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561.
Wind‐induced inter‐story drift analysis and equivalent static wind load for multiple targets of tall buildings
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J. Y. Fu Q. X. Zheng J. R. Wu Y. Q. Huang 《The Structural Design of Tall and Special Buildings》2016,25(6):297-321
In super high‐rise buildings with varying story heights, the wind‐induced inter‐story drifts might violate the specified limit. However, these effects have seldom been concerned in wind‐induced response analysis. The theory and application of equivalent static wind load (ESWL) for wind‐induced inter‐story drifts of super high‐rise buildings were studied in this paper. A spectral decomposition method suitable for multi‐point excitation problems was firstly proposed. The formula of ESWL targeting for largest inter‐story drift was derived. For more reasonable structural design, the ESWL for multiple targets including displacement atop of building and inter‐story drifts at all story levels is put forward, in which the dominant modal inertial forces are adopted as the based load vectors. The presented methods were finally verified by its application for the wind‐induced response analysis for a tallest super tall building in Guangzhou. The researched results showed that the proposed spectral decomposition method not only has the same precision as the complete quadratic combination method but also possesses higher computation efficiency. The ESWL for multiple targets produces the same static responses for all the specified wind‐induced response, so it is much more rational for wind‐resistant structural design. Meanwhile, it is more reasonable to select the wind‐induced responses in the same direction simultaneously as the targeted values for obtaining the required ESWLs; however, the ESWL targeting for the wind‐induced responses in all degrees of freedom would generate more queer and unrealistic ESWLs distribution. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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A new processing route of thermo‐mechanical processing (TMCP) followed by inter‐critical quenching and tempering (L‐T) was developed to produce 590MPa grade high strength plates based on a relatively lean composition of plain carbon manganese steels microalloyed with Nb, V and Ti. The effect of quenching temperatures on the evolution of microstructure and mechanical properties were investigated. The nano‐hardness measurements of martensite were performed with a nano‐indenter, which indicated that the fractions of as quenched and tempered martensite increased and their hardness values decreased with increasing quenching temperatures in the range from 760 °C to 810 °C. For both as quenched and tempered samples, ferrite grain sizes decreased with increasing quenching temperature in almost linear relationships. The yield strength increased with increasing the fraction of martensite while the tensile strength remained almost unchanged, leading to the increase of yielding ratio with increasing quenching temperatures. The optimum quenching temperature was determined to be around 760 °C in terms of strengths and yield ratio. 相似文献
564.
从无梭织机绞边机构的作用,类型入手,详细介绍了ZA200型喷气织机行星绞边机构的结构,工作原理及工作过程。 相似文献
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数字电视信号都是以加扰的方式传输,模拟的字幕插播系统已不再适应,通过对目前主流的两种字幕插播系统的比较,结合各有线电视网络的实际情况,选择一套合适的字幕插播系统,用于紧急广播、政府宣传、公益广告、广告创收等播出。 相似文献
567.
Three‐dimensional (3D) memories using through‐silicon vias (TSVs) will likely be the first commercial applications of 3D integrated circuit technology. A 3D memory yield can be enhanced by vertical redundancy sharing strategies. The methods used to select memory dies to form 3D memories have a great effect on the 3D memory yield. Since previous die‐selection methods share redundancies only between neighboring memory dies, the opportunity to achieve significant yield enhancement is limited. In this paper, a novel die‐selection method is proposed for multi‐layer 3D memories that shares redundancies among all of the memory dies by using additional TSVs. The proposed method uses three selection conditions to form a good multi‐layer 3D memory. Furthermore, the proposed method considers memory fault characteristics, newly detected faults after bonding, and multiple memory blocks in each memory die. Simulation results show that the proposed method can significantly improve the multi‐layer 3D memory yield in a variety of situations. The TSV overhead for the proposed method is almost the same as that for the previous methods. 相似文献
568.
数字有线电视主要采用QAM调制形式。针对QAM调制信号的特点,在加权多模盲均衡算法的基础上,引入Sigmoid函数的变形,提出了一种加权值随均方误差自适应变化的新算法。新算法不需要设定模式转变的门限值,使算法模式从MCMA随均衡输出自适应转化为DD模式。通过仿真表明该算法与多模盲均衡算法(WMMA)相比降低了仿真复杂度,具有更稳定的收敛性能,适应于高阶QAM信号。 相似文献
569.
Recently, intelligent transportation systems (ITS) is becoming an important research topic. One goal of ITS is to exchange information among vehicles in a timely and efficient manner. In the ITS research community, inter‐vehicle communications (IVC) is considered a way that may be able to achieve this goal. An information network built on the top of vehicles using IVC can be viewed as a type of mobile ad hoc networks (MANETs). In the past, several unicast routing protocols for MANET have been proposed. However, most of them are designed for general MANETs rather than for IVC networks. In this paper, we first used more realistic vehicle mobility traces generated by a microscopic traffic simulator (VISSIM) to understand the characteristics of routing paths in an IVC network. Based on the insights gained from the derived path characteristics, we designed and implemented an intelligent flooding‐based routing protocol for small‐scale IVC networks. Via several field trials conducted on highways, we compared the performance of ad hoc on‐demand distance vector (AODV) and our protocol. Our experimental results show that (1) our protocol outperforms AODV greatly in IVC networks and (2) our protocol can provide text, image, audio, and video services for small‐scale IVC networks (e.g., a platoon) quite well. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
570.