共查询到18条相似文献,搜索用时 437 毫秒
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在翻滚事故中,车辆的主要承载件是车顶及其支承结构。只有这些结构有足够的刚度才能保证翻滚事故中乘员必要的生存空间。我国将颁布顶盖挤压标准,对车顸刚度及检测方法提出要求。本文通过有限元分析法进行预测,物理实验结果表明,该方法是可行的。 相似文献
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通过模拟振动试验方法,研究了发生在混凝土凝结硬化不同阶段的振动对混凝土抗压性能的影响。根据试验结果,初凝前受到振动扰动的混凝土,其早期和后期的抗压强度没有出现下降;初凝至终凝期间的振动,对混凝土的早期和后期抗压强度变化影响不明显。发生在终凝后的振动,振动能量较小时就会造成混凝土的早期抗压强度下降,但对后期强度影响不够明显。 相似文献
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建立某微型客车平台翻滚试验有限元仿真模型,通过对运动姿态、运动参数和部件变形进行对标分析,验证有限元模型的可靠性。根据车辆变形、受力和吸能等试验与仿真结果,确定两根顶盖横梁和左右A柱内板为目标车型在翻滚碰撞过程的关键结构。从车身结构耐撞特性与吸能特性出发,综合考虑生存空间侵入与结构能量吸收的评价指标,利用Opt LHD试验设计、KRG近似模型构建、NAGA-Ⅱ多目标寻优和比例系数取优等方法完成关键结构的优化。优化后关键结构总质量减轻24.78%,结构总吸能减少18.81%,关键构件的平均比吸能提升11.89%。 相似文献
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依照相关标准和法规,对某型校车车身顶部强度进行静态压溃、准静态压溃和整车跌落的仿真研究,系统评价校车车顶结构的抗压强度特性,并对关键承载结构进行改进。 相似文献
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阐述了车身扭转刚度的计算方法和测量方法,探讨了提升车身扭转刚度的方法途径.以某三厢车改款开发两厢车为例,在车身新设计过程中,通过加强载荷传递路径的刚度设计,加强车身关键接头结构的刚度设计,以及加强车身上安装点固定支架与车身上承载梁的集成性设计,实现两厢车在无后隔板的情况下也能达到较高的车身扭转刚度要求,进而证实了车身扭转刚度性能提升方法有效. 相似文献
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《公路交通科技》2020,(9)
为研究玄武岩纤维和粗、细聚丙烯纤维加筋水泥土抗压性能,本研究通过无侧限抗压强度试验,对浸水条件下不同土质、水泥掺量、纤维种类、纤维掺量、纤维长度以及纤维组合方式试件抗压性能进行了研究。结果表明:水泥能够一定程度提高土体无侧限抗压强度,但水泥土试样应力应变曲线峰后下降较快,呈脆性破坏特征;掺入纤维能继续提高水泥土无侧限抗压强度,有效改善水泥土脆性破坏模式并提高水泥土抗开裂性能;玄武岩纤维分散性不良,而粗、细聚丙烯纤维分散性较好,适用于纤维加筋水泥土;纤维掺量和纤维长度对纤维加筋水泥土抗压性能有较大影响,随着纤维掺量的增加,无侧限抗压强度总体呈现先增大后减小规律;对于不同土质和不同纤维种类,纤维长度对纤维加筋水泥土无侧限抗压强度的影响不一。细聚丙烯纤维理想长度和掺量为12 mm和0.8%,粗聚丙烯纤维理想长度和掺量为38 mm和0.8%。相较于单种纤维加筋,粗细聚丙烯纤维混掺加筋对水泥土抗压强度的增强与脆性破坏模式的改善效果更好,粗细混掺聚丙烯纤维加筋水泥土理想组合为38 mm长粗聚丙烯纤维(掺量为0.3%)+12 mm长细聚丙烯纤维(掺量为0.3%)。 相似文献
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Wook-Han Choi Youngmyung Lee Jong-Min Yoon Yong-Ha Han Gyung-Jin Park 《International Journal of Automotive Technology》2018,19(2):291-299
A roof crush test has been utilized to reduce passengers’ injuries from a vehicle rollover. The Federal Motor Vehicle Safety Standards (FMVSS) 216 and the Insurance Institute for Highway Safety (IIHS) perform actual vehicle tests and evaluate the vehicle’s ratings. Nonlinear dynamic response structural optimization can be employed not only for achievement of a high rating but also minimization of the weight. However, the technique needs a huge computation time and cost because many nonlinear dynamic response analyses are required in the time domain. A novel method is proposed for nonlinear dynamic response structural optimization regarding the roof crush test. The process of the proposed method repeats the analysis domain and the design domain until the convergence criteria are satisfied. In the analysis domain, the roof crush test is simulated using a high fidelity model of nonlinear dynamic finite element analysis. In the design domain, a low fidelity model of linear static response structural optimization is utilized with enforced displacements that come from the analysis domain. Correction factors are employed to compensate the differences between a nonlinear dynamic analysis response and a linear static analysis response with enforced displacement. A full-scale vehicle problem is optimized with a constraint on the rigid wall force from the analysis in the design domain. 相似文献
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悬架系统的减振器支架作为连接车架及减振器的零件,在车辆运行过程中,因受到减振器的拉力及压力,经常导致断裂失效,致使减振器无法正常工作。文章以某车型减振器支架的故障断裂为例,采用HyperMesh有限元分析方法对支架进行应力分析,计算结果表明:支架最大应力384MPa,应力最大位置与故障件断裂位置吻合,因此,判断支架因强度不足导致的断裂。针对支架的断裂原因,提出了3种加强改进方案,从应力、重量、成本、整改周期等因素考虑,选择最优的改进方案。整改后的减振器支架3年内售后故障率为0,达到预期效果,整改方案有效。 相似文献
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J. H. Seo E. D. Lee J. W. Lee B. K. Han 《International Journal of Automotive Technology》2016,17(4):665-670
This study reports on the effect of vehicle tumble-home (side body inclination) on roof strength. The steep inclination of the side body of a vehicle increases its roof strength. Comprehensive analysis of the impact of high roof strength driven by the steep inclination on dynamic roof strength in rollover is described. Here, we have developed a numerical model using the ADAMS, which is capable of characterizing both of the static and the dynamic roof strength. According to the FMVSS 216 protocol, we achieve the strength to weight ratio (SWR; static roof strength) by applying loading plates to the roof of a vehicle. The Controlled Rollover Impact System (CRIS) allows us to quantitatively characterize the displacements of the top end of A-pillar and B-pillar, thus determining the dynamic roof strength by comparing the results. We demonstrated that the roof intrusion was one of the most critical causes which lead to injuries of occupants fastening seat belts. Our analysis revealed that the increase of the side body inclination of vehicles enhanced the static roof strength whereas it could not reduce the roof displacement (intrusion) in the dynamic rollover. 相似文献