电大钢结构期末复习测试D及参考答案.docx

电大钢结构期末复习测试D及参考答案 钢结构模拟测试（D） 一、单项选择题（将每题正确答案的序号填入括号内，每小题2分，共计30分） 1下列钢结构计算所取荷载设计值和标准值，（ ）组符合钢结构设计规范。 A计算结构或构件的强度、稳定性以及连接的强度时，应采纳荷载标准值 B计算结构或构件的强度、稳定性以及连接的强度时，应采纳荷载设计值 C计算疲惫和正常运用极限状态时，应采纳荷载标准值 D计算疲惫和正常运用极限状态时，应采纳荷载设计值 2钢材的伸长率是反映材料（ ）的性能指标。A承载实力 B反抗冲击荷载实力 C弹性变形实力 D塑性变形实力 3以下关于应力集中的说法中正确的是（ ）。A 应力集中降低了钢材的屈服点 B应力集中产生同号应力场，使塑性变形受到限制 C应力集中产生异号应力场，使钢材变脆 D应力集中可以提高构件的疲惫强度 4钢材经验了应变硬化（应变强化）之后（ ）。A强度提高 B塑性提高 C冷弯性能提高 D可焊性提高 5钢材牌号Q235、Q345、Q390、Q420是依据材料（ ）命名的。 A屈服点 B设计强度 C抗拉强度 D含碳量 6承受轴心力作用的高强度螺栓摩擦型受剪切连接中，其净截面强度验算公式，其中与轴心拉杆所受的力相比，（ ）。 A B C D不定 7高强度螺栓摩擦型连接受剪破坏时，作用剪力超过了（ ）作为承载实力极限状态。 A螺栓的抗拉强度 B连接板件间的摩擦力 C连接板件的毛截面强度 D连接板件的孔壁承压强度 8部分焊透的对接焊缝的计算应按（ ）计算。 A 对接焊缝 B 斜焊缝 C 断续焊缝 D 角焊缝 9焊接工字形截面梁腹板设置加劲肋的目的是（ ）。 A提高梁的抗弯强度 B提高梁的抗剪强度 C提高梁的整体稳定性 D提高梁的局部稳定性 10一个承受剪力作用的一般螺栓在抗剪连接中的承载力是（ ）。A栓杆的抗剪承载力 B被连接构件（板）的承压承载力 CA、B中的较大值 DA、B中的较小值 11计算格构式轴心受压柱整体稳定时，用换算长细比代替，这是考虑（ ）。 A格构柱弯曲变形的影响 B格构柱剪切变形的影响 C缀材弯曲变形的影响 D缀材剪切变形的影响 12轴心受压构件柱脚底板的面积主要取决于（ ）。 A底板的抗弯刚度 B柱子的截面积 C基础材料的强度等级 D底板的厚度 13工字形截面梁受压翼缘宽厚比限值为，式中为（ ）。A翼缘板外伸宽度 B翼缘板全部宽度 C翼缘板全部宽度的1/3 D翼缘板的有效宽 14在焊接组合梁的设计中，腹板厚度应（ ）。 A 越薄越好 B 越厚越好 C 厚薄相当 D 厚薄无所谓 15计算格构式压弯构件的缀材时，剪力应取（ ）。 A构件实际剪力设计值 B由公式计算的剪力 C 构件实际剪力设计值或由公式计算的剪力两者中较大值 D由公式计算的剪力 二、推断题（正确的划“ ”，错误的划“× ”每小题2分，共计30分） 1在结构设计中，失效概率越大，牢靠指标越小，结构牢靠性越差。（ ） 2高温时，硫使钢变脆，称之冷脆；低温时，磷使钢变脆，称之冷脆热脆。( ) 3按脱氧方法，钢分为沸腾钢、半冷静钢、冷静钢和特别冷静钢，其中沸腾钢脱氧最差。( ) 钢材越厚压缩比越小，因此厚度大的钢材不但强度较小，而且塑性、冲击韧性和焊接性能也较差。( ) 5焊缝按施焊位置分为平焊、横焊、立焊及仰焊，其中平焊的操作条件最差，焊缝质量不易保证。( ) 6钢结构设计规范规定角焊缝中的最小焊角尺寸，其中t为较薄焊件的厚度。( ) 7构件上存在焊接残余应力会降低结构的刚度。( ) 8螺栓排列分为并列和错列两种形式，其中并列可以减小栓孔对截面的减弱，但螺栓排列松散，连接板尺寸较大。( ) 9在静荷载作用下，焊接残余应力不影响结构的静力强度。( ) 10轴心受压构件板件过薄，在压力作用下，板件离开平面位置发生凸曲现象，称为构件丢失整体稳定。( ) 11构件的长细比是计算长度与回转半径之比。( ) 12梁的抗剪强度不满意设计要求时，最有效的方法是增大腹板的高度。( ) 13工字形截面简支梁，当受压翼缘侧向支承点间距离越小时，则梁的整体稳定就越好。( ) 14偏心受压柱刚接柱脚只传递轴心压力和剪力，铰接柱脚除传递轴心压力和剪力外，还要传递弯矩。( ) 15进行拉弯和压弯构件设计时，压弯构件仅须要计算强度和刚度，拉弯构件则须要计算强度、局部稳定、整体稳定、刚度。( ) 三、简答题（每小题8分，共计24分） 1什么是疲惫断裂？影响钢材疲惫强度的因素有哪些？ 2为何要规定螺栓排列的最大和最小容许距离？ 3计算格构式轴心受压构件绕虚轴的整体稳定时，为什么采纳换算长细比？ 四、计算题（共计16分） 图所示的拉弯构件长6000mm，轴向拉力的设计值为800kN，横向均布荷载的设计值为7kN/m。设截面无减弱，钢材为Q345（ f=310N/mm2），构件采纳一般工字钢I22a，截面积A42.1cm2，重量0.32kN/m，Wx310cm3，ix8.99cm，iy2.32cm。验算截面是否满意设计要求。已知：允许长细比，截面塑性发展系数，荷载分项系数为1.0。公式： 试题答案及评分标准（供参考） 一、单项选择题（将每题正确答案的序号填入括号内，每小题2分，共计30分） 1B 2D 3B 4A 5A 6B 7B 8D 9D 10C 11D 12C 13A 14C 15C 二、推断题（正确的划“”，错误的划“×”每小题2分，共计30分） 1（） 2（×） 3（） 4（） 5（×） 6（×） 7（） 8（×） 9（） 10（×） 11（） 12（×） 13（） 14（×） 15（×） 三、简答题（每小题8分，共计24分） 以下是各个简答题的要点，可依据详细状况酌情给分 1什么是疲惫断裂？影响钢材疲惫强度的因素？ 答：钢材的疲惫断裂是微观裂纹在连续反复荷载作用下不断扩展直至断裂的脆性破坏。钢材的疲惫强度取决于构造状况（应力集中程度和残余应力）、作用的应力幅、反复荷载的循环次数。 2为何要规定螺栓排列的最大和最小容许距离？ 答：为了避开螺栓四周应力集中相互影响、钢板的截面减弱过多、钢板在端部被螺栓冲剪破坏、被连接板件间发生鼓曲现象和满意施工空间要求等，规定肋螺栓排列的最大和最小容许距离。 3计算格构式轴心受压构件绕虚轴的整体稳定时，为什么采纳换算长细比？ 答：格构式轴心受压构件，当绕虚轴失稳时，因肢件之间并不是连续的板而只是每隔肯定距离用缀条或缀板联系起来，构件的剪切变形较大，剪力造成的附加影响不能忽视。因此，采纳换算长细比来考虑缀材剪切变形对格构式轴心受压构件绕虚轴的稳定承载力的影响。 四、计算题（共计16分） 以下是本题的答案要点，可依据详细状况酌情给分 解：(1)验算强度 （4分） （4分） (2)验算长细比 （4分） （4分） 所选截面满意设计要求。 请您删除一下内容，O(_)O感谢！2015年中心电大期末复习考试小抄大全，电大期末考试必备小抄，电大考试必过小抄After earning his spurs in the kitchens of The Westin, The Sheraton, Sens on the Bund, and a sprinkling of other top-notch venues, Simpson Lu fi nally got the chance to become his own boss in November 2010. Sort of. The Shanghai-born chef might not actually own California Pizza Kitchen (CPK) but he is in sole charge of both kitchen and frontof- house at this Sinan Mansionsstalwart.  “Its certainly a responsibility to be the head chef, and then to have to manage the rest of the restaurant as well,“ the 31-year-old tells Enjoy Shanghai. “In hotels, for example, these jobs are strictly demarcated, so its a great opportunity to learn how a business operates across the board.“  It was a task that management back in sunny California evidently felt he was ready for, and a vote of confi dence from a company that, to date, has opened 250 outlets in 11 countries. And for added pressure, the Shanghai branch was also CPKs China debut.  “For sure it was a big step, and unlike all their other Asia operations that are franchises, they decided to manage it directly to begin with,“ says Simpson.  Two years ago a private franchisee took over the lease, but the links to CPK headquarters are still strong, with a mainland-based brand ambassador on hand to ensure the business adheres to its ethos of creating “innovative, hearth-baked pizzas“, a slice of PR blurb that Simpson insists lives up to the hype.  “They are very innovative,“ he says. “The problem with most fast food places is that they use the same sauce on every pizza and just change the toppings. Every one of our 16 pizza sauces is a unique recipe that has been formulated to complement the toppings perfectly.“  The largely local customer base evidently agrees and on Saturday and Sunday, at least, the place is teeming. The kids-eat-for-free policy at weekends is undoubtedly a big draw, as well as is the spacious second-fl oor layout overlooked by a canopy of green from Fuxing Park over the road.  The company is also focusing on increasing brand recognition and in recent years has taken part in outside events such as the regular California Week. Still, the sta are honest enough to admit that business could be better; as good, in fact, as in CPKs second outlet in the popular Kerry Parkside shopping mall in Pudong.  “Sinan Mansions has really struggled to get the number of visitors that were envisaged when it first opened, and it hasnt been easy for any of the tenants here,“ adds Simpson. “Were planning a third outlet in the city in 2015, and we will probably choose a shopping mall again because of the better foot traffic.“ The tearooms once frequented by Coco Chanel and Marcel Proust are upping sticks and coming to Shanghai, Xu Junqian visits the Parisian outpost with sweet treats. One thing the century-old Parisian tearoom Angelina has shown is that legendary fashion designer Coco Chanel not only had style and glamor but also boasted great taste in food, pastries in particular. One of the most popular tearooms in Paris, Angelina is famous for having once been frequented by celebrities such as Chanel and writer Marcel Proust. Now Angelina has packed up its French ambience, efficient service, and beautiful, comforting desserts and flown them to Shanghai. At the flagship dine-in and take-out space in Shanghai, everything mimics the original tearoom designed from the beginning of the 20th century, in Paris, the height of “Belle Epoque“. The paintings on the wall, for example, are exactly the same as the one that depicts the landscape of southern France, the hometown of the owner; and the small tables are intentional imitations of the ones that Coco Chanel once sat at every afternoon for hot chocolate. The famous hot chocolate, known as LAfricain, is a luxurious mixture of four types of cocoa beans imported from Africa, blended in Paris and then shipped to Shanghai. Its sinfully sweet, rich and thick as if putting a bar of melting chocolate directly on the tongue and the fresh whipped cream on the side makes a light, but equally gratifying contrast. It is also sold in glass bottles as takeaway. The signature Mont-Blanc chestnut cake consists of three parts: the pureed chestnut on top, the vanilla cream like stuffing, and the meringue as base. Get all three layers in one scoop, not only for the different textures but also various flavors of sweetness. The dessert has maintained its popularity for a century, even in a country like France, perhaps the worlds most competitive place for desserts. A much overlooked pairing, is the Paris-New York choux pastry and N226 chocolate flavored tea. The choux pastry is a mouthful of airy pecan-flavored whipped cream, while the tea, a blend of black teas from China and Ceylon, cocoa and rose petals, offers a more subtle fragrance of flowers and chocolate. Ordering these two items, featuring a muted sweetness, makes it easier for you to fit into your little black dress. Breakfast, brunch, lunch and light supper are also served at the tearoom, “a hub of many cultures“ and takes in “a mix of different styles of French cuisines“, according to the management team. The semi-cooked foie gras terrine, is seductive and deceptive. Its generously served at the size and shape of a toast, while the actual brioche toast is baked into a curved slice dipped with fig chutney. The flavor, however, is honest: strong, smooth and sublime. And you dont actually need the toast for crunchiness. This is the season for high teas, with dainty cups of fine china and little pastries that appeal to both visual and physical appetites. But there is one high tea with a difference, and Pauline D. Loh finds out just exactly why it is special. Earl Grey tea and macarons are all very well for the crucial recuperative break in-between intensive bouts of holiday season shopping. And for those who prefer savory to sweet, there is still the selection of classic Chinese snacks called dim sum to satisfy and satiate. High tea is a meal to eat with eye and mouth, an in-between indulgence that should be light enough not to spoil dinner, but sufficiently robust to take the edge off the hunger that strikes hours after lunch. The afternoon tea special at Shang-Xi at the Four Seasons Hotel Pudong has just the right elements. It is a pampering meal, with touches of luxury that make the high tea session a treat in itself. Whole baby abalones are braised and then topped on a shortcrust pastry shell, a sort of Chinese version of the Western vol-au-vent, but classier. Even classier is the dim sum staple shrimp dumpling or hargow, upgraded with the addition of slivers of midnight dark truffles. This is a master touch, and chef Simon Choi, who presides unchallenged at Shang-Xi, has scored a winner again. Sweet prawns and aromatic truffles whats not to love? His masterful craftsmanship is exhibited in yet another pastry a sweet pastry that is shaped to look like a walnut, but which you can put straight into the mouth. It crumbles immediately, and the slightly sweet, nutty morsel is so easy to eat youll probably reach straight for another. My favorite is the dessert that goes by the name yangzhi ganlu, or ambrosia from the gods. The hotel calls it chilled mango cream with sago, pomelo and birds nest made with ingredients that resonate with every female soul. It does taste like ambrosia, with the sweet-sour fragrance of the mango forming the first layer of taste and sensation, and the pomelo sacs and sago pearls providing the tactile contrast. The birds nest its the ingredient that gilds the lily, since it is supposed to nourish and nurture a perfect complexion. For those unfamiliar with this exotic ingredient, the birds nest is not a bundle of twigs, but is, instead, the dried secretion that cave swifts use to build their nest. Technically, its bird saliva, but the Chinese believe that it has collagen-boosting properties essential to beauty. To me, it just tastes good, adding a slight gelatinous crunch to the back of the teeth. There is also a baked mushroom puff pastry that includes the highly prized Matsutake or pine mushroom. You also get a choice of teas, but I strongly recommend the aged Puer from Yunnan province. It is a mellow tea that will go perfectly with the rich little nuggets, and will warm you up on a cold afternoon. Incidentally, the general guide is green tea such as Longjing or Dragonwell for the hot season, semi-fermented teas like Wu-long or Iron Buddha for autumn, and more warming teas like Puer for winter. The Shang-Xi afternoon tea costs 228 yuan ($37) per person, and 388 yuan for the more opule