt material parameters for the simplified FE tire model is proposed based on the three-dimensional (3-D) anisotropic elasticity of the cord reinforced composites. The simulation results of the static radial stiffness, modal characteristics, and dynamic responses for the simplified FE tire model with parameters obtained by the calculation method were compared with experiment results. The results show that the deviation between the experiment and simulation is acceptable, and the validity of the calculation method is verified.


2010 ◽  
Vol 148-149 ◽  
pp. 544-547
Author(s):  
Xun Qian Xu ◽  
Ye Yuan Ma ◽  
Guo Qing Wu ◽  
Xiu Mei Gao

Basing on the coupled vibration theory, dynamic behavior of steel bridge deck thin surfacing under rand moving vehicles is studied. A three-dimensional coupled model is carried out for the steel bridges deck thin surfacing and vehicle. A method based on modal superposition and state space technique is developed to solve dynamic response generated by vehicle-surfacing interaction. The dynamic responses of an actual steel bridge deck thin surfacing are studied. The results show that adding epoxy asphalt as a sub coat can improve interface adhesion strength, which would be designed as the interface layer of steel deck thin surfacing.


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