本文選題：功能梯度材料 + 薄球殼　； 參考：《太原科技大學(xué)》2017年碩士論文

【摘要】：近年來,隨著高新技術(shù)領(lǐng)域快速發(fā)展,對材料的要求越來越高,功能梯度材料特別適用于材料兩側(cè)溫差較大的環(huán)境,其耐熱性、再用性和可靠性是以往使用的陶瓷基復(fù)合材料無法比擬的。功能梯度材料采用先進(jìn)的材料復(fù)合技術(shù),通過金屬、陶瓷、塑料等材料的巧妙組合,使材料的性質(zhì)和功能沿厚度方向呈梯度變化的一種新型復(fù)合材料。因其優(yōu)異的的力學(xué)性能和新穎的設(shè)計(jì)的思想被廣泛的運(yùn)用在航天、醫(yī)學(xué)、電磁、核工程、光學(xué)等領(lǐng)域。板殼結(jié)構(gòu)在各行各業(yè)有著廣泛的應(yīng)用,結(jié)構(gòu)的穩(wěn)定性問題是實(shí)際工程應(yīng)用中需要解決的問題之一。怎樣準(zhǔn)確的預(yù)測到板殼結(jié)構(gòu)發(fā)生屈曲時的臨界點(diǎn),一直是現(xiàn)在科研人員需要突破的難題之一。尤其是熱屈曲問題,需要同時準(zhǔn)確得到臨界壓力和臨界溫度。由于功能梯度材料大多運(yùn)用在高新技術(shù)領(lǐng)域,對結(jié)構(gòu)的熱穩(wěn)定性的準(zhǔn)確性要求更高。所以對功能梯度材料板殼熱屈曲的研究顯得非常的重要。本文研究了功能梯度材料薄球殼在線性和非線性情況下的熱屈曲問題,為功能梯度材料薄球殼在工程實(shí)際運(yùn)用中提供有價值的參考。1,本文在各向同性完備的非線性熱本構(gòu)方程的基礎(chǔ)上,通過christoffel符號表示基矢量對坐標(biāo)的導(dǎo)數(shù),推導(dǎo)出功能梯度薄球殼在球坐標(biāo)系下的熱本構(gòu)方程。2,用張量方法推導(dǎo)得到了軸對稱球殼穩(wěn)定性方程。將熱本構(gòu)方程應(yīng)用到球殼穩(wěn)定性方程中,得到以位移表示的球殼熱屈曲方程組。3,在線性的情況下,分別考慮均布外壓和溫度作用下,采用伽遼金法和里茲法研究了簡支球殼的熱屈曲問題。分析了薄球殼厚度和物性參數(shù)變化引起的臨界壓力變化趨勢和臨界溫度的變化趨勢。4,在非線性的情況下,應(yīng)用里茲法分析了簡支半球的熱屈曲問題。研究了(1)在不同外壓溫度(沒有達(dá)到臨界溫度)作用下,臨界壓力和厚度的關(guān)系;(2)在不同厚度下,臨界壓力與溫度的關(guān)系;(3)在不同外壓載荷(沒有達(dá)到臨界壓力)作用下,臨界溫度與厚度的關(guān)系。
[Abstract]:In recent years, with the rapid development of the field of high and new technology, the demand for materials is becoming higher and higher. FGM is especially suitable for the environment with large temperature difference on both sides of the material, and its heat resistance. The reusability and reliability are unparalleled by the ceramic matrix composites used in the past. The functionally graded material (FGM) is a new kind of composite material, whose properties and functions change along the thickness direction through the clever combination of metal, ceramic, plastic and so on. Because of its excellent mechanical properties and novel design ideas, it has been widely used in aerospace, medicine, electromagnetic, nuclear engineering, optics and other fields. Plate and shell structures are widely used in various industries, and the stability of structures is one of the problems to be solved in practical engineering applications. How to accurately predict the critical point of buckling of plate and shell structure has always been one of the difficult problems that the researchers need to break through. Especially for thermal buckling problem, critical pressure and critical temperature must be accurately obtained simultaneously. As functionally gradient materials are mostly used in high-tech fields, the accuracy of thermal stability of structures is higher. Therefore, it is very important to study the thermal buckling of functionally graded materials (FGM) plates and shells. In this paper, the thermal buckling of thin spherical shells with functionally graded materials under linear and nonlinear conditions is studied. In order to provide a valuable reference for the thin spherical shell with functionally graded materials in engineering application, based on the isotropic complete nonlinear thermal constitutive equation, the derivative of base vector to coordinates is expressed by christoffel symbol. The thermal constitutive equation of functionally graded thin spherical shell in spherical coordinate system is derived. The stability equation of axisymmetric spherical shell is derived by Zhang Liang method. The thermal constitutive equation is applied to the stability equation of spherical shell, and the thermal buckling equation of spherical shell expressed by displacement is obtained. In the linear case, the uniform external pressure and temperature are considered, respectively. The thermal buckling of simply supported spherical shells is studied by Galerkin method and Ritz method. The variation trend of critical pressure and critical temperature caused by the change of thickness and physical parameters of thin spherical shell is analyzed. The thermal buckling problem of simply supported hemispheres is analyzed by using the Ritz method in the case of nonlinearity. The relationship between critical pressure and thickness under different external pressure temperature (not reaching critical temperature) is studied. Under different thickness, the relationship between critical pressure and temperature is studied. (3) under different external pressure loads (no critical pressure is reached), The relation between critical temperature and thickness.
【學(xué)位授予單位】：太原科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O344.1

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 王豫,姚凱倫;功能梯度材料研究的現(xiàn)狀與將來發(fā)展[J];物理;2000年04期

2 何沛祥,李子然,吳長春;無網(wǎng)格法與有限元法的耦合及其對功能梯度材料斷裂計(jì)算的應(yīng)用[J];中國科學(xué)技術(shù)大學(xué)學(xué)報;2001年06期

3 鄭慧雯,茹克也木·沙吾提,章嫻君;功能梯度材料的研究進(jìn)展[J];西南師范大學(xué)學(xué)報(自然科學(xué)版);2002年05期

4 陳英儒,肖洪天,汪小敏,高英;功能梯度材料中裂紋問題的邊界元分析[J];山東科技大學(xué)學(xué)報(自然科學(xué)版);2004年04期

5 肖洪天,岳中琦;平行于功能梯度材料夾層的幣型裂紋起裂條件[J];固體力學(xué)學(xué)報;2005年01期

6 吳曉;黃，

本文編號：1976866