gw异形柱与短肢剪力墙结构设计中的几个问题.doc

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1、Manipulator is now used as a industrial robots in use, the control objectives often appear often in industrial automation. Industrial automation technology has gradually matured, as mature a technology line has been rapid development in industrial automation as a separate subject. Manipulator applic

2、ation began to filter into welding, logistics, mechanical processing, and other industries. Especially at high or very low temperatures, full of poisonous gases, high radiation case, robot in similar circumstances showed great use also brings great convenience to the staff. Precisely because of this

3、 robot to get peoples attention began to be a high degree of development. Labor rates, working conditions, labor intensive aspects of promoting development. Both at home and abroad to develop the PLC (programmable logic controller) is in various special circumstances and under special conditions set

4、 for mechanical devices. Now turned on the development of the microelectronics automatic control technology and the rapid development of the trains, the success of PLC hardware software and simulation control win big and successful development, now continues to develop as a factory automation standa

5、rds. Because robots are good development of the technology makes a good optimization of productive capital, and robot shows this unique advantages, such as: has good compatibility, wide availability, hardware is complete, and programming that can be mastered in a short time, so in the context of ind

6、ustrial PLC applications became ubiquitous. Manipulator in many developed country agriculture and industry has been applied, such as the use of mechanical harvesting large areas of farmland, repeated operations on the high-speed line that uses a robotic arm, and so on. Today, the high level of autom

7、ation combined with restrictions on the manipulator development level is slightly lower than the international. The design is mainly arm welding machine by PLC Automation control. This of design let designers on in school by learn of has a must of consolidation, understand has some usually didnt opp

8、ortunities awareness in world range within some leading level of knowledge has has must awareness, hope designers can in yihou of design in the can success of using in this design in the proceeds of experience 1.2 manipulator in both at home and abroad of research profile automation mechanical arm r

9、esearch began Yu 20th century medium-term, after years with with computer and automation technology of development, Makes mechanical arm on the Grand stage of industrial automation and shine, gradually became an industrial evaluation standards, and its importance can be seen. Now original robotic ar

10、m spent most of mass production and use on the production line, which is programmed robotic arm. As the first generation of manipulator position control systems main features, although not back several generations that can detect the external environment, but can still successfully complete like wel

11、ding, painting, delivery as well as for materials simple movements. Second generation mechanical arms are equipped with sensors and manipulators have the environment there is a certain amount of sense, when the mechanical arm is to use the program as a basis. Difference is that the robot begand异形柱与短

12、肢剪力墙结构设计中的几个问题摘要： 对异形柱与短肢剪力墙结构设计中的一些 问题 ，如 计算 方法 、异形柱受力性能及其轴压比控制、短肢剪力墙结构中转换层的设置高度及框支柱等进行探讨，提出建议，供结构设计人员 参考 。 关键词： 异形柱 短肢剪力墙 结构设计 现代 住宅建筑要求大开间，平面及房间布置灵活、方便，室内不出现柱楞、不露梁等。异形柱与短肢剪力墙结构能较好地满足现代住宅建筑的要求，因而逐渐得到了推广 应用 。 目前 ，现行国家规范或规程中尚未给出有关异形柱与短肢剪力墙结构设计的条款，因此，结构设计人员在设计中常会遇到一些规范或规程尚未论及的问题，需要设计人员积累经验，利用正确的概念进行设

13、计。 本文旨在对异形柱与短肢剪力墙结构设计中的一些问题进行探讨，提出个人看法，供结构设计人员参考。 1 异形柱结构型式及其计算 异形柱结构型式有异形柱框架结构、异形柱框架剪力墙结构和异形柱框架核心筒结构。 异形柱结构自身的特点决定了其受力性能、抗震性能与矩形柱结构不同。由于异形柱截面不对称，在水平力作用下产生的双向偏心受压给承载力带来的 影响 不容忽视。因此，对异形柱结构应按空间体系考虑，宜优先采用具有异形柱单元的计算程序进行内力与位移 分析 。因异形柱和剪力墙受力不同，所以计算时不应将异形柱按剪力墙建模计算。 当采用不具有异形柱单元的空间分析程序（如 TBSA 5.0）计算异形柱结构时，可按

14、薄壁杆件模型进行内力分析。 对异形柱框架结构，一般宜按刚度等效折算成普通框架进行内力与位移分析。当刚度相等时，矩形柱比异形柱的截面面积大。一般，比值（ A 矩 A 异 ）约在1.10-1.30之间 1 。因此，用矩形柱替换后计算出的轴压比数值不能直接应用于异形柱，建议用比值（A 矩 A 异 ）对轴压比计算值加以放大后再用于异形柱。 对有剪力墙（或核心筒）的异形柱结构，由于异形柱分担的水平剪力很小，由此产生的翘曲应力基本可以忽略，为简化计算，可按面积等效或刚度等效折算成普通框架剪力墙（或核心筒）结构进行内力与位移分析。按面积等效更能反映异形柱轴压比的情况，且面积等效计算更为简便。但应注意，按面积

15、等效计算时，须同时满足下面两式： (1)A 矩 =A 异 ；(2)b/h=(I x异 I y异 ) 1/2 式中， A 矩 、A 异 分别为矩形柱和异形柱的截面面积； b、h分别为矩形截面的宽和高； I x异 、I y异 分别为异形柱截面x、y向的主形心惯性矩。 一般，按面积等效计算时，矩形柱的惯性矩比异形柱的小。但对有剪力墙（或核心筒）的异形柱结构，计算分析表明 2 ，按面积等效与按刚度等效的计算结果是接近的。 异形柱的截面设计，可根据上述方法得出的内力，采用适合异形柱截面受力特性的截面计算方法进行配筋计算。 2 短肢剪力墙结构及其计算 短肢剪力墙结构是适应建筑要求而形成的特殊的剪力墙结构。

16、其计算模型、配筋方式和构造要求均同于普通剪力墙结构。在 TAT、TBSA中，只需按剪力墙输入即可，而且TAT、TBSA更适合用来计算短肢剪力墙结构。TAT、TBSA所用的计算模型都是杆件、薄壁杆件模型，其中梁、柱为普通空间杆件，每端有个自由度，墙视为薄壁杆件，每端有个自由度（多一个截面翘曲角，即扭转角沿纵轴的导数），考虑了墙单元非平面变形的影响，按矩阵位移法由单元刚度矩阵形成总刚度矩阵，引入楼板平面内刚度无限大假定减少部分未知量之后求解，它适用于各种平面布置，未知量少，精度较高。但是，薄壁杆件模型在分析剪力墙较为低宽、结构布置复杂（如有转换层）时，也存在一些不足，主要是薄壁杆件 理论 没有考虑

17、剪切变形的影响，当结构布置复杂时变形不协调。而短肢剪力墙结构由于肢长较短（一般为墙厚的-倍），本身较高细，更接近于杆件性能，所以，用TAT、TBSA计算短肢剪力墙结构能较好地反映结构的受力，精度较高。 对设有转换层的短肢剪力墙结构，一般都只是将电梯间、楼梯间、核心筒和一少部分剪力墙落地，其于剪力墙框支。框支剪力墙是受力面向受力点过渡，由于薄壁杆件的连接处是点连接，所以用薄壁杆件模型不能很好地处理位移的连续和力的正确传递。因此，带有转换层的短肢剪力墙结构宜优先采用墙元模型软件（如 SATWE）进行计算。当然，从整体上的内力（特别是下部支承柱的内力）分布情况来看，如果将剪力墙加以适当的处理，还是可

18、以用TAT、TBSA对结构进行整体计算的 3 。 3 异形柱的受力性能及其轴压比控制 天津大学的试验 研究 结果表明 4 ：异形柱的延性比普通矩形柱的差。轴压比、高长比（即柱净高与截面肢长之比）是影响异形柱破坏形态及延性的两个重要因素。 异形柱由于多肢的存在，其剪力中心与截面形心往往不重合，在受力状态下，各肢产生翘曲正应力和剪应力。由于剪应力，使柱肢混凝土先于普通矩形柱出现裂缝，即产生腹剪裂缝，导致异形柱脆性明显，使异形柱的变形能力比普通矩形柱降低。 作为异形柱延性的保证措施，必须严格控制轴压比，同时避免高长比小于（短柱）。控制柱截面轴压比的目的，在于要求柱应具有足够大的截面尺寸，以防止出现小

19、偏压破坏，提高柱的变形能力，满足抗震要求。广东规程按建筑抗震设计规范（ GBJ1189）中所规定的柱子轴压比降低0.05取用（按截面的实际面积计算）；天津规程则根据箍筋间距与主筋直径之比、箍筋直径及抗震等级共同确定，其要求比广东规程严格，例如，对s/d、（即箍筋间距s100mm，纵筋直径d分别为20mm、25mm的情况），箍筋直径d v 8mm，抗震等级为三级的L形截面，其轴压比限值分别为0.60，0.65。异形柱是从短肢剪力墙向矩形柱过渡的一种构件，柱肢截面的肢厚比（即肢长肢宽）不大于。高规（JGJ391）第5.3.4条，“抗震设计时，小墙肢的截面高度不宜小于3b w ”，“一、二级剪力墙的

20、小墙肢，其轴压比不宜大于0.6”。根据上述分析，为便于应用，建议在度设防区，对于异形柱框架结构，L形截面柱的轴压比不应超过0.6（按截面的实际面积计算，下同），T形截面柱的的轴压比不应超过0.65，十字形截面柱的轴压比不应超过0.8；对于异形柱框架剪力墙（或核心筒）结构，由于框架是第二道抗震防线，所以框架柱的轴压比限值可放宽到0.65（L形）、0.70（T形）、0.90（字形），但对于转换层下的支承柱，其轴压比仍不应超过0.60。 短柱在压剪作用下往往发生脆性的剪切破坏，设计中应尽量避免出现短柱。根据高长比不宜小于，在梁高为 600mm的前提下，当标准层层高为3.0m时，异形柱的最大肢长可为6

21、00mm；底层层高为4.2m时，肢长可为900mm。 4 短肢剪力墙结构中转换层的设置高度及框支柱 在现代高层住宅的地下室和下部几层，由于停车和商业用房需较大空间，就得通过转换层来实现。在短肢剪力墙结构中，一般都只将电梯间、楼梯间、核心筒和一少部分剪力墙落地，其于剪力墙框支。 据研究表明 5 ，“框支剪力墙结构当转换层位置较高时，转换层附近层间位移角及内力分布急剧突变，内力的传递仅靠转换层一层楼板的间接传力途径很难实现；转换层下部的框支结构易于开裂和屈服，转换层上部几层墙体易于破坏。这种结构体系不利于抗震。高烈度区（度及度以上）不应采用；度区可以采用，但应限制转换层设置高度，可考虑不宜超过层；

22、度区可适当放宽限制。”因此，建议在度抗震设防区，短肢剪力墙结构中转换层设置高度不宜超过层，避免高位转换。转换层上下的层刚度比宜接近，不宜超过。转换层位置较高时，宜同时控制转换层下部“框支”结构的等效刚度（即考虑弯曲剪切和轴向变形的综合刚度），使 E g J g 与E c J c 接近。E g J g 为剪力墙结构的等效刚度，剪力墙结构高度取框支层的总高度，其平面和层高与转换层上部的剪力墙结构相同；E c J c 为转换层下部“框支”结构的等效刚度。研究表明 5 ，“控制转换层下部框支结构的等效刚度对于减少转换层附近的层间位移角和内力突变是十分必要的，效果也很显著。” 规范对框支柱的内力、轴压比

23、、配筋等的要求都严于普通柱。框支剪力墙结构当转换层位置较高时，如何定义框支柱，涉及到安全与 经济 的问题。根据圣维南原理，局部处理的影响只限于局部范围，所以当转换层位置较高（如高位转换）时，除转换层附近楼层的内力较复杂外，下面的结构受到的影响很小，应与普通框架结构基本一样，不必按框支柱处理。 文献 计算了两个 28层的结构，一为内筒外框架结构，一为内筒外框支结构，转换层设在18层。计算结果表明，转换层下二层的内力影响很大，下三层的内力误差最大为15%，下五层的内力已比较接近（最大误差小于10%）,下八层的内力已基本一样（最大误差小于5%）。这说明框支柱只需在五层范围内加以考虑，其它层的柱子按普

24、通框架柱处理即可。因此，建议当转换层位置不超过五层时，转换层下的各层柱均按框支柱处理；当转换层位置超过五层时，转换层下相邻的五层柱按框支柱处理，而其它层的柱按普通框架柱处理。由于高位转换对抗震不利，所以结构设计中应尽量避免高位转换。 5 短肢剪力墙结构的抗震薄弱环节及概念设计 振动台模拟地震试验结果表明 7 ，建筑平面外边缘及角点处的墙肢、底部外围的小墙肢、连梁等是短肢剪力墙结构的抗震薄弱环节。当有扭转效应，建筑平面外边缘及角点处的墙肢会首先开裂；在地震作用下，高层短肢剪力墙结构将以整体弯曲变形为主，底部外围的小墙肢，截面面积小且承受较大的竖向荷载，破坏严重，尤其“一”字形小墙肢破坏最严重；在

25、短肢剪力墙结构中，由于墙肢刚度相对减小，使连梁受剪破坏的可能性增加。因此，在短肢剪力墙结构设计中，对这些薄弱环节，更应加强概念设计和抗震构造措施。例如，短肢剪力墙在平面上分布要力求均匀，使其刚度中心和建筑物质心尽量接近，以减小扭转效应；适当增加建筑平面外边缘及角点处的墙肢厚度（宜取 250mm，对底部外围的小墙肢根据需要可取用300mm），加强墙肢端部的暗柱配筋，严格控制墙肢截面的轴压比不超过0.6，以提高墙肢的承载力和延性；高层结构中连梁是一个耗能构件，连梁的剪切破坏会使结构的延性降低，对抗震不利，设计时应注意对连梁进行“强剪弱弯”的验算，保证连梁的受弯屈服先于剪切破坏；短肢剪力墙宜在两个方

26、向均有梁与之拉结，连梁宜布置在各肢的平面内，避免采用“一”字形墙肢；短肢剪力墙底部加强部位的配筋应符合规范要求；等。 参考 文献 ： 戴教芳多层框架异形柱设计探索 J. 工业 建筑,1996,26(1):33-35. 龙卫国异形柱受力性能及结构设计有关 问题 探讨 J四川建筑，2000,20(2):50-52. 赵玉祥钢筋混凝土高层建筑设计中若干问题的探讨 J建筑结构学报.1998，19(2):12-22. 赵艳静等钢筋混凝土异形截面双向压弯柱延性性能的 理论 研究 J建筑结构.1999,29(1):16-21. 徐培福等转换层设置高度对框支剪力墙结构抗震性能的 影响 J建筑结构.2000,3

27、0(1):38-42. 肖文韬等高层建筑结构 计算 模型的选取第五届全国高层建筑抗震技术交流会论文集 S.桐庐，1995.11 程绍革等高层建筑短肢剪力墙结构振动台试验研究 J 建筑 科学 .2000,16(1):12-16.(SnCl2 2H2O), Add hydrochloric acid to dissolve and dilute to 100mL to join the metal Tin particles. 10.10 HCL (1+1): volume 50mL, diluted with water to 100mL hydrochloride. 10.11 lead ac

28、etate solution (100g/L). 10.12 lead acetate cotton: with lead acetate solution (100g/L) after the soaked cotton wool, in addition to the extra solution and loose, at 100 dry, store in glass bottles. 10.13 the sodium hydroxide solution (200g/L). 10.14 sulfuric acid (6+94): volume take 6.0mL sulfuric

29、acid added Yu 80mL water in the, cold Hou again added water diluted to 100mL 10.15 two b base II sulfur generation amino carboxylic acid silver-three ethanol amine-three chlorine methane solution: said take 0.25G two b base II sulfur generation amino carboxylic acid silver (C2H5) 2NCS2Ag placed mort

30、ar in the, added few three chlorine methane grinding, moved people 100mL graduated cylinder in the, joined 1.8mL, three ethanol amine, again with three chlorine methane points times washing mortar, Wash together into the graduated cylinder, and methylene chloride in dilute Release to 100mL, and put

31、up for the night. Filter man Brown bottle for storage. 10.16 the arsenic standard stock solution: weigh accurately in sulfuric acid 0.1320g dryer for drying or drying at 100 2H arsenic trioxide, and 5ml. Sodium hydroxide solution (200g/L), dissolved plus 25mL acid (6+94), move people 1000mL in the b

32、ottle, add new boiled cooled water diluted to scale, and store in a brown glass bottle. Arsenic per ml of this solution corresponds to 0.10mg. 10.17 arsenic standard solution: lessons 1.0mL arsenic standard stock solution, at 100mL. Volumetric flask, add 1mL sulfate (6+94).manipulator control mode a

33、nd programmable controllers introduction 2.1 Select discussion with manipulator control 2.1.1 classification of control relays and discrete electronic circuit can control old industrial equipment, but also more common. Mainly these two relatively cheap and you can meet the old-fashioned, simple (or

34、simple) industrial equipment. So he can see them now, however these two control modes (relay and discrete electronic circuits) are these fatal flaws: (1) cannot adapt to the complex logic control, (2) only for the current project, the lack of compatibility and (3) not reforming the system with equip

35、ment improvements. Spring for the development of Chinas modern industrial automation technology the substantial increase in the level of industrial automation, completed the perfect relay of the computer too much. In terms of controlling the computer showed his two great advantages: (1) each of the

36、hardware can be installed on one or more microprocessors; (2) the official designer of the software writing content control is all about. Now in several ways in the context of industrial automation can often be seen in three ways: (1) Programmable Logical Controller (referred to as IPC); (2) Distrib

37、uted Control System (DCS for short), and (3) the Programmable Logical Controller (PLC for short). 2.1.2 PLC and the IPC and DCS contrast contrast 1, each of the three technologies of origins and development requirements for fast data processing makes it invented the computer. The men brought in term

38、s of hardware there, using a high level of standardization, can use more compatibility tools, is a rich software resources, especially the need for immediacy in operational systems. So the computer can effectively control is used to control and meet its speed, on the virtual model, real-time and in

39、computational requirements. Distributed system started with a control system for industrial automatic instrument used to control, whereas now it is successfully developed into industrial control computer used as a central collection and distribution system and transition of distributed control syste

40、m in analogue handling, loop control, has begun to reflect the use of a huge advantage. Though distributed system has great advantages in loop regulation, but only as a means of continuous process control. Optimization of PLC is the corresponding relay needs was born, its main use in the work order

41、control, early primary is replaced relay this hulking system, focused on the switch controlling the running order of functions. Marked by the microprocessor in the early 1970 of the 20th century emerged, micro-electronics technology has developed rapidly, people soon microelectronics processing technology will be used in the Programmable Logical Controller (that is9