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1.
配筋混凝土砌块砌体剪力墙结构是一种新型材料结构体系,其精确分析和计算理论目前还不成熟.用有限单元法的基本理论对配筋混凝土砌块砌体剪力墙进行了非线性分析,并在此基础上编制了c 语言程序.运用该程序对已有的试验进行了分析,结果与试验基本吻合,说明采用此方法对配筋混凝土砌块砌体剪力墙进行分析和计算具有参考价值.  相似文献   

2.
三峡工程水电站进水口的型式及其水力特性   总被引:2,自引:0,他引:2  
主要论述三峡工程电站进水口的型式及其实验结果.三峡电站进水口设计是有两种型式,即单孔方案和双孔方案,每种方案都经过数次体型优化,并对每种优化方案进行了模型试验.本根据试验成果对单、双孔进水口各方案的水力特性进行了综合评述及对比分析,最终得出,双孔方案总比单孔方案的流态更好.在给定的控制条件下,双孔方案进水前不会导致任何的漩涡产生,相反,在单孔方案进水口前出现了挟气漩涡.尽管这处漩涡在单四方案中可以被消除,但是要设置破选措施.试验结果表明,双孔方案增大了电站进水口的面积,但是并没有降低水头损失,两种进口方案有着几乎相同的水头损失,但就某种方案而言,优化过程还是降低了水头损失的.本最后简要评价了ASCE的设计准则。  相似文献   

3.
某水电站导流洞控制段三维有限元分析   总被引:1,自引:0,他引:1  
某水电站导流洞进口控制段过水断面较大,封堵门设计水头达到75.52m,以结构力学方法计算,难以反映结构实际受力情况且配筋量较大.为反映结构应力应变实际情况,利用ANSYS有限元分析软件,建立某水电站导流洞控制段三维模型进行有限元计算,重点分析闸门颈口,边墩,中墩,顶板和底板等部位应力应变情况,为结构设计及结构配筋优化提供依据,也为今后的实际工程提供了有意义的参考.  相似文献   

4.
针对单纯采用压力钢管或内钢衬外包钢筋混凝土管道形式都难以适应超高水头的技术难题,文中提出了双钢衬钢筋混凝土压力管道的结构型式,能使这一问题得到较为合理有效的解决,同时对今后类似工程也有很好的参考价值.由于该结构配置的钢材较多,受力复杂,故此,如何充分利用钢材的强度,减少用钢量成为至关重要的问题.文中正是适应这种要求,分别对不同超高水头作用下压力管道进行优化设计,得到相应的结构优化模型.并对弹性优化模型和弹塑性优化模型进行比较,从而显示出混凝土开裂对钢材的最优配置的影响.  相似文献   

5.
坝下游面钢衬钢筋混凝土管非线性有限元分析   总被引:1,自引:0,他引:1  
采用解析法对某水电站坝下游面钢衬钢筋混凝土压力管道进行初步设计,确定了钢衬厚度和钢筋配置,对其进行整体三维非线性有限元分析,着重研究了在设计荷载作用下,钢衬和钢筋的应力状态以及管周混凝土的开裂特征.采用将非线性有限元分析与规范解析法相结合的方法,先根据非线性有限元计算的结果,分析得到钢衬钢筋混凝土管的钢筋应力,再将其代入规范解析公式,计算出结构的裂缝宽度,并最终提出了满足结构限裂要求的配筋方案.  相似文献   

6.
提出一种采用均匀设计与最小二乘支持向量机相结合的电容层析成像传感器结构参数优化方法.该方法以敏感场均匀度为设计目标,采用均匀设计安排试验,试验因素包括ECT传感器的4个重要参数即:极板张角,绝缘管道材料相对介电常数,管道壁厚,以及屏蔽罩与电容极板间的间距.运用最小二乘支持向量机对试验结果进行回归分析,并用因素轮换法进行寻优计算,从而得出优化的传感器结构参数.结果表明:经过优化的电容成像系统具有较好的成像效果.该方法试验次数少,具有较强的实用性.  相似文献   

7.
为探究处于内涝过程超载状态节点的水流结构及水头损失,基于室内管道节点模型进行了87组不同边界条件的三维构造模型模拟,完成了室内试验与数值模拟的对比验证;采用定性定量分析、数据相关性拟合和π理论研究了孔径比(节点直径Φm和管道直径Φp的比值)、管道坡度、承压水头对节点内水流结构和水头损失的影响。研究结果表明:节点出口处的水量交互是产生水头损失的主要原因;局部水头损失系数K随孔径比的增大而增大,随超载水深、承压水头的增大而减小;通过π理论提出K=f(Re)的求解思路是可行的;两种孔径比节点的K值对坡度变化的响应不同,管道坡度的设计需要考虑节点孔径比的影响。研究成果补充了雨洪耦合模型中的节点水流结构,可为一维管网在节点处的水头损失计算提供经验数值和参考。  相似文献   

8.
提出一种将粒子群算法与正交试验法相结合的组合优化策略.首先,基于粒子群算法对整流器内流道结构进行优化;然后,采用正交试验法对整流器整体结构参数进行优化设计.结果表明:经过优化的单内流道水头损失降至0.170 6 mm,扩散段处涡的数量与回流现象明显减少;整流器整体结构的最佳方案使水头损失降至1.572 4m.主次分析表明:对水头损失影响最大的因素为内流道的分布方式,采用Laws分布可使收集段处截面的速度均匀度提高至90.2%,相较原设计均有较大改善,该组合优化策略可以提高潜水式整流器性能.  相似文献   

9.
建立了潮汐电站厂房浮运结构的优化模型,在浮运结构稳性知识库的基础上,采用混合惩罚函数法对其进行优化设计。利用分部优化与整体优化相结合的原则,无约束极小化采用DFP变尺度法,编制了厂房浮运结构优化设计程序。实例计算结果表明,程序是稳定,收敛的,优化结果是可行的。  相似文献   

10.
应用非线性有限元原理,在正确考虑钢筋和混凝土材料特性的基础上,推导了钢筋混凝土杆单元的切线刚度矩阵.该矩阵考虑了杆单元的材料非线性、几何非线性、轴力二次矩、加载历史、钢筋的粘结滑移和混凝土的裂面效应等因素.编制了相应的结构非线性滞回全过程分析程序,运用该程序对两榀混凝土试验门架在水平反复荷载下的试验结果进行模拟计算,计算值与试验结果吻合良好.本文程序实现了混凝土杆系结构包括下降段在内的非线性滞回全过程分析,为该类结构在低周反复荷载下的抗震性能研究提供一个准确、实用的工具  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
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