發(fā)布時(shí)間：2019-05-15 02:15

【摘要】：伴隨著人類社會(huì)的快速發(fā)展,汽車也承擔(dān)起了越來(lái)越多的社會(huì)責(zé)任,節(jié)能、排放、安全相關(guān)的法規(guī)越來(lái)越嚴(yán)格,輕量化技術(shù)是滿足上述三個(gè)法規(guī)的有效方法,采用高強(qiáng)度鋼板不僅可以達(dá)到輕量化而且能滿足碰撞安全性。本文主要以高強(qiáng)度鋼板為研究對(duì)象,主要工作如下:1)以典型熱成形零件B柱加強(qiáng)板為例,采用數(shù)值模擬的方法對(duì)熱成形過(guò)程進(jìn)行了研究。通過(guò)熱-力相變-耦合概述了成形時(shí)溫度場(chǎng)分布和應(yīng)力場(chǎng)分布規(guī)律;同時(shí)以成形結(jié)束后溫度場(chǎng)的分布是否符合馬氏體的轉(zhuǎn)變溫度,來(lái)判斷熱成形模擬的可靠性。成形結(jié)束后的零件抗拉強(qiáng)度為1456MPa,硬度為479HV,總結(jié)了板料初始加熱溫度、沖壓速度對(duì)成形結(jié)束后溫度場(chǎng)和應(yīng)力場(chǎng)分布的影響,得出了本次B柱加強(qiáng)板熱成形模擬的工藝參數(shù)組合:初始加熱溫度850℃、沖壓速度200mm/s。2)以高強(qiáng)度鋼板成形為例,研究成形歷史對(duì)碰撞仿真精度的影響。以某汽車縱梁內(nèi)板為研究對(duì)象,通過(guò)利用試驗(yàn)設(shè)計(jì)方法和遺傳算法對(duì)成形工藝參數(shù)進(jìn)行優(yōu)化求解,通過(guò)利用result mapper工具將成形模擬結(jié)果映射到碰撞模型中。以碰撞力和吸能值為評(píng)價(jià)指標(biāo),分析成形后零件的厚度分布、塑性應(yīng)變分布對(duì)碰撞仿真仿真精度的影響。結(jié)果表明:考慮沖壓成形歷史與不考慮成形歷史的吸能誤差達(dá)到11.7%。3)以熱沖壓件為例,研究熱沖壓件在耐撞性方面的應(yīng)用。以不同材料組合的縱梁結(jié)構(gòu)為研究對(duì)象,通過(guò)對(duì)比碰撞后的碰撞力峰值和吸能值,表明在碰撞力峰值增加幅度不大的情況下,其吸能值增加47.8%,相比傳統(tǒng)的通過(guò)利用誘導(dǎo)槽來(lái)增加吸能效果相比,具有明顯的優(yōu)勢(shì)。以B柱為研究對(duì)象,通過(guò)簡(jiǎn)化側(cè)面碰撞模型,引入與整車類似的邊界條件,提高模型的可靠性,通過(guò)減少熱成形B柱的厚度,與原模型進(jìn)行對(duì)比分析,結(jié)果表明在側(cè)碰工況下,侵入量和侵入速度都有改善,同時(shí)質(zhì)量減少0.92kg。
[Abstract]:With the rapid development of human society, cars have also assumed more and more social responsibilities, energy saving, emissions, safety related laws and regulations are becoming more and more strict, lightweight technology is an effective way to meet the above three laws and regulations. The use of high strength steel plate can not only achieve lightweight but also meet the collision safety. In this paper, the high strength steel plate is taken as the research object, the main work is as follows: 1) taking the typical hot forming part B column reinforced plate as an example, the hot forming process is studied by numerical simulation. The distribution of temperature field and stress field during forming is summarized by thermal-mechanical phase transformation-coupling, and the reliability of thermal forming simulation is judged by whether the distribution of temperature field after forming is in accordance with the transformation temperature of martensite. The tensile strength and hardness of the parts after forming are 1456 MPA and 479HV. the effects of initial heating temperature and stamping speed on the distribution of temperature field and stress field after forming are summarized. The process parameter combination of hot forming simulation of B column reinforced sheet is obtained: initial heating temperature 850 鈩，

本文編號(hào)：2477239