本文選題：有限元法 + 蓄電池　； 參考：《哈爾濱工業(yè)大學(xué)》2014年碩士論文

【摘要】：良好的汽車被動(dòng)安全性能夠在汽車碰撞事故中對(duì)汽車本身和乘員起到有效的保護(hù)作用。電動(dòng)汽車的被動(dòng)安全性設(shè)計(jì)可以借鑒傳統(tǒng)燃油汽車,但也有自己的特點(diǎn):蓄電池作為電動(dòng)汽車重要的部件,是電動(dòng)汽車被動(dòng)安全必須考慮的環(huán)節(jié)。本文首先探討了有限元方法求解沖擊動(dòng)力學(xué)問題的關(guān)鍵理論,為高效的網(wǎng)格劃分提供了理論依據(jù)。研究?jī)?nèi)容包括沖擊問題求解控制方程的數(shù)值求解形式、接觸非線性、材料在沖擊碰撞問題中的本構(gòu)模型等問題。在本文的具體仿真中,對(duì)焊點(diǎn)模擬、顯式算法的步長(zhǎng)控制、單元選擇、沙漏控制等問題也進(jìn)行了探討。本文著重建立了高效的整車有限元模型,用于進(jìn)一步的正面碰撞仿真分析。首先,我們通過對(duì)純電動(dòng)汽車白車身進(jìn)行力學(xué)簡(jiǎn)化,重點(diǎn)考慮車身前部吸能結(jié)構(gòu)和碰撞力傳遞路徑,建立了電動(dòng)汽車整車模型。然后,通過單元類型選擇,單元尺寸和形狀控制,焊點(diǎn)仿真定義,接觸類型定義等工作建立了整車有限元模型。整車碰撞仿真時(shí)間被控制在了一小時(shí)以內(nèi)。最后,按照中國(guó)新車評(píng)價(jià)規(guī)程(C-NCAP)中正面100%重疊的剛性墻碰撞試驗(yàn)工況,對(duì)模型進(jìn)行了碰撞仿真。最終得出了與試驗(yàn)數(shù)據(jù)較為吻合的仿真結(jié)果數(shù)據(jù),驗(yàn)證了整車有限元模型的有效性�；谟行У恼囉邢拊Ｐ�,本文進(jìn)一步研究了蓄電池在汽車碰撞過程中的力學(xué)安全性問題。一方面,我們重新設(shè)計(jì)了蓄電池架結(jié)構(gòu):通過增加蓄電池架斜拉桿的方法優(yōu)化蓄電池架應(yīng)力分布,有效限制了蓄電池在汽車碰撞過程中的翻滾和位移。另一方面,我們將熱成型鋼應(yīng)用于前縱梁擴(kuò)展部分,有效防止了結(jié)構(gòu)在汽車碰撞過程中過大的壓潰和彎曲變形。仿真結(jié)果顯示:蓄電池的最大加速度和平均加速度大幅度減小,蓄電池對(duì)駕駛艙的侵入量減小為零,并且避免了嚴(yán)重的二次碰撞的發(fā)生。研究表明:新的設(shè)計(jì)提高了蓄電池在汽車碰撞事故中的力學(xué)安全性。
[Abstract]:Good passive safety can protect the vehicle itself and occupants effectively. Passive safety design of electric vehicles can draw lessons from traditional fuel vehicles, but also has its own characteristics: batteries as an important part of electric vehicles, is the passive safety of electric vehicles must be considered. In this paper, the key theory of finite element method for solving impact dynamics problems is discussed, which provides a theoretical basis for efficient mesh generation. The research contents include the numerical solution of the governing equation, the contact nonlinearity, the constitutive model of the material in the impact problem and so on. In this paper, some problems such as solder joint simulation, step size control of explicit algorithm, unit selection and hourglass control are also discussed. In this paper, an efficient finite element model is established for further frontal impact simulation. First of all, through the mechanical simplification of the pure electric vehicle's white body, focusing on the front energy absorption structure and the collision force transfer path, the model of the electric vehicle is established. Then, the finite element model of the vehicle is established through the selection of element type, the control of element size and shape, the definition of solder joint simulation and the definition of contact type. The vehicle crash simulation time was controlled within an hour. Finally, according to the 100% overlap rigid wall crash test conditions in C-NCAP, the impact simulation of the model is carried out. Finally, the simulation results are obtained, which are in good agreement with the test data, and the validity of the finite element model of the whole vehicle is verified. Based on the effective finite element model of vehicle, the mechanical safety of battery during vehicle collision is further studied in this paper. On the one hand, we redesigned the storage battery structure: by increasing the oblique pull bar of the battery frame, the stress distribution of the storage battery is optimized, which effectively limits the rolling and displacement of the battery during the collision process. On the other hand, the hot forming steel is applied to the extension of the front longitudinal beam, which effectively prevents the excessive crushing and bending deformation of the structure during the vehicle collision. The simulation results show that the maximum acceleration and the average acceleration of the battery are greatly reduced, and the intrusion of the battery to the cockpit is reduced to zero, and the serious secondary collision is avoided. The results show that the new design improves the mechanical safety of batteries in vehicle crash.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：U467.14;TM912

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本文編號(hào)：1873979