功能密度梯度泡沫鋁及其填充結(jié)構(gòu)的吸能性能研究
發(fā)布時(shí)間：2019-01-05 10:58
【摘要】：功能密度梯度泡沫鋁填充錐形薄壁結(jié)構(gòu)是汽車低速碰撞保護(hù)中極具應(yīng)用前景的吸能緩沖結(jié)構(gòu),為了更好地在受力條件復(fù)雜的汽車碰撞中設(shè)計(jì)和優(yōu)化泡沫鋁填充錐形薄壁結(jié)構(gòu),進(jìn)行單軸壓縮狀態(tài)下功能密度泡沫鋁填充錐形薄壁結(jié)構(gòu)的試驗(yàn),并觀察其變形模式和吸能機(jī)理,同時(shí)得到準(zhǔn)確的有限元模型是十分必要的;從另一個(gè)方面考慮,由于在泡沫鋁產(chǎn)品中觀察到天然存在的在重力方向上的密度變化,因此,在將泡沫鋁應(yīng)用到汽車吸能結(jié)構(gòu)時(shí),必須充分考慮泡沫鋁在重力方向上的密度變化特性對(duì)仿真建模的影響以得到準(zhǔn)確的有限元模型。為了更好地理解功能密度泡沫鋁填充錐形薄壁結(jié)構(gòu)的吸能性能,為設(shè)計(jì)和優(yōu)化泡沫鋁吸能結(jié)構(gòu)提供直觀的依據(jù),本文通過試驗(yàn)觀察和仿真分析,對(duì)比了截面形狀為四邊形和六邊形的功能密度泡沫鋁椎體、鋁合金薄壁錐形結(jié)構(gòu)、泡沫鋁填充錐形薄壁結(jié)構(gòu),在單軸準(zhǔn)靜態(tài)壓縮工況下的吸能性能。對(duì)比項(xiàng)目包括各結(jié)構(gòu)的變形模式、載荷-位移曲線、總吸能量(Absorbed Energy,AE)和比吸能(Specific Absorbed Energy,SAE)。本文使用通用有限元計(jì)算程序LS-DYNA進(jìn)行仿真分析,仿真中的材料模型參數(shù)均由其標(biāo)準(zhǔn)材料性能測(cè)試試驗(yàn)的結(jié)果中擬合提取,其中泡沫鋁的材料模型使用的是DeshpandeFleck泡沫材料模型(2000),即LS-DYNA材料卡片MAT_154。本文還使用了Hanssen等(2002)提出的泡沫鋁密度模型對(duì)本文中使用的泡沫鋁材料進(jìn)行描述,該模型使用泡沫鋁三個(gè)及以上密度的材料性能參數(shù)作為擬合值,得到描述任意密度下材料性能參數(shù)的函數(shù)。在建立泡沫鋁椎體有限元模型時(shí),由于泡沫鋁椎體試樣的密度分布和變化規(guī)律不可知,本文展示了得到準(zhǔn)確仿真分析結(jié)果的實(shí)踐性方法和在特定密度變化梯度下不同的建模方法對(duì)有限元模型精度的影響。同時(shí)為了增強(qiáng)各結(jié)構(gòu)的仿真結(jié)果的對(duì)比性,在保證仿真精度的前提下,本文在仿真分析中對(duì)不同截面形狀的泡沫鋁椎體模型進(jìn)行了相同的設(shè)置。通過對(duì)比各結(jié)構(gòu)的試驗(yàn)和仿真分析變形模式和吸能性能評(píng)價(jià)參數(shù),本文發(fā)現(xiàn),在單軸準(zhǔn)靜態(tài)壓縮工況下,截面形狀對(duì)泡沫鋁椎體和泡沫鋁填充錐形薄壁結(jié)構(gòu)的吸能性能影響不大;此外,泡沫鋁填充錐形薄壁結(jié)構(gòu)的吸能能力優(yōu)于單獨(dú)壓縮泡沫鋁椎體和薄壁錐形結(jié)構(gòu)的吸能能力的數(shù)值和。對(duì)具有密度變化的泡沫鋁椎體試樣建立有限元模型時(shí)發(fā)現(xiàn),對(duì)泡沫鋁椎體的密度分布進(jìn)行仿真時(shí)需要綜合考慮泡沫鋁標(biāo)定試驗(yàn)的試樣尺寸和密度變化梯度及泡沫鋁椎體試樣的幾何尺寸。
[Abstract]:Function-density gradient aluminum filled tapered thin-walled structure is an energy absorbing buffer structure with great application prospect in automobile low-speed impact protection. In order to better design and optimize foamed aluminum filled conical thin-walled structure in automobile crash with complicated stress conditions. It is necessary to test the conical thin-walled structure filled with functional density aluminum foam under uniaxial compression, observe its deformation mode and energy absorption mechanism, and obtain an accurate finite element model at the same time. On the other hand, because naturally occurring density changes in the gravity direction are observed in aluminum foam products, when applied to automotive energy absorption structures, The influence of density variation in the direction of gravity of aluminum foam on simulation modeling must be fully considered in order to obtain an accurate finite element model. In order to better understand the energy absorption performance of function-density aluminum foam filled conical thin-walled structure and to provide an intuitive basis for the design and optimization of aluminum foam energy absorption structure, this paper is based on experimental observation and simulation analysis. The energy absorption properties of functional density aluminum foam vertebrae with quadrilateral and hexagonal sections, aluminum alloy thin-walled conical structures and aluminum foam filled conical thin-walled structures under uniaxial quasi-static compression are compared. The contrast items include deformation mode, load-displacement curve, total energy absorption (Absorbed Energy,AE) and specific energy absorption (Specific Absorbed Energy,SAE) of each structure. In this paper, the general finite element program LS-DYNA is used to simulate and analyze the parameters of the material model. The parameters of the material model are extracted from the results of the test of the performance of the standard material. The material model of aluminum foam is DeshpandeFleck foam material model (2000), that is, LS-DYNA material card MAT_154. This paper also uses the foam aluminum density model proposed by Hanssen et al. (2002) to describe the aluminum foam materials used in this paper. The model uses the material properties of three or more densities of aluminum foam as the fitting value. A function describing the properties of materials at any density is obtained. When the finite element model of foam aluminum vertebra is established, the density distribution and variation law of foam aluminum vertebral body are unknown. In this paper, the practical methods to obtain accurate simulation results and the influence of different modeling methods on the accuracy of the finite element model under the specific density gradient are shown. At the same time, in order to enhance the comparison of the simulation results of each structure, under the premise of ensuring the simulation accuracy, the same setting of the foam aluminum vertebral body model with different cross-section shape is carried out in this paper. By comparing the experimental and simulation analysis of different structures, it is found that under the uniaxial quasi-static compression condition, the deformation mode and the energy absorption performance evaluation parameters are analyzed. The shape of section has little effect on the energy absorption performance of foamed aluminum vertebrae and foamed aluminum filled conical thin-walled structure. In addition, the energy absorption capacity of aluminum foam filled conical thin-walled structure is better than that of compression foam aluminum vertebra and thin-walled conical structure. The finite element model of foam aluminum vertebrae with density change is found. When simulating the density distribution of foam aluminum vertebrae, it is necessary to consider the sample size and density change gradient of foam aluminum calibration test and the geometric dimension of foam aluminum vertebral sample.
【學(xué)位授予單位】：湖南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TG146.21;TB383.4
本文編號(hào)：2401689
[Abstract]:Function-density gradient aluminum filled tapered thin-walled structure is an energy absorbing buffer structure with great application prospect in automobile low-speed impact protection. In order to better design and optimize foamed aluminum filled conical thin-walled structure in automobile crash with complicated stress conditions. It is necessary to test the conical thin-walled structure filled with functional density aluminum foam under uniaxial compression, observe its deformation mode and energy absorption mechanism, and obtain an accurate finite element model at the same time. On the other hand, because naturally occurring density changes in the gravity direction are observed in aluminum foam products, when applied to automotive energy absorption structures, The influence of density variation in the direction of gravity of aluminum foam on simulation modeling must be fully considered in order to obtain an accurate finite element model. In order to better understand the energy absorption performance of function-density aluminum foam filled conical thin-walled structure and to provide an intuitive basis for the design and optimization of aluminum foam energy absorption structure, this paper is based on experimental observation and simulation analysis. The energy absorption properties of functional density aluminum foam vertebrae with quadrilateral and hexagonal sections, aluminum alloy thin-walled conical structures and aluminum foam filled conical thin-walled structures under uniaxial quasi-static compression are compared. The contrast items include deformation mode, load-displacement curve, total energy absorption (Absorbed Energy,AE) and specific energy absorption (Specific Absorbed Energy,SAE) of each structure. In this paper, the general finite element program LS-DYNA is used to simulate and analyze the parameters of the material model. The parameters of the material model are extracted from the results of the test of the performance of the standard material. The material model of aluminum foam is DeshpandeFleck foam material model (2000), that is, LS-DYNA material card MAT_154. This paper also uses the foam aluminum density model proposed by Hanssen et al. (2002) to describe the aluminum foam materials used in this paper. The model uses the material properties of three or more densities of aluminum foam as the fitting value. A function describing the properties of materials at any density is obtained. When the finite element model of foam aluminum vertebra is established, the density distribution and variation law of foam aluminum vertebral body are unknown. In this paper, the practical methods to obtain accurate simulation results and the influence of different modeling methods on the accuracy of the finite element model under the specific density gradient are shown. At the same time, in order to enhance the comparison of the simulation results of each structure, under the premise of ensuring the simulation accuracy, the same setting of the foam aluminum vertebral body model with different cross-section shape is carried out in this paper. By comparing the experimental and simulation analysis of different structures, it is found that under the uniaxial quasi-static compression condition, the deformation mode and the energy absorption performance evaluation parameters are analyzed. The shape of section has little effect on the energy absorption performance of foamed aluminum vertebrae and foamed aluminum filled conical thin-walled structure. In addition, the energy absorption capacity of aluminum foam filled conical thin-walled structure is better than that of compression foam aluminum vertebra and thin-walled conical structure. The finite element model of foam aluminum vertebrae with density change is found. When simulating the density distribution of foam aluminum vertebrae, it is necessary to consider the sample size and density change gradient of foam aluminum calibration test and the geometric dimension of foam aluminum vertebral sample.
【學(xué)位授予單位】：湖南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TG146.21;TB383.4
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 楊哲;楊永順;虞跨海;梁斌;康興國;;閉孔泡沫鋁壓縮行為的有限元仿真[J];兵器材料科學(xué)與工程;2013年05期
2 王展光;蔡萍;黃小民;龔昕;;閉孔泡沫鋁合金的力學(xué)性能和吸能能力[J];熱加工工藝;2011年08期
3 王永剛;王春雷;;結(jié)構(gòu)特征參數(shù)和應(yīng)變速率對(duì)泡沫鋁壓縮力學(xué)性能的影響[J];兵工學(xué)報(bào);2011年01期
4 馬鳴圖;易紅亮;路洪洲;萬鑫銘;;論汽車輕量化[J];中國工程科學(xué);2009年09期
5 王智文;;汽車輕量化技術(shù)發(fā)展現(xiàn)狀初探[J];汽車工藝與材料;2009年02期
6 龍江啟;蘭鳳崇;陳吉清;;車身輕量化與鋼鋁一體化結(jié)構(gòu)新技術(shù)的研究進(jìn)展[J];機(jī)械工程學(xué)報(bào);2008年06期
7 杜明義;;用鋁合金材料實(shí)現(xiàn)汽車輕量化[J];輕合金加工技術(shù);2007年02期
8 田杰;胡時(shí)勝;;基體性能對(duì)泡沫鋁力學(xué)行為的影響[J];工程力學(xué);2006年08期
9 李秀芬;雷躍峰;;電動(dòng)汽車關(guān)鍵技術(shù)發(fā)展綜述[J];上海汽車;2006年01期
10 姜斌,趙乃勤;泡沫鋁的制備方法及應(yīng)用進(jìn)展[J];金屬熱處理;2005年06期
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