發(fā)布時(shí)間：2018-02-23 04:12

  本文關(guān)鍵詞： 顆粒增強(qiáng)鋁基復(fù)合材料 本構(gòu)方程 損傷演化模型 強(qiáng)力旋壓 數(shù)值模擬　出處：《北京有色金屬研究總院》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：顆粒增強(qiáng)鋁基復(fù)合材料具有高比強(qiáng)度、高比剛度、高耐磨性、高尺寸穩(wěn)定性、低密度和低熱膨脹系數(shù)等一系列優(yōu)異的綜合性能,在先進(jìn)武器裝備和航天技術(shù)領(lǐng)域有良好應(yīng)用前景。強(qiáng)力旋壓具有材料利用率高、加工靈活、適合制造大徑厚比管材等優(yōu)勢(shì),是加工復(fù)合材料管材的有效方法。顆粒增強(qiáng)鋁基復(fù)合材料在強(qiáng)力旋壓加工過(guò)程中,由于增強(qiáng)體的存在,基體的連續(xù)性容易被破壞,其塑性會(huì)降低,成形零件不可避免會(huì)產(chǎn)生內(nèi)部微裂紋,即為損傷。微裂紋不斷長(zhǎng)大和匯合,最終會(huì)引發(fā)復(fù)合材料的宏觀斷裂。本文采用建立復(fù)合材料損傷演化模型和數(shù)值模擬相結(jié)合的方式,預(yù)測(cè)復(fù)合材料在高溫變形過(guò)程中的宏觀斷裂現(xiàn)象以及強(qiáng)力旋壓加工過(guò)程中損傷值的變化規(guī)律,為實(shí)際生產(chǎn)工藝制定和優(yōu)化提供理論依據(jù)。本文對(duì)顆粒增強(qiáng)鋁基復(fù)合材料進(jìn)行了熱模擬實(shí)驗(yàn),得到了該材料高溫變形條件下的應(yīng)力應(yīng)變曲線,建立了材料的高溫本構(gòu)方程,計(jì)算了本構(gòu)方程的相關(guān)參數(shù),并對(duì)本構(gòu)方程進(jìn)行了實(shí)驗(yàn)對(duì)比驗(yàn)證,結(jié)果顯示誤差值為3.8%,說(shuō)明該本構(gòu)方程能夠較好的描述復(fù)合材料的高溫流變行為。基于連續(xù)損傷力學(xué)理論,考慮變形溫度和應(yīng)變速率的影響,建立了顆粒增強(qiáng)鋁基復(fù)合材料高溫變形過(guò)程中的損傷演化模型。利用Lemaitre提出的彈性模量法進(jìn)行高溫多道次拉伸實(shí)驗(yàn),得到了復(fù)合材料不同變形條件下的損傷演化曲線。對(duì)損傷演化曲線數(shù)據(jù)擬合確定了模型參數(shù)為A(Z)=2.22769-0.09438In Z+0.00238ln2 Z,對(duì)損傷臨界值擬合確定了復(fù)合材料宏觀斷裂的判斷依據(jù)為DC(Z)=0.50915-0.00577ln Z。采用高溫壓縮實(shí)驗(yàn)對(duì)損傷演化模型進(jìn)行驗(yàn)證,結(jié)果表明該模型可以較好的預(yù)測(cè)復(fù)合材料在高溫變形過(guò)程中的宏觀斷裂現(xiàn)象�；谀M軟件,建立了顆粒增強(qiáng)鋁基復(fù)合材料強(qiáng)力旋壓有限元模型。在軟件中耦合了損傷演化模型,并導(dǎo)入了損傷參數(shù)。通過(guò)數(shù)值模擬,分析了復(fù)合材料強(qiáng)力旋壓過(guò)程中應(yīng)力應(yīng)變的變化規(guī)律,旋輪接觸區(qū)三向應(yīng)力的大小,材料流動(dòng)的穩(wěn)定性以及損傷值的變化規(guī)律。并討論了不同旋壓溫度、減薄率和進(jìn)給比對(duì)復(fù)合材料強(qiáng)力旋壓等效應(yīng)力和損傷值的影響。結(jié)果顯示損傷值隨溫度的升高而降低,隨減薄率的增加而升高,隨進(jìn)給比的增加而升高。繪制了損傷值的三維曲面,通過(guò)曲面圖可以選擇材料加工的安全參數(shù)范圍,避免材料發(fā)生宏觀斷裂。通過(guò)物理實(shí)驗(yàn)對(duì)數(shù)值模擬的預(yù)測(cè)進(jìn)行驗(yàn)證,結(jié)果較為吻合。
[Abstract]:Particle reinforced aluminum matrix composites have a series of excellent properties, such as high specific strength, high specific stiffness, high wear resistance, high dimensional stability, low density and low coefficient of thermal expansion. It has a good application prospect in the field of advanced weapon equipment and aerospace technology. Strong spinning has the advantages of high material utilization ratio, flexible processing, suitable for manufacturing large diameter to thickness ratio pipe, etc. Particle reinforced aluminum matrix composites are easy to be destroyed because of the existence of reinforcements, and their plasticity will be reduced. It is inevitable that the forming parts will produce internal microcracks, that is, damage. The microcracks will grow and converge, which will eventually lead to the macroscopic fracture of composite materials. In this paper, the damage evolution model and numerical simulation of composite materials are established by combining the damage evolution model and numerical simulation. The macroscopic fracture phenomenon of composites during high temperature deformation and the variation of damage value during the process of strength spinning are predicted. In this paper, the thermal simulation experiments of particle reinforced aluminum matrix composites are carried out, the stress-strain curves of the materials under high temperature deformation are obtained, and the constitutive equations of the materials at high temperature are established. The related parameters of the constitutive equation are calculated, and the experimental results show that the error is 3.8. the result shows that the constitutive equation can describe the rheological behavior of composites at high temperature. Based on the theory of continuous damage mechanics, the constitutive equation can describe the rheological behavior of composites at high temperature. Considering the influence of deformation temperature and strain rate, the damage evolution model of grain reinforced aluminum matrix composites during high temperature deformation was established. The elastic modulus method proposed by Lemaitre was used to carry out multi-pass tensile tests at high temperature. The damage evolution curves of composite materials under different deformation conditions were obtained, and the model parameters were determined as Agna 2.22769-0.09438In Z 0.00238ln2Z by fitting the data of damage evolution curves, and the judgment basis for the macroscopic fracture of composites was determined as follows: 1. DC(Z)=0.50915-0.00577ln Z. the damage evolution model is verified by high temperature compression test. The results show that the model can be used to predict the macroscopic fracture of composites during high temperature deformation. In this paper, a finite element model for the strength spinning of particle reinforced aluminum matrix composites is established. The damage evolution model is coupled in the software, and the damage parameters are introduced. Through numerical simulation, the variation of stress and strain in the process of strength spinning of the composite is analyzed. The magnitude of triaxial stress in the contact zone of rotary wheel, the stability of material flow and the variation of damage value are discussed, and the different spinning temperatures are discussed. The effect of thinning rate and feed ratio on the equivalent stress and damage value of the composite strength spinning shows that the damage value decreases with the increase of temperature and increases with the increase of thinning rate. With the increase of feed ratio, the 3D surface with damage value is drawn, and the safety parameter range of material processing can be selected by the surface diagram, which can avoid the macroscopic fracture of material. The prediction of numerical simulation is verified by physical experiments. The results are in good agreement.
【學(xué)位授予單位】：北京有色金屬研究總院
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB333

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 徐文臣;單德彬;陳宇;康達(dá)昌;呂炎;;鈦合金薄壁筒形件熱旋成形技術(shù)研究[J];鍛壓技術(shù);2008年03期

2 段慧玲,王建祥,黃筑平,黃紅波;顆粒增強(qiáng)復(fù)合材料的界面模型與界面相模型的關(guān)系[J];復(fù)合材料學(xué)報(bào);2004年03期

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本文編號(hào)：1526093