微型客车正面碰撞计算机仿真时问与精度研究

结合国内软硬件资源条件 ,着重探讨了汽车碰撞计算机仿真分析所面临的关键技术难点和汽车各部件正面碰撞的建模策略 ,模拟结果在整车及主要吸能结构的变形模式、典型测点的加速度时间历程等方面均与实车碰撞试验结果吻合良好。     

基于改进BP-GA方法的FPSO舷侧结构耐撞性能优化设计

基于遗传算法和ABAQUS参数化有限元仿真技术,对传统的BP-GA优化方法进行改进,并采用改进的BP-GA方法对浮式生产储油卸油装置(FPSO)舷侧结构的耐撞性能进行优化,以验证其可行性和准确性。结果表明,与传统的BP神经网络相比,经遗传算法优化的BP神经网络具有更高的预测精度和更强的泛化能力;改进的BP-GA优化方法可在结构减重的基础上进一步提高结构的耐撞性能,能较好地适用于复杂的FPSO舷侧结构耐撞性优化设计。采用的优化方法具有通用性,可为抗爆性能的优化设计提供参考。     

Extension of the super-elements method to the analysis of a jacket impacted by a ship

The aim of this paper is to present a simplified analytical method for estimating the crushing resistance of an oblique cylinder impacted by the stem of a striking ship. The collision angle of the vessel is arbitrary, i.e. oblique collisions are also considered in this article. The two extremities of the tube are assumed to be clamped. These developments are intended to be used for evaluating the crashworthiness of an offshore wind turbines jacket. To achieve this goal, closed-form expressions are first derived for the particular situations of a horizontal and a vertical cylinder by applying the upper-bound method. An interpolation formula is then proposed to get the resistance opposed by the tube for any inclination angle. In order to validate these theoretical developments, some comparisons are made with the results of numerical simulations. These latter are performed using the finite elements software LS-DYNA. In almost all cases, the analytical prediction of the resistance is found to be in quite good agreement with the numerical ones. Finally, another comparison is made by simulating an OSV collision with a full jacket. In this case, the theoretical model is found to be insufficient for large impact energies and points out the need of further research.     

相容性车身及行人假人

近年来,随着各国正面碰撞试验法规的实施,汽车的碰撞安全性能有了显著的提高。然而,由于在碰撞中存在两车辆的“质量”、“刚度”和“结构”并不相同的情况,当大车与小车发生正面碰撞时,往往会导致小车乘员舱产生比较大的变形,因此提高小车的自我保护性能就显得尤为重要。为了达到正面碰撞中两车的相容性,本文介绍了一种新型车身结构在实车中的应用情况,以及其提升车辆安全性能的作用,并简要介绍了本田汽车公司在行人保护方面所做的研究。     

LPG船舷侧结构的碰撞性能研究

研究了LPG船舷侧结构碰撞损伤过程和多种构件的抗撞作用，通过分析发现，LPG船的舷侧耐撞力远远低于同吨位的常规单壳船。LPG船的强肋骨在抵抗碰撞中起主要作用，由此提出提高常规LPG船舷侧结构提高耐撞力的最佳途径。     

车身结构耐撞性的概念设计仿真

车身结构耐撞性的概念设计是由车辆乘员伤害指标确定出整车碰撞波形（正面碰撞），根据波形将车身结构性能分解参数化设计，文章从CAE建模角度。探讨比较了建立车身概念设计模型的各种主要方法工具，包括LMS模型、有限元Beam—element模型和多体MadymoFrame模型。表明各模型的建模特点和基本方法主要取决于结构刚度特性和惯性特性的提取与参数化。指出三维模型在概念设计阶段具有适用性和局限性。     

基于正交试验设计的薄壁结构耐撞性优化设计

为了提高薄壁结构的耐撞性能,本文提出了一种高效的设计方法:。利用二次回归正交组合试验设计方案来选取设计点,在设计点处用有限元法代替传统试验来获取试验数据。然后通过最小二乘法建立了刚性墙最大位移、撞击力峰值和总质量的高精度响应面。综合考虑厚度的变化范围、安全性和轻量化要求,运用可行方向法对建立的响应面进行优化计算,得到了一组最优值。结果:表明本文的设计方法:具有很高的精度和计算效率,实现了提高薄壁结构耐撞性的目的:。同时也为车身复杂结构(如前纵梁、吸能盒等)的耐撞性设计提供理论依据和参考方法:。     

A simplified analytical method to estimate the resistance of plane lock gates impacted by river barges

This paper presents a simplified analytical method to evaluate the resistance of a single plating lock gate impacted by a river barge. The approach is based on the assumption that the gate behavior may be divided into two successive phases. At the beginning of the collision, local crushing of some structural elements occurs concomitantly with small overall elastic motion of the entire gate. Then, when the penetration of the barge into the gate becomes important, a global plastic mechanism develops over the entire structure. In addition to the membrane and bending deformations occurring classically in such collisions, the particular flat shape of the striking barge bow leads to shear deformations near the gate edges. For all these deformation modes, closed-form expressions of the gate resistance are derived for both local and global deformation phases by applying the upper-bound method. These analytical developments are then validated through comparisons with numerical solutions obtained from non-linear finite-element simulations.     

列车多体耦合撞击分析

设计了耐冲击吸能车体,其前端司机室控制台前端和尾端为塑性大变形区域,中间载客区为弹性小变形区域。建立轻轨列车的等效简化模型。对实际模型和简化模型在同样工况下进行了撞击计算,结果显示等效模型和简化模型的变形过程相似,力—位移曲线也基本相同。在简化的轻轨车模型基础上,模拟6辆编组的轻轨列车以25km.h-1速度撞击一列静止的轻轨列车,得到各辆车的动力学响应。计算结果显示,车辆与车辆之间发生了多体耦合撞击,每辆车都产生了塑性变形,其中头车前端塑性变形较大。     

基于全耦合分析技术的折叠式夹层板船体结构碰撞性能研究

船舶碰撞事故往往会带来灾难性的后果,船舶碰撞性能以及耐撞结构设计方面的研究一直受到国内外学者的重视。本文基于全耦合数值仿真分析技术,以一多用途船舷侧结构为研究对象,设计出两种夹层板新式抗冲击舷侧结构,并对原结构和新式结构的碰撞性能进行比较。研究结果表明,新式舷侧结构发生损伤变形的区域较大,参与抵抗撞击的构件增多,损伤变形程度有所降低,且在总重量相当的条件下总吸能有大幅提高,可以有效缓解高能碰撞对结构的危害。