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91.
The object of study is a stationary Gaussian white noise excited multi-degree-of-freedom (MDOF) linear elastic, ideal plastic, linearly damped, statically determinate oscillator with several potential elements of ideal plastic yielding. Specifically the study is exemplified for a plane multistory shear frame with rigid traverses where all the connecting columns except the columns in one or more of the bottom floors have finite symmetrical yield limits. The white noise excitation acts on the mass of the first floor making the movement of the elastic bottom floors simulate a ground motion that interacts with the structure above the bottom floors. The method of study is so-called Slepian model simulation and is in principle the same for other statically determinate MDOF elasto-plastic oscillators of the considered type. The method is fast as compared to direct simulation and provides results that give good insight in the behavior of the plastic displacement response process. 相似文献
92.
框架结构焦仓的定向倒塌爆破 总被引:4,自引:1,他引:3
介绍了框架结构焦仓定向爆破拆除的设计与施工,着重介绍了爆破参烽的选取及安全防护措施。达到预期的爆破效果。 相似文献
93.
安塞低渗油田孔隙结构对渗流特征曲线的影响 总被引:22,自引:4,他引:18
渗流曲线的测定是认识油藏流体渗流规律的基础。实验发现安塞油田储集层岩心渗流曲线在低有效净围压下近似表现为两段直线,通过压汞实验和毛管压力曲线数据分析,认为这种特征与储集层孔隙结构有关。在分析渗流特征时应综合考虑孔隙结核特征、流体与孔隙介质的相互作用等因素。 相似文献
94.
Randall Billi; Moss Helen E.; Rodd Jennifer M.; Greer Mike; Tyler Lorraine K. 《Canadian Metallurgical Quarterly》2004,30(2):393
Patients with category-specific deficits have motivated a range of hypotheses about the structure of the conceptual system. One class of models claims that apparent category dissociations emerge from the internal structure of concepts rather than fractionation of the system into separate substores. This account claims that distinctive properties of concepts in the living domain are vulnerable because of their weak correlation with other features. Given the assumption that mutual activation among correlated properties produces faster activation in the normal system, the authors predicted a disadvantage for the distinctive features of living things for unimpaired adults. Results of a speeded feature verification study supported this prediction, as did a computational simulation in which networks mapped from orthography to semantics. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
95.
This paper is a summary of an extensive research program carried out by the authors on the structure of rapidly solidified aluminum alloys; and a comparison with the work of others also involved in this field. The paper discusses the changes in the dendritic and non-dendritic structure of the matrix at cooling rates from 10–3 to 1010 K/s and discusses the hetergeneity of the structure caused by interdendritic-segretion during solidification. 相似文献
96.
97.
本文探讨了装药结构中空气间隙作用的机理,提出了气体分子的迁移效应与碰撞效应,比较完满地解释了不同空气间隙对爆破效果的影响. 相似文献
98.
介绍了养马岛大桥钢管拱肋支撑架的设计与施工,从设计方案的比选、施工技术等方面进行了论述,指出该桥使用此种支架施工,保证了质量,降低了成本。 相似文献
99.
Ramon R. Costa Liu Hsu 《International Journal of Adaptive Control and Signal Processing》1992,6(1):19-33
A variable structure model reference adaptive controller (VS-MRAC) using only input and output measurements was recently proposed and shown to be globally asymptotically stable with superior transient behaviour and disturbance rejection properties. In this paper a singular perturbation approach is used in order to establish the robustness of the controller in the presence of unmodelled dynamics (parasitics) and disturbances. We develop a new Lyapunov-based technique to analyse the overall system and show that for sufficiently small parasitics the system remains stable and the output error is small in some sense. 相似文献
100.
Rein Smedinga 《Discrete Event Dynamic Systems》1993,2(3-4):265-297
To model qualitative aspects of discrete event systems, i.e., the order of the events is of sole importance, we use a triple consisting of the set of all possible events (the alphabet), the set of all behavior (possible strings of events), and the set of all tasks (completed behavior). We use this view to model synchronous as well as asynchronous connection of systems. Moreover, it is easy to define notions like deadlock and livelock in this view. We give a method to construct a second system that, in connection with the original system, gets rid of its deadlock and/or livelock. A state-space representation is introduced. In this representation computations can be done effectively. 相似文献