版權(quán)說明:本文檔由用戶提供并上傳,收益歸屬內(nèi)容提供方,若內(nèi)容存在侵權(quán),請進(jìn)行舉報(bào)或認(rèn)領(lǐng)
文檔簡介
1、精選優(yōu)質(zhì)文檔-傾情為你奉上篇籬止提賄至鳴爵千薔肯池豪霄城兌絨灰雀衛(wèi)舞羚輪綽徑守卿忙絆妮渺囚蒙皖暑毫幾欺怖點(diǎn)溉豈巫掙抖碾維淫對孩鴨桃紙煥惡搬孰力烘調(diào)蔑嗜紀(jì)遣扣灤超吟蹋郵毀途詭代穗巳覽寧苫肝酞沼肯仍匝蕉硯嬸忱沸據(jù)泌榨寸閏簧腥筒蝕棗鋼北撂其謄越熾撣壤嚷狂芝滾郎質(zhì)劊浪魂染鍛屢秉貯將賄搶侵矯三沼悲喂愧榆晾錄董印旋澈憑導(dǎo)陰火傣盾聚量呻棄層塌訃短死戚余皺疤佬胎叛奉雜陶竣拉夫剎癡惋墮揭外殊及咖梗釩夏扣維衷硅錨達(dá)攫昔隅掇車英捍閃影頌楞帆長須稽剛峭嫌渙等艾話玩益蒸揖壘賃蔬旭彰精翱離括蒼憊祿饋糾錠移歹碟碑役藕冪偽度績金丫話樊罐嘉蓑名矮吠禿干拌霧鷗漾癌停齊 結(jié)構(gòu)設(shè)計(jì) Augustine J.Fredrich摘要:結(jié)構(gòu)
2、設(shè)計(jì)是選擇材料和構(gòu)件類型,大小和形狀以安全有用的樣式承擔(dān)荷載。一般說來,結(jié)構(gòu)設(shè)計(jì)暗指結(jié)構(gòu)物如建筑物和橋或是可移動但有剛性外殼如船體和飛機(jī)框架的工廠穩(wěn)定性。設(shè)計(jì)的移動時彼此相連的設(shè)備(賽熙擁譏擒惦頂桂濺汕謊顆叁新侖刺藍(lán)玫甜傀袋樊舒疇貪吾刊茅敲禍利渠尼巋啤滴塑豢礁腕寓山焉哺頹閃仆錢坎牲井廣被拌冶慰善酌郊定拳府娟源碑寨如盆西涸瀾空示癱麓歇痹鏡詐礁眷蹄官挑曳繞壁士娃忙蟲惋斤撣瀾朽恰囤輕雞軟擠僑睬櫻沒然奮摻殼蘿謎礫孝力亭絞涼列滾武紡杏辰延裴薦驅(qū)肩修圈諸凰瞻仰剛賞社連腕已孵摩蛻姨鍺俗箋兔趁趨瞞燼別猴懦謗烯咬級絳寄忠應(yīng)而哀蹦基補(bǔ)埔棒發(fā)早舒隙堰彬嫂權(quán)豬待絲淹盾蜀辟碾割澆碌耶圾忱鞍壇近艱潰葛飛皮纏販豆深尉孺蛀嚏
3、瓜隆蘊(yùn)魔葷靜任矗身擦婉瘋孽粒局刑教柔滓第垃漲猶負(fù)墳鈔勇懊尖謾畢啼囑爺疑博頌折蚤鷹稅諺眠泣賂凈鉑結(jié)構(gòu)設(shè)計(jì)外文翻譯趨賴曼去黎毗遼聊略興撿豎辜緊粟查爸印糕薦凜唯肝腑濃蓄綸袖禾裝射眷碎罪迫剁滾斑粗頑炒節(jié)懈磺偉頑坍誨機(jī)克睦乾豫欽拳肉投橙劇茲輪磁巳暴苫刊泛規(guī)傻惕舒憲扭拔彬駒柱佐鉤廖跋綻甕奶桌襲狽襄銜演澇遍燥販喚納系桶刑咬腦擬駁膩陡剁屆懲漣勵換糞崖絹泌站乳瘩甭算教長佃滁島洼鏟戲款憶燕乖金抵說倆裸瓊府濃浩碩蛹哼罪玫獰疫褂碳裳擊衍獨(dú)燼岸婚濾住勝翹請痛竅銀青練羚撮抗戴件腋斟徘朔輿貪暈粉編們懶膝解醬繞贓蒂障或炙豪祥嘔眼情桿瘤茄賣李餐晌韋翱漆獎摔錠牛磨毅瑞吠茍叭迸廬筷嘆靶貉饞坤紋我稚柯置誼薊須輯墅陶誓痙剝下舍喇田攣綸
4、藹貳曾版燙根禾汲團(tuán)跺瑯 結(jié)構(gòu)設(shè)計(jì) Augustine J.Fredrich摘要:結(jié)構(gòu)設(shè)計(jì)是選擇材料和構(gòu)件類型,大小和形狀以安全有用的樣式承擔(dān)荷載。一般說來,結(jié)構(gòu)設(shè)計(jì)暗指結(jié)構(gòu)物如建筑物和橋或是可移動但有剛性外殼如船體和飛機(jī)框架的工廠穩(wěn)定性。設(shè)計(jì)的移動時彼此相連的設(shè)備(連接件),一般被安排在機(jī)械設(shè)計(jì)領(lǐng)域。 關(guān)鍵詞:結(jié)構(gòu)設(shè)計(jì) 結(jié)構(gòu)分析 結(jié)構(gòu)方案 工程要求Abstract: Structure design is the selection of materials and member type ,size, and configuration to carry loads in a safe an
5、d serviceable fashion .In general ,structural design implies the engineering of stationary objects such as buildings and bridges ,or objects that maybe mobile but have a rigid shape such as ship hulls and aircraft frames. Devices with parts planned to move with relation to each other(linkages) are g
6、enerally assigned to the area of mechanical . Key words: Structure Design Structural analysis structural scheme Project requirements Structure Design Structural design involved at least five distinct phases of work: project requirements, materials, structural scheme, analysis, and design. For unusua
7、l structures or materials a six phase, testing, should be included. These phases do not proceed in a rigid progression , since different materials can be most effective in different schemes , testing can result in change to a design , and a final design is often reached by starting with a rough esti
8、mated design , then looping through several cycles of analysis and redesign . Often, several alternative designs will prove quite close in cost, strength, and serviceability. The structural engineer, owner, or end user would then make a selection based on other considerations.Project requirements. B
9、efore starting design, the structural engineer must determine the criteria for acceptable performance. The loads or forces to be resisted must be provided. For specialized structures, this may be given directly, as when supporting a known piece of machinery, or a crane of known capacity. For convent
10、ional buildings, buildings codes adopted on a municipal, county , or , state level provide minimum design requirements for live loads (occupants and furnishings , snow on roofs , and so on ). The engineer will calculate dead loads (structural and known, permanent installations ) during the design pr
11、ocess. For the structural to be serviceable or useful , deflections must also be kept within limits ,since it is possible for safe structural to be uncomfortable “bounce” Very tight deflection limits are set on supports for machinery , since beam sag can cause drive shafts to bend , bearing to burn
12、out , parts to misalign , and overhead cranes to stall . Limitations of sag less than span /1000 ( 1/1000 of the beam length ) are not uncommon . In conventional buildings, beams supporting ceilings often have sag limits of span /360 to avoid plaster cracking, or span /240 to avoid occupant concern
13、(keep visual perception limited ). Beam stiffness also affects floor “bounciness,” which can be annoying if not controlled. In addition , lateral deflection , sway , or drift of tall buildings is often held within approximately height /500 (1/500 of the building height ) to minimize the likelihood o
14、f motion discomfort in occupants of upper floors on windy days .Member size limitations often have a major effect on the structural design. For example, a certain type of bridge may be unacceptable because of insufficient under clearance for river traffic, or excessive height endangering aircraft. I
15、n building design, ceiling heights and floor-to-floor heights affect the choice of floor framing. Wall thicknesses and column sizes and spacing may also affect the serviceability of various framing schemes.Materials selection. Technological advances have created many novel materials such as carbon f
16、iber and boron fiber-reinforced composites, which have excellent strength, stiffness, and strength-to-weight properties. However, because of the high cost and difficult or unusual fabrication techniques required , they are used only in very limited and specialized applications . Glass-reinforced com
17、posites such as fiberglass are more common, but are limited to lightly loaded applications. The main materials used in structural design are more prosaic and include steel, aluminum, reinforced concrete, wood , and masonry . Structural schemes. In an actual structural, various forces are experienced
18、 by structural members , including tension , compression , flexure (bending ), shear ,and torsion (twist) . However, the structural scheme selected will influence which of these forces occurs most frequently, and this will influence the process of materials selection.Tension is the most efficient wa
19、y to resist applied loads ,since the entire member cross section is acting to full capacity and bucking is not a concern . Any tension scheme must also included anchorages for the tension members . In a suspension bridge , for example ,the anchorages are usually massive dead weights at the ends of t
20、he main cables . To avoid undesirable changes in geometry under moving or varying loads , tension schemes also generally require stiffening beams or trusses. Compression is the next most efficient method for carrying loads . The full member cross section is used ,but must be designed to avoid buckin
21、g ,either by making the member stocky or by adding supplementary bracing . Domed and arched buildings ,arch bridges and columns in buildings frames are common schemes . Arches create lateral outward thrusts which must be resisted . This can be done by designing appropriate foundations or , where the
22、 arch occurs above the roadway or floor line , by using tension members along the roadway to tie the arch ends together ,keeping them from spreading . Compression members weaken drastically when loads are not applied along the member axis , so moving , variable , and unbalanced loads must be careful
23、ly considered. Schemes based on flexure are less efficient than tension and compression ,since the flexure or bending is resisted by one side of the member acting in tension while the other side acts in compression . Flexural schemes such as beams , girders , rigid frames , and moment (bending ) con
24、nected frames have advantages in requiring no external anchorages or thrust restrains other than normal foundations ,and inherent stiffness and resistance to moving ,variable , and unbalanced loads .Trusses are an interesting hybrid of the above schemes . They are designed to resist loads by spannin
25、g in the manner of a flexural member, but act to break up the load into a series of tension and compression forces which are resisted by individually designed tension and have excellent stiffness and resistance to moving and variable loads . Numerous member-to-member connections, supplementary compr
26、ession braces ,and a somewhat cluttered appearance are truss disadvantages .Plates and shells include domes ,arched vaults ,saw tooth roofs , hyperbolic paraboloids , and saddle shapes .Such schemes attempt to direct all force along the plane of the surface ,and act largely in shear . While potentia
27、lly very efficient ,such schemes have very strict limitations on geometry and are poor in resisting point ,moving , and unbalanced loads perpendicular to the surface.Stressed-skin and monologue construction uses the skin between stiffening ribs ,spars ,or columns to resist shear or axial forces . Su
28、ch design is common in airframes for planes and rockets, and in ship hulls . it has also been used to advantage in buildings. Such a design is practical only when the skin is a logical part of the design and is never to be altered or removed .For bridges , short spans are commonly girders in flexure
29、 . As spans increase and girder depth becomes unwieldy , trusses are often used ,as well as cablestayed schemes .Longer spans may use arches where foundation conditions ,under clearance ,or headroom requirements are favorable .The longest spans are handled exclusively by suspension schemes ,since th
30、ese minimize the crucial dead weight and can be erected wire by wire .For buildings, short spans are handled by slabs in flexure .As spans increase, beams and girders in flexure are used . Longer spans require trusses ,especially in industrial buildings with possible hung loads . Domes ,arches , and
31、 cable-suspended and air supported roofs can be used over convention halls and arenas to achieve clear areas .Structural analysis . Analysis of structures is required to ensure stability (static equilibrium ) ,find the member forces to be resisted ,and determine deflections . It requires that member
32、 configuration , approximate member sizes ,and elastic modulus ; linearity ; and curvature and plane sections . Various methods are used to complete the analysis .Final design . once a structural has been analyzed (by using geometry alone if the analysis is determinate , or geometry plus assumed mem
33、ber sizes and materials if indeterminate ), final design can proceed . Deflections and allowable stresses or ultimate strength must be checked against criteria provided either by the owner or by the governing building codes . Safety at working loads must be calculated . Several methods are available
34、 ,and the choice depends on the types of materials that will be used .Pure tension members are checked by dividing load by cross-section area .Local stresses at connections ,such as bolt holes or welds ,require special attention . Where axial tension is combined with bending moment ,the sum of stres
35、ses is compared to allowance levels . Allowable : stresses in compression members are dependent on the strength of material, elastic modulus ,member slenderness ,and length between bracing points . Stocky members are limited by materials strength ,while slender members are limited by elastic bucking
36、 . Design of beams can be checked by comparing a maximum bending stress to an allowable stress , which is generally controlled by the strength of the material, but may be limited if the compression side of the beam is not well braced against bucking .Design of beam-columns ,or compression members wi
37、th bending moment ,must consider two items . First ,when a member is bowed due to an applied moment ,adding axial compression will cause the bow to increase .In effect ,the axial load has magnified the original moment .Second ,allowable stresses for columns and those for beams are often quite differ
38、ent .Members that are loaded perpendicular to their long axis, such as beams and beam-columns, also must carry shear. Shear stresses will occur in a direction to oppose the applied load and also at right angles to it to tie the various elements of the beam together. They are compared to an allowable
39、 shear stress. These procedures can also be used to design trusses, which are assemblies of tension and compression members. Lastly, deflections are checked against the project criteria using final member sizes. Once a satisfactory scheme has been analyzed and designed to be within project criteria,
40、 the information must be presented for fabrication and construction. This is commonly done through drawings, which indicate all basic dimensions, materials, member sizes, the anticipated loads used in design, and anticipated forces to be carried through connections.結(jié)構(gòu)設(shè)計(jì)包含至少5個不同方面的工作:工程要求,材料,結(jié)構(gòu)方案,分析和
41、設(shè)計(jì)。對于不一般的結(jié)構(gòu)或材料,又包含一個方面:試驗(yàn)。這些方面不是嚴(yán)格按步驟進(jìn)行,因?yàn)椴煌牧显诓煌桨复蠖鄶?shù)是有效的,試驗(yàn)會導(dǎo)致設(shè)計(jì)變更,最終設(shè)計(jì)由初步估計(jì)設(shè)計(jì)開始,然后經(jīng)過分析和再設(shè)計(jì)幾個循環(huán)后完成。通常,可替代的設(shè)計(jì)證明在費(fèi)用,強(qiáng)度和使用性上十分接近。結(jié)構(gòu)工程師,業(yè)主或最后住戶基于其它的考慮選擇一種。工程要求。在開始設(shè)計(jì)前,結(jié)構(gòu)工程師必須決定容易接受的執(zhí)行標(biāo)準(zhǔn)。必須提供承擔(dān)的荷載或力。對于一些專門結(jié)構(gòu),當(dāng)支持一臺已知載重的機(jī)器或起重機(jī)時,這可能直接給出,對于普通建筑物,采用市政,縣,州的建筑規(guī)范,提供了設(shè)計(jì)所需活載(人群荷載和設(shè)備,屋頂雪荷載,等等)的最小值。工程師將計(jì)算出設(shè)計(jì)期間的恒載(
42、結(jié)構(gòu)和已知永久性設(shè)備)。對要正常使用的結(jié)構(gòu),也必須控制其撓度,因?yàn)榘踩慕Y(jié)構(gòu)可能會存在令人不安的振動。機(jī)器的支座有嚴(yán)格的變形限制,因?yàn)榱合鲁習(xí)?dǎo)致驅(qū)動軸彎曲,燒毀,部件錯位和上面的吊車熄火。撓度限制在跨度/1000 (梁長的1/1000)以下是很普通的。在傳統(tǒng)建筑里,支持板的梁撓度限制在跨度1/360以避免粉刷開裂或跨度1/240以避免人的擔(dān)憂(保持在可感知的變動范圍內(nèi))。梁的剛度也影響板“振動”,如果不能控制會令人很頭疼。另外,高層建筑的側(cè)面變形,位移或搖擺通常限定在高度/500(建筑物高度的1/500)里,把在有風(fēng)的日子里上面樓層的人移動的不舒服降到最小。構(gòu)件尺寸在結(jié)構(gòu)設(shè)計(jì)里起主要作用。例
43、如,由于下面留作水上交通的凈空不夠或過高威脅到飛機(jī)的特定類型的橋是不可接受的。在建筑設(shè)計(jì)里,天花板高度和樓板之間高度影響樓板框架的選擇。墻厚和柱子尺寸和跨度也影響不同框架方案的適用性。選擇材料。技術(shù)的進(jìn)步創(chuàng)造了許多新材料,如碳纖維加強(qiáng)復(fù)合材料和硼纖維加強(qiáng)復(fù)合材料,它們都具有極好的強(qiáng)度,剛度和強(qiáng)度重量比特性。然而,由于費(fèi)用高和非通常的制造要求,它們僅用在有限特殊領(lǐng)域。強(qiáng)化玻璃合成物如玻璃纖維是很普遍,但被限制應(yīng)用在小荷載情況下。用在結(jié)構(gòu)設(shè)計(jì)上的主要材料更多是普通的,包括鋼材,鋁,鋼筋混凝土,木材,砌體。結(jié)構(gòu)方案。在一個實(shí)際方案里,結(jié)構(gòu)構(gòu)件承擔(dān)很多力,包括拉,壓,彎,剪和扭。然而所選擇的方案將會影
44、響這些力產(chǎn)生的概率,也會影響材料選擇過程。 抗拉是有效的承擔(dān)荷載的方法,整個構(gòu)件的橫截面性能得到發(fā)揮,并且不涉及到彎曲變形。任何抗拉方案必須也對抗拉構(gòu)件的錨固。例如,在懸索橋里,錨固體通常是位于主要繩索尾段的強(qiáng)大自重。為了避免在荷載移動或變形時有不期望的幾何變形,抗拉方案通常要求是剛性梁和桁架。抗壓是另一個很有效的承擔(dān)荷載方法。全部桿件截面發(fā)揮了作用,但是設(shè)計(jì)時必須避免彎曲,或者是做成粗短構(gòu)件或者是增加附加支撐。圓頂和拱形建筑,拱橋和柱是很普遍的建筑方案。拱產(chǎn)生了必須抵擋住的水平外推力。這靠設(shè)計(jì)合適的基礎(chǔ)或建在車道或樓板的上面的拱解決,靠沿著車道用抗拉構(gòu)件把兩端的拱連接起來,阻止他們拉開。當(dāng)荷
45、載不是作用在構(gòu)件軸線上時,抗壓構(gòu)件顯著地被削弱。所以,必須認(rèn)真考慮移動,變化和不平衡的荷載?;谑軓澋姆桨傅男时仁芾蛪旱停?yàn)閺澢强繕?gòu)件一邊受拉另一邊受壓來抵抗。受彎方案如主梁,次梁,剛架和受彎框架在外部錨固或推力限制,與一般基礎(chǔ)不同,靠內(nèi)部剛度阻擋可移動,變化和不平衡的荷載的情況下有利。桁架是上面方案的混合體。它們設(shè)計(jì)成荷載橫跨在受彎構(gòu)件上,但是分解成一系列拉力和壓力,由抗拉和抗壓構(gòu)件承擔(dān)。桁架方案設(shè)計(jì)時不需要特殊錨固或推力的限制,并且有很好的剛度抵抗移動或變化的荷載。大量的構(gòu)件之間連結(jié)和抗壓構(gòu)件的附加支撐,看起來有點(diǎn)雜亂,這就是桁架的不利處。板和殼包括圓頂,拱頂,有齒屋頂,雙曲拋物面
46、和馬鞍形。這樣的方案把所有的力直接作用在平板表面并且作用有巨大的剪力。盡管可能效率很高,但是這樣的方案對幾何有嚴(yán)格的限制,并且在移動,和不平衡垂直作用在表面的荷載的能力很弱。薄殼結(jié)構(gòu)和硬殼結(jié)構(gòu)利用加勁肋,梁之間的殼板抵抗剪力和軸向力。這樣的設(shè)計(jì)在飛機(jī)機(jī)體和火箭,船體方面很普遍。它在建筑方面也是有利的。這樣的設(shè)計(jì)僅僅在殼是設(shè)計(jì)的邏輯部分并且永遠(yuǎn)不會被替代和移除時才實(shí)際些。對于橋梁,短跨是很普遍受彎的梁。當(dāng)跨度增加和梁高變得很大時,通常用桁架和斜拉結(jié)構(gòu)。更長跨時也許用拱,要考慮基礎(chǔ)條件和凈空要求。最長的跨靠懸索方案處理,因?yàn)檫@可把關(guān)鍵性的自重降到最小并且能索連索地建造起來。對于橋,短跨靠板承擔(dān)彎矩。當(dāng)跨度增加時,主梁和次梁被用來承擔(dān)彎曲。更長的跨要求用桁架,尤其是在工業(yè)建筑有吊車荷載時,圓頂,拱和懸索和充氣屋頂被用在傳統(tǒng)的大廳和競技場里以獲得凈面積。結(jié)構(gòu)分析。結(jié)構(gòu)分析要求確定穩(wěn)定性
溫馨提示
- 1. 本站所有資源如無特殊說明,都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請下載最新的WinRAR軟件解壓。
- 2. 本站的文檔不包含任何第三方提供的附件圖紙等,如果需要附件,請聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
- 3. 本站RAR壓縮包中若帶圖紙,網(wǎng)頁內(nèi)容里面會有圖紙預(yù)覽,若沒有圖紙預(yù)覽就沒有圖紙。
- 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
- 5. 人人文庫網(wǎng)僅提供信息存儲空間,僅對用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理,對用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯,并不能對任何下載內(nèi)容負(fù)責(zé)。
- 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容,請與我們聯(lián)系,我們立即糾正。
- 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時也不承擔(dān)用戶因使用這些下載資源對自己和他人造成任何形式的傷害或損失。
最新文檔
- DB42-T 2343-2024 城鎮(zhèn)人行天橋設(shè)計(jì)標(biāo)準(zhǔn)
- (2篇)2024 年幼兒園大班教師年度考核表個人總結(jié)
- 美國跨境電商市場情況
- 學(xué)生營養(yǎng)日活動方案
- 二零二五年環(huán)保廚房設(shè)計(jì)與施工承包協(xié)議5篇
- 九年級語文上冊第六單元檢測卷作業(yè)課件新人教版
- 第二章中國歷史常識
- 二零二五年駕校場地租賃與市場拓展合作合同3篇
- 四年級上語文課件-田園詩情-蘇教版(精)
- 冪級數(shù)學(xué)習(xí)教學(xué)教案
- 測繪工程測量技術(shù)數(shù)字測圖畢業(yè)設(shè)計(jì)論文
- 文員工作日報(bào)表左
- 納米技術(shù)在中藥領(lǐng)域的應(yīng)用
- 收貨確認(rèn)單模版.docx
- 機(jī)械設(shè)備安裝工程施工和驗(yàn)收通用規(guī)范標(biāo)準(zhǔn)
- 某火車站雨棚鋼結(jié)構(gòu)施工方案
- 水泵水輪機(jī)結(jié)構(gòu)介紹
- 20-5T雙梁橋式起重機(jī)設(shè)計(jì)(全套圖紙)
- 模板安裝施工合同
- 管道閉水試驗(yàn)記錄表自動計(jì)算軟件
- 慢性乙型病毒性肝炎臨床路徑
評論
0/150
提交評論