【正文】
s time for the wild fruits to ripe. The picturesque Arxan in Autumn is indeed a fairyland only exists in a dream that satisfies all your fantasies. If it rains heavily on Saturday night, some elderly Chinese will say it is because Zhinu, or the Weaving Maid, is crying on the day she met her husband Niulang, or the Cowherd, on the Milky Way. Most Chinese remember being told this romantic tragedy when they were children on Qixi, or the Seventh Night Festival, which falls on the seventh day of the seventh lunar month, which is usually in early August. This year it falls on Saturday, August 2. Folklore Story As the story goes, once there was a cowherd, Niulang, who lived with his elder brother and sisterinlaw. But she disliked and abused him, and the boy was forced to leave home with only an old cow for pany. The cow, however, was a former god who had violated imperial rules and was sent to earth in bovine form. One day the cow led Niulang to a lake where fairies took a bath on earth. Among them was Zhinu, the most beautiful fairy and a skilled seamstress. The two fell in love at first sight and were soon married. They had a son and daughter and their happy life was held up as an example for hundreds of years in China. Yet in t。 ll wait in the line for one hour to get a ticket, and another two hours at the site, to only see a tiny bit of the place due to the crowds. Last year, 428 million tourists traveled in China over the weeklong holiday in October. Traveling during this period is a matter that needs thorough preparation. If you are short on time to plan the uping Golden Week it may not be a bad idea to avoid some of the most crowded places for now. There is always a place so fascinating that everyone yearns for. Arxan is a place like this. The beauty of Arxan is everlasting regardless of the changing of four seasons. Bestowed by nature, its spectacular seasonal landscape and mountains are just beyond word. Arxan is a crucial destination for the remended travelling route, China Inner Mongolia Arxan — Hailar — Manzhouli. It is also the joint of the four prairies across the SinoMongolian border, where people gravitate towards the exotic atmosphere mixed with Chinese, Russian, and Mongolia elements. As a historic site for the Yitian Battle, Arxan still embodies the spirit of Genghis Khan. Walking into Arxan, you will be amazed by a kaleidoscope of geous colors all the year round the Spring azaleas blooming red in the snow, the Summer sea wavering blue in the breeze, the Autumn leaves painted in yellow covering volcanic traces, and the Winter woods shining white on the vast alpine snowscape. Hinggan League Arxan city is situated in the far eastern area of Inner Mongolia Autonomous Region. Its full name Haren Arxan means hot holy water in the Mongolian language. Arxan is a tourism city in the northern frontier with a blend of large forest, grand prairies, vast snowfield, heaven lake cluster, thermium, as well as volcanic cluster. It is a rare and unique ecotourism base filled with healthy sunshine, clean air and unspoiled green. Nestled close to the country39。 最后感謝 ****大學(xué) 網(wǎng)絡(luò)教育二 年以來給予我學(xué)習(xí)與生活的平臺(tái),感謝 ****大學(xué) 網(wǎng)絡(luò)教育學(xué)院 。 感謝我的同學(xué),他們給我的畢業(yè)論文提出了很多很好的意見和建議,也幫助我解決了論文中遇到的不少困難,使我能夠順利完成論文。老師嚴(yán)謹(jǐn)?shù)墓ぷ髯黠L(fēng)、淵博的學(xué)識(shí)、誨人不倦的師德、誠(chéng)懇待人的品德使我永生不忘。首先我要向我的指導(dǎo)老師老師致以深深的謝意,感謝 老師在論文選題及整個(gè)論文完成過程中給予我的悉心指 導(dǎo)。 38 致謝 大學(xué)生活一晃而過,回首走過的大學(xué)二 年,心中倍感充實(shí)。 在過去的 50 年中,土力學(xué)這門科學(xué)及其與地質(zhì)過程的關(guān)系取得了很大的進(jìn)展。直到不久之前,僅僅將基礎(chǔ)工程與土力學(xué)相聯(lián)系,而將交界面構(gòu)件讓給結(jié)構(gòu)(或其他)工程師去處理的現(xiàn)象還很常見。了解土體形成所涉及的各種地質(zhì)過程也幾乎同等重要。顯然在上述任何一個(gè)例子中,如果 37 基礎(chǔ)工程師曾經(jīng)對(duì)現(xiàn)場(chǎng)附近的以往的工程提供過建議和 /或進(jìn)行過設(shè)計(jì),則對(duì)目前的工程將是有幫助的。一個(gè) 10 層的建筑物則需要更多的資料。 正確地運(yùn)用工程判斷要求基礎(chǔ)工程師要有場(chǎng)地的土質(zhì)剖面、土的性質(zhì)數(shù)據(jù)和足夠的地質(zhì)資料,以便于做出一個(gè)安全、經(jīng)濟(jì)和實(shí)際的決策。 在基礎(chǔ)工程實(shí)踐中,不難看出“工程判斷”起著重要的作用。 ( 2) 相對(duì)涉及的土的體積而言,土樣數(shù)量較少。當(dāng)考慮到實(shí)際土層的組成、其地質(zhì)因素的性質(zhì)以及很難取得所受到的干擾小到足以使試驗(yàn)數(shù)據(jù)可靠的試樣,所以實(shí)驗(yàn)室制備的土樣的實(shí)驗(yàn)數(shù)據(jù)同現(xiàn)場(chǎng)的土樣很少有相似之處。在實(shí)驗(yàn)室內(nèi)再現(xiàn)時(shí)效和環(huán)境過程,以獲取自燃膠結(jié)效果,通常會(huì)因?yàn)榛ㄙM(fèi)太多的時(shí)間而不切實(shí)際。這樣容易制成頗為各向同性、均質(zhì)的試樣,通常缺乏地質(zhì)時(shí)效的影響,因此一般不會(huì)形成各向異性和膠結(jié)作用這些性質(zhì)。 近年來,在實(shí)驗(yàn)室內(nèi)進(jìn)行了許多土的性質(zhì)方面的研究工作,并已經(jīng)在巖土工程文獻(xiàn)中發(fā)表。 ( 3) 土壓力。 掌握了關(guān)于上述這些性質(zhì)的知識(shí),可以使工程師能夠?qū)σ幌赂鞣矫孀龀龉浪悖? ( 1) 承載能力。 ( 3) 滲透性?;A(chǔ)工程師特別感興趣的那些性質(zhì)包括: ( 1) 強(qiáng)度參數(shù)(應(yīng)力 應(yīng)變模量、剪切模量、泊松比、內(nèi)聚力和內(nèi) 摩擦角)。 17(4):314— 320. 10. 邢靜忠,張軍 . [M] .北京:機(jī)械工業(yè)出版社, (1):7276. 11. Edward C. Smith, InderjitChopra. Aeroelastic Response, Loads, and Stability of a Composite Rotor in Forward F1ight. AI從 Journal. 1993: 42— 48. 12. 李德源,葉枝全,包能勝.風(fēng)力機(jī)旋轉(zhuǎn)風(fēng)輪振動(dòng)模態(tài)分析.太陽(yáng)能學(xué)報(bào), 2021 13. 金斯伯格.機(jī)械與結(jié)構(gòu)振動(dòng):理論與應(yīng)用 . 北京:中國(guó)寧航出版社, 2021 14. 鄧凡平編著 . ANSYS 有限元分析自學(xué)手冊(cè) [M],人民郵電出版社 . 15. 卞于中.風(fēng)力機(jī)葉片氣動(dòng)彈性實(shí)驗(yàn)研究.氣動(dòng)實(shí)驗(yàn)與測(cè)餐控制 . 1994, 8(3):40— 47. 16. 邵文秋 . ANSYS 有限元分析 [M].中國(guó)鐵道出版社 ,2021. 基礎(chǔ)工程中的土力學(xué) 沒有任何一種建筑材料的工程性質(zhì)和物理性質(zhì)像土那樣不勻稱。 通過以上的分析,在今后的利用軟件進(jìn)行分析和計(jì)算過程中,我們將會(huì)熟練的應(yīng)用到實(shí)際生活中的各種例子,以便求出更精確方便的設(shè)計(jì)方案??梢苑治鼋Y(jié)構(gòu)受載情況下的位移、變形以及應(yīng)力,從而了解結(jié)構(gòu)的危險(xiǎn)截面, 加以改進(jìn)。 ( 3) 在分析過程中運(yùn)用 ANSYS 進(jìn)行優(yōu)化設(shè)計(jì),根據(jù)內(nèi)力滿足條件,使得模型更加合理化。 ( 1) 在通過對(duì)以上的求解中,發(fā)現(xiàn)應(yīng)力、應(yīng)變、位移,變形情況基符合理論要求。 通過整章的有限元優(yōu)化設(shè)計(jì)分析,了解 ANSYS 軟件通過優(yōu)化設(shè)計(jì),尋找確定最優(yōu)設(shè)計(jì)方案的技術(shù),熟練優(yōu)化設(shè)計(jì)的過程與步驟。 32 圖 優(yōu)化 —— 四階模態(tài)圖 對(duì)于四階模態(tài)分析圖,可知它的振動(dòng)是在 Y軸方向進(jìn)行上下振動(dòng),由四階模態(tài)圖知其頻率為 Hzf ? 。 圖 優(yōu)化 —— 二階模態(tài)圖 對(duì)于二階模態(tài)分析圖,可知它的振動(dòng)是在平行于 YZ 的平面內(nèi)振動(dòng) ,由二階模態(tài)圖知其頻率為 Hzf ? 。 圖 優(yōu)化 —— 應(yīng)力圖 29 由優(yōu)化后的應(yīng)力圖可以看出,塔架最大應(yīng)力值為 。 優(yōu)化后的模型塔架采用 : Beam 3D elastic 4 單元,此單元截面分別是: 3mm3mm和 2mm2mm 的矩形截面; 發(fā)電機(jī)模型仍然采用: Solid Brick 8node 45 單元,此發(fā)電機(jī)模型結(jié)構(gòu)是: 26 150mm150mm 的鋼制三棱柱。 重新建立模型,采用優(yōu)化后的數(shù) 據(jù)。其最大位移值由原來的 ,應(yīng)力值由原來的 變?yōu)?。 指定優(yōu)化變量:兩個(gè)截面尺寸分別為 6mm6mm和 6mm2mm ; 優(yōu)化滿足條件 : ( 1)位移最大值小于等于 7mm ; ( 2)應(yīng)力最大值小于等于 10MPa。 ( 7) 進(jìn)行優(yōu)化分析。 ( 5) 選擇優(yōu)化工具或優(yōu)化方法。 ( 3) 進(jìn)入 OPT 處理器指定分析文件。參數(shù)化建立模型( PREP7);求解( SOLUTION);提取并指定狀態(tài)變量和目標(biāo)函數(shù)( POST1/POST26)。 25 優(yōu)化設(shè)計(jì)通常包括以下步驟,這些步驟根據(jù)所用優(yōu)化方法不同有細(xì)微差別。使用GUI 方式時(shí)首先要建立模型的分析文件,然后可交互式使用優(yōu)化處理器的功能以確定設(shè)計(jì)空間,便于后續(xù)優(yōu)化處理。 優(yōu)化設(shè)計(jì)的過程與步驟 ANSYS 優(yōu)化設(shè)計(jì)可以通過批處理方式和 GUI 方式實(shí)現(xiàn),一般來說,如果用戶對(duì)于 ANSYS 命令相當(dāng)熟悉,可選擇用命令輸入整個(gè)優(yōu)化文件并通過批處理方式優(yōu)化。 ANSYS 還提供了一系列的優(yōu)化工具以提高優(yōu)化過程的效率,例如可以指定隨機(jī)優(yōu)化分析的迭代次數(shù),隨機(jī)計(jì)算結(jié)果的初始值可以作為優(yōu)化過程的起點(diǎn)數(shù)值。即分析初始設(shè)計(jì),基于設(shè)計(jì)要求評(píng)