衢州學(xué)院本科畢業(yè)設(shè)計(jì)(論文)外文翻譯

1、衢州學(xué)院本科畢業(yè)設(shè)計(jì)(論文)外文翻譯譯文：建筑材料建筑材料必須具有對(duì)結(jié)構(gòu)有用的某些物理性質(zhì)。 首先，建筑材料必須能夠承受荷載或重量，而不會(huì)永久改變其原有的形狀。當(dāng)荷載施加到結(jié)構(gòu)單元上時(shí)，材料將發(fā)生變形，也就是說，線材將伸長或梁將會(huì)彎曲。然后卸載后，線材和梁將恢復(fù)原狀。材料的這種性質(zhì)稱為彈性。如果某種材料是非彈性的，在卸荷后結(jié)構(gòu)將殘留變形，重復(fù)加荷和卸荷，結(jié)構(gòu)的變形將持續(xù)增加，直至最后結(jié)構(gòu)失效。用于建筑結(jié)構(gòu)的所有材料，諸如磚石、木材、鋼材、鋁材、鋼筋混凝土的塑料等，在一定范圍的荷載作用下均表現(xiàn)出彈性如果荷載增加超過這個(gè)范圍，材料將表現(xiàn)出兩種類型的性質(zhì)：脆性和塑性。若為前者，材料將會(huì)突然斷裂；若為

2、后者，材料在達(dá)到某一荷載（屈服強(qiáng)度）開始塑性流動(dòng)，最后破壞。例如，鋼材表現(xiàn)出塑性，石材則是脆性的。材料的最終強(qiáng)度用材料破壞時(shí)的極限應(yīng)力來表示。建筑材料第二個(gè)重要性質(zhì)是剛度。這一性質(zhì)用彈性模量來表示，彈性模量是應(yīng)力（單位面積上的力）和應(yīng)變（單位長度上的變形）的比值。因而彈性模量是衡量材料在荷載作用下抵抗變形能力的指標(biāo)。對(duì)于相同荷載作用下相同面積的兩種材料，彈性模量越高者變形越小。結(jié)構(gòu)鋼材，其彈性模量是3*108LB/IN2，或21000000kg/cm2，是鋁材剛度的3倍、混凝土剛度的10倍、木材剛度的15倍。砌體，砌體包含天然材料，如石材、人造產(chǎn)品如混凝土砌塊。砌體出現(xiàn)在遠(yuǎn)古時(shí)期。在古巴比輪城

3、市，泥土磚用于建造非宗教性建筑物，而石材被廣泛用語尼羅河流域雄偉的寺廟。高及481ft(147m)的埃及大金字塔是最為壯觀的石工材料。最初，砌塊的疊砌是不用膠粘劑的，但所有現(xiàn)代土磚或頁巖磚以及混凝土砌塊。砌體材料基本上屬于受壓材料，不能承受張拉力，亦即拉力。砌體的極限抗壓強(qiáng)度取決于砌體和砂漿。極限強(qiáng)度在1000到4000lb/in2(70280 kg/cm2)之間變化，其值取決于所有塊體和砂漿的具體結(jié)合。木材，木材是一種最古老的建筑材料，是少數(shù)具有抗拉性能的天然材料之一。全世界已經(jīng)發(fā)現(xiàn)的木材種類有數(shù)百種，每一類都表現(xiàn)出不同的物理特性。只有少數(shù)木材在建筑中被用做結(jié)構(gòu)構(gòu)件。例如，在美國，600多中

4、木材中僅有20種被用于結(jié)構(gòu)。這些木材通常是一些針葉樹或軟木材，主要因?yàn)檫@兩種木材資源豐富以及易于成型。在美國建筑中較為普遍使用的木材樹種是花期松、南木松、云杉和紅木。這些木材的極限抗拉強(qiáng)度變化范圍為50008000 lb/in2（350560 kg/cm2）。硬木材主要用于細(xì)木工或用于鋪地板之類的室內(nèi)裝修。由于木材本身有細(xì)胞狀結(jié)構(gòu)，其順紋強(qiáng)度要大于其橫紋強(qiáng)度，木材順紋的抗拉強(qiáng)度和抗壓強(qiáng)度尤其高，并且有很好的抗彎強(qiáng)度。這些性質(zhì)使得木材成為建筑結(jié)構(gòu)中柱和梁的理想材料。但是，由于桁架桿件中抗拉強(qiáng)度取決與各種桿件的連接，所以木材不能有效地在桁架中用作受拉構(gòu)件。盡管為了利用木材的抗拉強(qiáng)度制造出許多金屬節(jié)

5、點(diǎn)，但很難設(shè)計(jì)出與順紋剪切強(qiáng)度或抗裂強(qiáng)度關(guān)系不大的接頭。鋼材，鋼材是一種優(yōu)異的結(jié)構(gòu)材料。與其他材料相比，鋼材有高強(qiáng)度質(zhì)量比（單位質(zhì)量的強(qiáng)度），即在相同體積條件下其質(zhì)量是木材的10倍以上。鋼材具有較高的彈性模量，這就使得鋼筋在荷載作用下變形較小。鋼材可被軋制成各種不同的結(jié)構(gòu)形狀，如工字型梁、鋼板和壓型鋼板，還能被鑄造成復(fù)雜形狀，也能用以生產(chǎn)出鋼絲和鋼絞線，用作懸索橋和旋索屋面的鋼纜，電梯升運(yùn)機(jī)纜索，或用作預(yù)應(yīng)力混凝土的鋼絲絞線。鋼制構(gòu)件可以用多種方法進(jìn)行連接，如螺栓連接、鉚接或焊接。碳素鋼易遭氧化導(dǎo)致腐蝕，必須防止其與大氣的接觸，可采用在其上刷防銹或?qū)⑵渎袢牖炷恋霓k法。當(dāng)溫度高于700F（37

6、1）時(shí)，鋼材將迅速喪失其強(qiáng)度，因而必須在其外包裹上防火材料（通常為混凝土）對(duì)其加以保護(hù)。合金元素如硅或錳的加入使鋼材強(qiáng)度變得更高，其抗拉強(qiáng)度可達(dá)250000 LB/IN2（17500kg/cm2）。當(dāng)結(jié)構(gòu)構(gòu)件的尺寸變得重要時(shí)，如摩天大樓的柱子，就要使用這類合金鋼。鋁材，當(dāng)輕質(zhì)、強(qiáng)度和防腐蝕能力成為建筑考慮的重要因素時(shí)，鋁材作為一種建筑材料就顯得特別有用。因?yàn)榧冧X極軟，易延展，必須在其中加入錳、硅、鋅和銅這些合金元素，使其獲得結(jié)構(gòu)所要求的強(qiáng)度。建筑用鋁合金表現(xiàn)出彈性，其彈性模量是鋼材的1/3，因而在相同荷載作用下，其變形為鋼材的3倍。鋁合金的密度為鋼材的1/3，因而在相似強(qiáng)度條件下，鋁合金構(gòu)件比

7、鋼材構(gòu)件輕。鋁合金的極限抗拉強(qiáng)度范圍在20006000lb/in2(14004200kg/cm2)。鋁材能被加工成各種狀態(tài)，可以被擠壓成工字型梁，拔成線材和桿件，輥壓成鋁箔和板材。鋁構(gòu)件可以像鋼材一樣采用鉚接、螺釘連接以及（較少地）焊接等方式進(jìn)行連接。鋁除了用作建筑和預(yù)制房屋的框架構(gòu)件以外，還被廣泛地用作窗框，以及幕墻建筑物的幕墻材料?；炷?，混凝土是水、砂石子和波特蘭水泥和混合物。碎石、人造輕骨料、貝殼經(jīng)常被用以代替天然石料。波特蘭水泥，是將由鈣質(zhì)材料和黏土質(zhì)材料形成的混合物在窯中進(jìn)行煅燒然后進(jìn)行粉磨而形成的?；炷翉?qiáng)度即源于磨細(xì)的水泥與水混合時(shí)經(jīng)水化而硬化的過程。在理想的混合狀態(tài)下，混凝土

8、由占其體積大約3/4的砂、石子和占其體積1/4的水泥漿組成?；炷恋奈锢硖匦詫?duì)其組成成分變化是極其敏感的，所以為了獲得混凝土在強(qiáng)度和收縮等方面特定的效果，必須對(duì)這些組成材料的配料進(jìn)行特定的設(shè)計(jì)。當(dāng)往模具或模板中澆注時(shí)，混凝土中含有大量并非用于水化而是要蒸發(fā)掉的水。混凝土硬化時(shí)，經(jīng)過一段時(shí)間將蒸發(fā)掉多余的水而產(chǎn)生收縮，這種收縮通常將導(dǎo)致細(xì)裂縫的發(fā)展。為了將這些裂縫減至最少，混凝土硬化時(shí)必須保持潮濕狀態(tài)至少在5天以上。以為混凝土的水化過程能持續(xù)進(jìn)行多年，故其強(qiáng)度能夠持續(xù)增長。事實(shí)上，常把混凝土28天的強(qiáng)度視為標(biāo)準(zhǔn)強(qiáng)度?；炷猎诤奢d作用下會(huì)發(fā)生彈性變形。盡管混凝土的彈性模量是鋼材的1/10，但由于其

9、強(qiáng)度也大約是鋼材的1/10，所以它們有相似的變形?；炷林饕米骺估牧?，其抗拉強(qiáng)度可不予考慮。鋼筋混凝土，鋼筋混凝土中配有鋼筋，用以承受混凝土構(gòu)件中的拉力。這些鋼筋的直徑范圍在0.25in（0.64cm）2.25in(5.7cm)，其表面帶肋，以保證與混凝土的黏結(jié)。盡管鋼筋混凝土在很多國家得到發(fā)展，但其發(fā)展一般歸功于約瑟夫，一位法國園丁，他在1868年曾使用鋼筋網(wǎng)片來加強(qiáng)混凝土管，因?yàn)闇囟茸兓瘯r(shí)，鋼材與混凝土脹縮系數(shù)相同，所以這種做法是可行的，如若不然，鋼材與混凝土的黏結(jié)會(huì)因溫度的變化導(dǎo)致兩者變形不一致而破壞。鋼筋混凝土可以澆注成各種形狀，如梁、柱、板和拱，因而適用于特殊形態(tài)的建筑物。鋼筋混

10、凝土的極限強(qiáng)度抗拉強(qiáng)度可能會(huì)超過10000lb/in2(700kg/cm2)，盡管產(chǎn)生的大部分商品混凝土的強(qiáng)度低于6000lb/in2(420kg/cm2)。塑料，塑料因其多樣性、強(qiáng)度、耐久性和輕質(zhì)而迅速成為一種重要的建筑材料。塑料是一種合成材料或樹脂，能按要求塑造成各種形狀，采用有機(jī)物作膠粘劑。有機(jī)的塑料分為兩大類：熱固性塑料和熱塑性塑料。熱固性塑料受熱時(shí)發(fā)生化學(xué)變化而變硬，一旦成型，著類塑料不能在塑成型。熱塑性塑料在高溫時(shí)仍保持柔軟，冷卻后才變硬，這類塑料通常不能用作建筑材料。原文：Build materialsMaterials for building must have certai

11、n physical properties to be structurally useful. primarily ,they must be able to carry a load , or weight , without changing shape permanently . when a load is applied to a structure member , it will deform ; that is , a wire will stretch or a beam will bend . however , when the load is removed ,the

12、 wire and the beam come back to the original position ,this material property is called elasticity ,if a material were not elastic and a deformation were present in structure after removal of the load , repeated loading and unloading eventually would increase the deformation to the point where the s

13、tructure would become useless . all material used in architectural structure , such as stone and brick , wood , steel , aluminum , reinforced concrete ,and plastics , behave elastically within a certain defined range of loading . if the loading is increased above the range , two type of behavior can

14、 occur ; brittle and plastic . in the former , the , material will break suddenly . in the latter , the material begins to flow at a certain load (yield strength) , ultimately leading to fracture . as example , steel exhibits plastic behavior , and stone is brittle . the ultimate strength of a mater

15、ial is measured by the stress at which failure (fracture) occurs .A second important property of a building is its stiffness . this property is defined by the elastic modulus ,which is the ratio of the stress (force per unit area) , to the strain (deformation per unit length) . the elastic modulus ,

16、 therefore , is a measure of the resistance of a material to deformation under load . for two material to equal area under the same load , the one with the higher elastic modulus has the smaller deformation .structural steel , which has an elastic modulus of 30 million pounds per square inch (psi) ,

17、 or 2100000 kilograms per square centimeter , is 3 time as stiff as aluminum , 10 times as stiff as concrete , and 15 times as stiff as wood .Masonry consists of natural materials , such as stone , or manufactured products , such as brick and concrete block . masonry has been used since ancient time

18、s ; mud brick were used in the city of Babylon for secular buildings , and stone was used for the great temples of the Nile Valley . the great pyramid in Egypt . standing 481 feet (147 meters) high , is the most spectacular masonry construction . masonry units originally were stacked without using a

19、ny bonding agent , but all modern construction uses a cement mortar as a bonding material . modern structural materials include stone , brick of burnt clay or slate , and concrete blocks .Masonry is essentially a compressive material ; it cannot withstand a tensile force , that is , a pull. The ulti

20、mate compressive strength of bonded masonry depends on the strength of the masonry until and the mortar. The ultimate strength will vary form 1000 to 4000 psi (70 to 280 kg/sq cm), depending on the particular combination of masonry unit and mortar used.Timber is one of the earliest construction mate

21、rials and one of the few natural materials with good tensile properties. Hundreds of different species of wood are found throughout the world , and each species exhibits different physical characteristics. Only a few species are used structurally as framing members in building construction. In the u

22、ntied states, for instance, out of more than 600 species of wood, only 20 species are used structurally. These are generally the conifers, or softwoods, both because of their abundance and because of the ease with which their wood can be shaped. The species of their more commonly used in the untied

23、states for construction are Douglas fir, southern pine, spruce, and redwood. The ultimate tensile strength of these species varies form 5000 to 8000 psi (350 to 560 kg/sq cm). Hardwood are used primarily for cabinetwork and for interior finishes such as floors.Because of the cellular of wood, it is

24、stronger along the grain than across the grain. Wood id particularly strong in tension and compression parallel to the grain. And it has great bending strength. These properties make it ideally suited for columns and beams in structures. Wood is not effectively used as a tensile member in a truss, h

25、owever, because the tensile strength of a truss member depends upon connections between members. It is difficult to devise connections which do not depend on the shear or tearing strength along the grain, although numerous metal connectors have been produced to utilize the tensile strength of timber

26、s.Steel is an outstanding structural material. It has a high strength on a pound-for-pound basis when compared to other materials, even thought its volume-for-volume weight is more than times that of wood. It has a high elastic modulus, which results in small deformations under load. It can be forme

27、d by rolling into various structural shapes such as I-beams, plates, and sheets; it also can be cast into complex shapes; and it is also produced in the form of wire strands and ropes for use as cables in suspension bridges and suspended roofs, as elevator rope, and as wire for pestering concrete. S

28、teel element can be joined together by various means, such as bolting, riveting, or welding. Carbon steels are subject to corrosion through oxidation and must be protected form contact with the atmosphere by painting them or embedding them in concrete. Above temperatures of about 700F(371), steel ra

29、pidly loses its strength, and therefore it must be covered in a jacket of a fireproof material(usually concrete) to increase its fire resistance.The addition of alloying elements, such as silicon or manganese, results in higher strength steels with tensile strengths up to 250000 psi(17500kg/sq cm).

30、These steels are used where the size of a structural member become critical, as in the case of columns in a skyscraper. Aluminum is especially useful as a building when lightweight, strength, and corrosion are all important factors. Because pure aluminum is extremely soft and ductile, alloying eleme

31、nts, such as magnesium, silicon, zinc, and copper, must be added to it to impart the strength required for structural use. Structural aluminum alloys behave elastically. They have an elastic modulus one third as great as steel and therefore deform there times as much as steel under the same load. Th

32、e unit weight of an aluminum alloy is one third that of steel, and therefore an aluminum member will be lighter than a steel member of comparable strength. The ultimate tensile strength of aluminum alloys ranges form 20000 to 60000 psi (1400 to 4200kg/sq cm).Aluminum can be formed into a variety of

33、shapes; it can be extruded to form I-beams, drawn to form wire and rode, and rolled to form foil and plates. Aluminum members can be put together in the same way as steel by riveting, bolting, and (to a lesser extent) by welding. Apart form its use for framing members in buildings and prefabricated

34、housing, aluminum also finds extensive use for window frames and for skin of the building in curtain-wall construction.Concrete is a mixture of water, sand and gravel, and Portland cement. Crushed stone, manufactured lightweight stone, and seashells are often use in lieu of natural gravel. Portland

35、cement, which is a mixture of materials containing calcium and clay, is heated in a kiln and then pulverized. Concrete derives its strength form the fact that pulverized Portland cement, when mixed with water, hardens by a process called hydration. In an ideal mixture, concrete consists of about thr

36、ee fourths sand gravel (aggregate) by volume and one cement paste. The physical properties of concrete are highly sensitive to variations in the mixture of the components, so a particular combination of these ingredients must be custom-designed to achieve specified results in terms of strength or sh

37、rinkage. When concrete is poured into a mold or form, it contains free water, not required for hydration, which evaporate. As the concrete hardens, it releases this excess water over a period of time and shrinks. As a result of this shrinkage, fine cracks often develop. In order to minimize these sh

38、rinkage cracks, concrete must be hardened by keeping it moist for at least 5 days. The strength of concrete in time because the hydration process continues for years; as a practical matter, the strength at 28 days is considered standard.Concrete deform under load in an elastic manner. Although its e

39、lastic modulus is one tenth that of steel, similar deformations will result since its also about one tenth that of steel. Concrete is basically a compressive material and has negligible tensile strength.Reinforced concrete, Reinforced concrete has steel bars that are placed in a concrete member to c

40、arry tensile force. These Reinforced bars, which range in diameter form 0.25 inch(0.64cm) to 2.25 inches (5.7cm), have wrinkles on the surfaces to ensure a bond with the concrete. Although reinforced concrete was developed in many countries, its discovery usually is attributed to Joseph Monnier, a French gardener, who used a w