基于ls-dyna的汽車前縱梁碰撞.doc
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基于ls-dyna的汽車前縱梁碰撞,摘 要近年來由交通事故引起的傷亡人數(shù)不斷增加使得汽車廠家和消費(fèi)者對(duì)汽車安全問題的重視程度越來越高。隨著消費(fèi)者的安全觀念日益增強(qiáng)，汽車廠家在汽車的設(shè)計(jì)和研發(fā)方面也將安全放在了非常重要的位置。因此，汽車安全已成為當(dāng)今汽車工程領(lǐng)域亟待完善的研究領(lǐng)域,并且得到了社會(huì)的高度關(guān)注。由于實(shí)車碰撞試驗(yàn)受到時(shí)間長和費(fèi)用高等限制，一般只做...
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摘 要
近年來由交通事故引起的傷亡人數(shù)不斷增加使得汽車廠家和消費(fèi)者對(duì)汽車安全問題的重視程度越來越高。隨著消費(fèi)者的安全觀念日益增強(qiáng)，汽車廠家在汽車的設(shè)計(jì)和研發(fā)方面也將安全放在了非常重要的位置。因此，汽車安全已成為當(dāng)今汽車工程領(lǐng)域亟待完善的研究領(lǐng)域,并且得到了社會(huì)的高度關(guān)注。
由于實(shí)車碰撞試驗(yàn)受到時(shí)間長和費(fèi)用高等限制，一般只做少量的驗(yàn)證性試驗(yàn)。在實(shí)際產(chǎn)品設(shè)計(jì)中，大量采用有限元分析的方法來代替碰撞試驗(yàn)，并且有研究結(jié)果表明，利用非線性動(dòng)力學(xué)分析軟件LA-DYNA進(jìn)行碰撞模擬仿真與實(shí)車碰撞試驗(yàn)的結(jié)果吻合良好，可以有效地替代實(shí)車碰撞試驗(yàn)進(jìn)行碰撞分析。
汽車發(fā)生正面碰撞時(shí),主要由車身前部的塑性變形來吸收碰撞能量,其中起重要作用的是前縱梁，70 %以上的汽車碰撞能量由前縱梁吸收才能保證駕駛室盡可能完整。 理想的前縱梁設(shè)計(jì)應(yīng)該能夠充分利用前縱梁的塑性變形來吸收汽車碰撞中的大部分能量。汽車前縱梁通?？梢院喕癁楸”诮Y(jié)構(gòu), 因此，研究薄壁結(jié)構(gòu)的碰撞變形吸能特性在汽車前縱梁設(shè)計(jì)中具有重要的意義。
為了使汽車前縱梁在碰撞過程中能夠吸收更多的能量， 本文主要研究不同焊點(diǎn)間距、板厚和材料特性等偏差的汽車前縱梁的碰撞吸能特性，綜合考慮了全面碰撞和偏置40%碰撞前縱梁的綜合吸能特性，并且針對(duì)前縱梁的不同截面形狀、板厚、焊點(diǎn)間距、焊點(diǎn)直徑和偏轉(zhuǎn)角度等設(shè)計(jì)變量，建立了前縱梁碰撞的有限元分析模型，并利用有限元軟件LS-DYNA和響應(yīng)曲面優(yōu)化算法，進(jìn)行了碰撞模擬仿真和優(yōu)化設(shè)計(jì)，從而得出了碰撞吸能特性最優(yōu)的汽車前縱梁。
關(guān)鍵詞 汽車設(shè)計(jì)；前縱梁；碰撞分析；優(yōu)化設(shè)計(jì)；響應(yīng)曲面法
Abstract
In recent years, the rising number of people caused by traffic accident makes car’s manufacturers and consumers pay much attention to safety problem. With the growing of consumer’s security concept, automobile manufacturers will also put the security in an important position during design. Therefore, automobile safety has become an important research field of automotive engineering, and has gotten the much attention of the society.
Because the real crash test takes longer time and higher cost, generally only a little confirmatory test. In the practical product design, using a large number of finite element analysis method to replace the crash test, and the results show that, by using the nonlinear dynamic analysis software LA-DYNA collision simulation and real crash test results are agreement, it can effectively substitute the real car test collision analysis.
When the car has a frontal crash, the plastic deformation of the front body will absorb most of collision energy, and the front side member play an important role in the process. In order to ensure the cab as complete as possible, more than 70% of collision energy must be absorbed by front side member. The ideal front side member design should make the front side member absorb most of the energy in the vehicle collision, reducing its impact on the human body injury. To study the relationship between the structure and deformation, the front side member can be simplified into a thin shell element, so as to finish the security design of front side member. Therefore, the study of thin wall front side member energy absorbing characteristics has important significance to design of front side member.
In order to make the car front side member absorb more energy in colliding process, this paper have studied energy absorption characteristics base on different spot spacing deviation, plate thickness, material characteristics and so on, considering the overall and offset 40% collision energy absorbing characteristics of the front side member, and finished optimum design of the front side member base on the design parameters of the front side member, such as different cross-section shapes, thickness, spot weld pitch, spot diameter and collision direction deviation by using LS-DYNA and the response surface optimization, thus obtains the front side member being the best energy absorbing characteristics.
Key words vehicle design; front side member; impact analysis; optimization; response surface method
目 錄
摘 要 I
ABSTRACT II
第1章 緒論 1
1.1 課題來源和背景 1
1.2 汽車碰撞研究方法 3
1.2.1 試驗(yàn)法 ………………………………………………………………………3
1.2.2 有限元法 ……………………………………………………………………3
1.3 汽車碰撞國內(nèi)外研究現(xiàn)狀 4
1.3.1 國外研究現(xiàn)狀 ……………………………………………………………….4
1.3.2 國內(nèi)研究現(xiàn)狀 5
1.4 本課題的研究目的和內(nèi)容 7
1.4.1 本課題的研究目的 7
1.4.2 本課題的研究內(nèi)容 7
1.4.3 本文結(jié)構(gòu) 8
1.5 本章小結(jié) 9
第2章 基于不同焊點(diǎn)間距及各類誤差的汽車前縱梁碰撞仿真分析 10
2.1 汽車前縱梁碰撞模型的建立 10
2.1.1 建立網(wǎng)格模型 10
2.1.2 添加載荷和約束 12
2.2 碰撞過程 14
2.3 結(jié)果分析 15
2.4 本章小結(jié) 19
第3章 基于不同截面汽車前縱梁碰撞性能比較 20
3.1 不同截面汽車前縱梁簡化模型 20
3.2 結(jié)果分析 23
3.3 本章小結(jié) 31
第4章 保險(xiǎn)杠和前縱梁組合部件的碰撞仿真分析 32
4.1 全面碰撞仿真模型的建立 32
4.2 各種截面前縱梁薄壁機(jī)構(gòu)有限元模型的全面碰撞過程仿真 34
4.3 全面碰撞結(jié)果分析 37
4.4 汽車偏置40%碰撞前縱梁仿真分析 37
4.4.1 不同截面前縱梁偏置4..
近年來由交通事故引起的傷亡人數(shù)不斷增加使得汽車廠家和消費(fèi)者對(duì)汽車安全問題的重視程度越來越高。隨著消費(fèi)者的安全觀念日益增強(qiáng)，汽車廠家在汽車的設(shè)計(jì)和研發(fā)方面也將安全放在了非常重要的位置。因此，汽車安全已成為當(dāng)今汽車工程領(lǐng)域亟待完善的研究領(lǐng)域,并且得到了社會(huì)的高度關(guān)注。
由于實(shí)車碰撞試驗(yàn)受到時(shí)間長和費(fèi)用高等限制，一般只做少量的驗(yàn)證性試驗(yàn)。在實(shí)際產(chǎn)品設(shè)計(jì)中，大量采用有限元分析的方法來代替碰撞試驗(yàn)，并且有研究結(jié)果表明，利用非線性動(dòng)力學(xué)分析軟件LA-DYNA進(jìn)行碰撞模擬仿真與實(shí)車碰撞試驗(yàn)的結(jié)果吻合良好，可以有效地替代實(shí)車碰撞試驗(yàn)進(jìn)行碰撞分析。
汽車發(fā)生正面碰撞時(shí),主要由車身前部的塑性變形來吸收碰撞能量,其中起重要作用的是前縱梁，70 %以上的汽車碰撞能量由前縱梁吸收才能保證駕駛室盡可能完整。 理想的前縱梁設(shè)計(jì)應(yīng)該能夠充分利用前縱梁的塑性變形來吸收汽車碰撞中的大部分能量。汽車前縱梁通?？梢院喕癁楸”诮Y(jié)構(gòu), 因此，研究薄壁結(jié)構(gòu)的碰撞變形吸能特性在汽車前縱梁設(shè)計(jì)中具有重要的意義。
為了使汽車前縱梁在碰撞過程中能夠吸收更多的能量， 本文主要研究不同焊點(diǎn)間距、板厚和材料特性等偏差的汽車前縱梁的碰撞吸能特性，綜合考慮了全面碰撞和偏置40%碰撞前縱梁的綜合吸能特性，并且針對(duì)前縱梁的不同截面形狀、板厚、焊點(diǎn)間距、焊點(diǎn)直徑和偏轉(zhuǎn)角度等設(shè)計(jì)變量，建立了前縱梁碰撞的有限元分析模型，并利用有限元軟件LS-DYNA和響應(yīng)曲面優(yōu)化算法，進(jìn)行了碰撞模擬仿真和優(yōu)化設(shè)計(jì)，從而得出了碰撞吸能特性最優(yōu)的汽車前縱梁。
關(guān)鍵詞 汽車設(shè)計(jì)；前縱梁；碰撞分析；優(yōu)化設(shè)計(jì)；響應(yīng)曲面法
Abstract
In recent years, the rising number of people caused by traffic accident makes car’s manufacturers and consumers pay much attention to safety problem. With the growing of consumer’s security concept, automobile manufacturers will also put the security in an important position during design. Therefore, automobile safety has become an important research field of automotive engineering, and has gotten the much attention of the society.
Because the real crash test takes longer time and higher cost, generally only a little confirmatory test. In the practical product design, using a large number of finite element analysis method to replace the crash test, and the results show that, by using the nonlinear dynamic analysis software LA-DYNA collision simulation and real crash test results are agreement, it can effectively substitute the real car test collision analysis.
When the car has a frontal crash, the plastic deformation of the front body will absorb most of collision energy, and the front side member play an important role in the process. In order to ensure the cab as complete as possible, more than 70% of collision energy must be absorbed by front side member. The ideal front side member design should make the front side member absorb most of the energy in the vehicle collision, reducing its impact on the human body injury. To study the relationship between the structure and deformation, the front side member can be simplified into a thin shell element, so as to finish the security design of front side member. Therefore, the study of thin wall front side member energy absorbing characteristics has important significance to design of front side member.
In order to make the car front side member absorb more energy in colliding process, this paper have studied energy absorption characteristics base on different spot spacing deviation, plate thickness, material characteristics and so on, considering the overall and offset 40% collision energy absorbing characteristics of the front side member, and finished optimum design of the front side member base on the design parameters of the front side member, such as different cross-section shapes, thickness, spot weld pitch, spot diameter and collision direction deviation by using LS-DYNA and the response surface optimization, thus obtains the front side member being the best energy absorbing characteristics.
Key words vehicle design; front side member; impact analysis; optimization; response surface method
目 錄
摘 要 I
ABSTRACT II
第1章 緒論 1
1.1 課題來源和背景 1
1.2 汽車碰撞研究方法 3
1.2.1 試驗(yàn)法 ………………………………………………………………………3
1.2.2 有限元法 ……………………………………………………………………3
1.3 汽車碰撞國內(nèi)外研究現(xiàn)狀 4
1.3.1 國外研究現(xiàn)狀 ……………………………………………………………….4
1.3.2 國內(nèi)研究現(xiàn)狀 5
1.4 本課題的研究目的和內(nèi)容 7
1.4.1 本課題的研究目的 7
1.4.2 本課題的研究內(nèi)容 7
1.4.3 本文結(jié)構(gòu) 8
1.5 本章小結(jié) 9
第2章 基于不同焊點(diǎn)間距及各類誤差的汽車前縱梁碰撞仿真分析 10
2.1 汽車前縱梁碰撞模型的建立 10
2.1.1 建立網(wǎng)格模型 10
2.1.2 添加載荷和約束 12
2.2 碰撞過程 14
2.3 結(jié)果分析 15
2.4 本章小結(jié) 19
第3章 基于不同截面汽車前縱梁碰撞性能比較 20
3.1 不同截面汽車前縱梁簡化模型 20
3.2 結(jié)果分析 23
3.3 本章小結(jié) 31
第4章 保險(xiǎn)杠和前縱梁組合部件的碰撞仿真分析 32
4.1 全面碰撞仿真模型的建立 32
4.2 各種截面前縱梁薄壁機(jī)構(gòu)有限元模型的全面碰撞過程仿真 34
4.3 全面碰撞結(jié)果分析 37
4.4 汽車偏置40%碰撞前縱梁仿真分析 37
4.4.1 不同截面前縱梁偏置4..
