a国产,中文字幕久久波多野结衣AV,欧美粗大猛烈老熟妇,女人av天堂

當(dāng)前位置:主頁 > 科技論文 > 材料論文 >

復(fù)合材料層合板結(jié)構(gòu)非局部漸進失效建模與有限元分析

發(fā)布時間:2018-06-25 13:16

  本文選題:碳纖維復(fù)合材料層合板 + 漸進失效分析方法��; 參考:《浙江大學(xué)》2015年碩士論文


【摘要】:碳纖維增強復(fù)合材料由碳纖維增強體和樹脂基體組成,它具有一系列優(yōu)異性能,如高強度、可設(shè)計性強、低密度、低熱膨脹系數(shù)等,是先進材料領(lǐng)域重點開發(fā)、研究的一種結(jié)構(gòu)材料,具有良好的應(yīng)用前景。然而,復(fù)合材料失效機理通常非常復(fù)雜,對強度、剛度、損傷容限以及剩余壽命的評估和預(yù)測提出了較大挑戰(zhàn)。目前,國內(nèi)外在復(fù)合材料漸進失效領(lǐng)域已經(jīng)開展了諸多研究,然而通常實際應(yīng)用中的復(fù)合材料幾何形狀和失效機理復(fù)雜,經(jīng)常導(dǎo)致應(yīng)力集中和局部化問題,根本特征是剛度退化帶來的應(yīng)變軟化問題,這使得運用常規(guī)有限元分析結(jié)構(gòu)力學(xué)性能失去客觀性,數(shù)值求解失去意義。這是因為局部化問題自然引入了尺度比例而連續(xù)介質(zhì)力學(xué)缺乏尺度比例參數(shù)。目前國內(nèi)外在復(fù)合材料局部化問題的研究非常少。本文基于非局部積分理論和連續(xù)損傷力學(xué)理論,針對碳纖維復(fù)合材料層合板結(jié)構(gòu),基于ABAQUS有限元軟件發(fā)展了有限元數(shù)值計算技術(shù),開展了非局部漸進失效分析,深入研究了含中心開孔復(fù)合材料層合板的漸進失效機理和強度。取得的研究進展如下:(1)建立了復(fù)合材料層合板漸進失效分析預(yù)測理論模型,確定了以等效應(yīng)變作為判斷纖維和基體失效的參量,推導(dǎo)了針對纖維斷裂和基體開裂損傷變量的破壞進化律及一致切線模量,為復(fù)合材料的強度預(yù)測提供理論支撐。(2)基于非局部積分理論,將控制應(yīng)變軟化的內(nèi)變量-等效應(yīng)變進行非局部平均處理,從而在模型中引入針對纖維和基體的兩個尺度比例參數(shù),最后針對隱式有限元求解問題,推導(dǎo)了各向異性非局部一致切線模量,為解決復(fù)合材料應(yīng)變局部化問題提供了理論基礎(chǔ)。(3)運用ABAQUS-UEL(用戶自定義單元子程序模塊),UMAT(用戶自定義材料子程序模塊),USDFLD(用戶場變量子程序模塊)和UEXTERNALDB(用戶外部數(shù)據(jù)接口應(yīng)用子程序模塊),開展數(shù)值編程,實現(xiàn)了提出的非局部漸進失效模型,從而形成了復(fù)合材料非局部漸進失效分析數(shù)值計算技術(shù)。(4)針對含中心圓孔復(fù)合材料層合板結(jié)構(gòu),運用上述提出的非局部漸進失效理論模型,開展了非局部有限元分析,與試驗結(jié)果進行比較,探討了開孔半徑、鋪層方式、網(wǎng)格尺寸和非局部尺度比例參數(shù)對復(fù)合材料層合板漸進失效特性和強度、剛度的影響規(guī)律。
[Abstract]:Carbon fiber reinforced composites are composed of carbon fiber reinforcements and resin matrix. It has a series of excellent properties, such as high strength, high designability, low density, low thermal expansion coefficient and so on. A kind of structural material studied in this paper has a good prospect of application. However, the failure mechanism of composite materials is usually very complex, which poses a great challenge to the evaluation and prediction of strength, stiffness, damage tolerance and residual life. At present, many researches have been carried out in the field of progressive failure of composite materials at home and abroad. However, the geometric shape and failure mechanism of composite materials in practical applications are often complicated, which often lead to the problem of stress concentration and localization. The fundamental characteristic is the strain softening problem caused by stiffness degradation, which makes the use of conventional finite element analysis of the mechanical properties of the structure lose objectivity, and the numerical solution is meaningless. This is because the localization problem naturally introduces the scale and the continuum mechanics lacks the scale parameter. At present, there are few researches on localization of composite materials at home and abroad. Based on the nonlocal integral theory and the theory of continuous damage mechanics, the finite element numerical calculation technology is developed based on Abaqus finite element software for carbon fiber composite laminated plate structure, and the nonlocal progressive failure analysis is carried out. The progressive failure mechanism and strength of composite laminates with central holes were studied. The research progress is as follows: (1) A theoretical model of progressive failure analysis and prediction of composite laminates is established, and the equivalent strain is used as the parameter to judge the failure of fiber and matrix. The damage evolution law and uniform tangent modulus for fiber fracture and matrix cracking damage variables are derived, which provide theoretical support for the strength prediction of composites. (2) based on the nonlocal integral theory, The internal variable, equivalent strain, which controls strain softening, is treated with non-local average, and two scale proportional parameters for fiber and matrix are introduced into the model. Finally, the implicit finite element method is used to solve the problem. The anisotropic nonlocal uniform tangent modulus is derived. It provides a theoretical basis for solving the strain localization problem of composite materials. (3) using AbaquUS-UEL (user-defined unit subroutine module) UMAT (user-defined material subroutine module) USDFLD (user field variable subroutine module) and UEXTERNALDB (user external data) Interface application subroutine module), carry out numerical programming, The proposed nonlocal progressive failure model is realized, and the numerical calculation technique for nonlocal progressive failure analysis of composite materials is formed. (4) for the composite laminated plate structure with a central circular hole, the above proposed nonlocal progressive failure theory model is used. The non-local finite element analysis was carried out and compared with the experimental results. The effects of the opening radius, layering mode, mesh size and non-local scale ratio parameters on the progressive failure characteristics, strength and stiffness of composite laminates were discussed.
【學(xué)位授予單位】:浙江大學(xué)
【學(xué)位級別】:碩士
【學(xué)位授予年份】:2015
【分類號】:TB33

【參考文獻】

相關(guān)期刊論文 前2條

1 王向陽,陳建橋,張謝東;纖維增強復(fù)合材料層合板的概率逐步失效分析[J];武漢理工大學(xué)學(xué)報(交通科學(xué)與工程版);2004年06期

2 張博平;李亞智;;低速沖擊下復(fù)合材料層合板的三維損傷[J];機械強度;2007年05期

,

本文編號:2066070

資料下載
論文發(fā)表

本文鏈接:http://www.wukwdryxk.cn/kejilunwen/cailiaohuaxuelunwen/2066070.html


Copyright(c)文論論文網(wǎng)All Rights Reserved | 網(wǎng)站地圖 |

版權(quán)申明:資料由用戶3358e***提供,本站僅收錄摘要或目錄,作者需要刪除請E-mail郵箱bigeng88@qq.com
18禁成年免费无码国产| 久久99精品国产99久久| 人人鲁人人莫人人爱精品 | 一本久久a久久精品综合| 亚洲国在人成线| 精品欧洲AV无码一区二区男男| 国产乱子伦无码精品小说| 亚洲精选av| 人妻精品久久久久中文字幕一冢本| 无码少妇精品一区二区免费动态 | 自拍偷在线精品自拍偷99| 亚洲AV无码专区日韩乱码不卡 | 白浆网站| 久久精品99久久香蕉国产色戒| 男宠被强制灌水锁精憋尿| 亚洲中文字幕久在线| 伦人伦XXXX国语对白| 好吊色欧美一区二区三区视频| 黄色有几种黄色的颜色| 亚洲日本va中文字幕久久| 国产精品亚亚洲欧关中字幕| 日本高清视频WWW| 日韩精品人妻系列无码专区| 亚洲精品久久久久久久久久久| 97人妻天天摸天天爽天天| 亚洲欧美一区二区三区三| 国产成人综合久久免费| 欧美人与禽zoz0性伦交| 免费人成视频| 麻豆精品人妻一区二区三区蜜桃 | 黑人巨茎大战白人美女| 免费A级毛片又大又粗又黑| 色婷婷av一区二区三区仙踪林| 国产成人精品免高潮在线观看| 日韩高清在线观看| av天堂免费| 国产亚洲精品美女久久久久久| 国产男女爽爽爽免费视频| 国产办公室秘书无码精品99| 久久香蕉国产线看观看精品yw| 国产免费AV片在线播放唯爱网|