• 在各行业中涉及到金属连接的部分，焊接是整个生产中非常关键的一环，涉及到的焊接不仅种类多、焊缝多、焊接结构复杂，且大部分焊缝均为多层多道焊，这就导致了在整个焊接过程中，零件的焊接变形难以控制。
• 因此长期以来，对于焊接工艺的改进和优化主要依靠工艺人员的经验和各类工艺试验，一直缺乏一套专业的有效的方法和手段。随着计算机技术的发展和有限元理论的逐渐成熟，焊接模拟仿真技术已经开始成为在焊接工艺优化改进过程中的良好手段和方法。

Seats and head restraints are tested on a sled using a low speed rear-impact dummy. Three dynamic tests are done, representing common accident severities known to cause injuries, together with an assessment of the geometry of the front and rear head restraints.

• 汽车座椅作为乘员和汽车的重要连接纽带,对乘员的安全起到尤为重要的作用。合理的座椅结构设计,能够确保座椅在承受复杂载荷的条件下满足一定的强度要求,能够在保证功能不失效的前提下吸收更多的碰撞能量,能够有效地减轻碰撞过程中乘员的损伤程度。
• 基于某品牌汽车的座椅,运用有限元仿真分析方法,对其安全性能进行研究,主要工作如下: 首先,对座椅的CAD数模进行离散化处理,对骨架、高度调节器及滑轨等零部件进行细致地划分,得到详细的结构模型。根据真实的材料特性确定各零部件的材料及其属性,并选择合理的连接方式保证仿真的精度。 
• 其次,运用Hypermesh和Primer作为前处理器,LS-Dyna、Nastran以及Abaqus为求解器,Hyperview为后处理器。依据国内法规GB15083-2006、GB11550-2009和GB14167-2006以及2021版中国新车评价规程(C-NCAP,China New Car Assessment Program)规定的试验条件设置相关的参数,定义相应的边界条件,建立模态试验、头枕能量吸收性试验、靠背静强度试验、座椅静强度试验、座椅抗惯性试验、安全带固定点强度试验、ISOFIX固定点强度试验、行李箱冲击试验以及鞭打试验的仿真模型。

The Adult Occupant Protection score is determined from frontal impact, side impact and whiplash tests, which are carried out to evaluate the protection of adult driver and passengers offered by the vehicle. 

1-1 Full Width Rigid Barrier-FRB
Cars against a rigid barrier with full overlap at a test speed of 50km/h. A small female frontal impact dummy is seated in the front driver’s seat and in the rear passenger side seat.

1-2 Offset-Deformable Barrier – ODB
In the full-scale test, the car is driven at 64km/h and with 40 percent overlap into a deformable barrier which represents the oncoming vehicle. The test replicates a crash between two cars of the same weight, both travelling at a speed of 50km/h. Two frontal impact dummies representing the average male are seated in the front and child dummies are placed in child restraints in the rear seats.

1-3 Side Mobile Barrier
A deformable barrier is mounted on a trolley and is driven at 50km/h into the side of the stationary test vehicle at right angles. A side impact dummy representing an average male is put in the driver’s seat and child dummies are placed in child restraint systems in the rear.

1-4 Side Pole
A car is propelled sideways at 32km/h against a rigid, narrow pole. The car is placed at right angles to the direction of motion, or as is done from 2015 onwards, at a small angle away from the perpendicular. A single average male side impact dummy is placed in the driver’s seat.

欧洲每年有超过 1,000 名儿童死于交通事故。 几乎有一半的儿童致命事故都是在儿童作为机动车乘员的情况下发生的。
车辆制造商在法律上有义务提供关于在车辆座位上使用儿童约束装置的信息。NCAP会检查不同儿童约束装置的合适程度，同时验证在正面或侧面碰撞事件中推荐的儿童约束装置所提供的保护。
最初，模拟 1 岁半至 3 岁儿童的儿童假人被安放在汽车后排座椅上由汽车制造商推荐的儿童约束装置中。2016 年，试验配置发生了改变，试验改为将模拟 6 至 10 岁儿童的儿童假人安放在防护座椅或坐垫上。
假人的头部运动、颈部承重和胸部加速度是试验过程中的主要测量指标。如果试验指标保持较低水平，并且碰撞过程中假人未从座椅上弹起或不会与车辆内部猛烈撞击，则该车辆将获奖项。这可以确保儿童在碰撞事件中始终受到正确的约束。

The Pedestrian Protection score is determined from tests to the most important vehicle front-end structures such as the bonnet and windshield, the bonnet leading edge and the bumper. In these tests, the potential risk at injuries to pedestrian head, pelvis, upper and lower leg are assessed.

Head impact
Most pedestrian accidents occur within city areas where speeds are moderate. The head, the lower body and the legs are amongst the most frequently injured body regions. To estimate the potential risk of head injury in the event of a vehicle striking an adult or a child, a series of impact tests is carried out at 40 km/h using an adult or child head form impactor. Impact sites are then assessed and the protection offered is rated as good, adequate, marginal, weak or poor.The procedure promotes energy absorbing structures, deformation clearance and deployable protection systems such as pop-up bonnets and external airbags.

Upper Leg Impact
To estimate the potential risk of pelvis and upper leg injuries in the event of a vehicle striking an adult, a series of impact tests is carried out at 40 km/h using an adult upper leg form impactor. Impact sites are then assessed and the protection offered is rated as good, adequate, marginal, weak or poor.The procedure promotes energy absorbing structures and a more forgiving geometry that mitigates injuries.

Lower Leg Impact
To estimate the potential risk of leg injuries in the event of a vehicle striking an adult, a series of impact tests is carried out at 40 km/h using an adult leg form impactor. Impact sites are then assessed and the protection offered is rated as good, adequate, marginal, weak or poor. The procedure promotes energy absorbing structures and a more forgiving geometry that mitigates injuries to the leg.

• 汽车后视镜的CAE有限元仿真分析是验证其结构性能与安全可靠性的关键数字化手段。该过程首先基于三维几何模型，建立包含镜壳、镜托、基座及折叠机构等部件的高精度有限元网格模型，并准确赋予各部件材料属性（如弹性模量、泊松比及屈服强度）。
• 仿真主要涵盖多个核心工况：模拟车辆高速行驶时镜体承受的风压载荷，评估其变形量是否影响视野及支架根部应力是否超限；依据法规要求，模拟镜体在外力作用下的绕轴折叠与回位过程，分析转轴及限位结构的耐久损伤；此外，还包括模态分析以避免与发动机或路面激振频率共振。通过求解计算，可精准预判危险区域应力分布与疲劳寿命。仿真结果不仅指导产品轻量化设计，减少实物试错，更是确保后视镜满足振动耐久、抗冲击及空气动力学性能等强制性标准的核心依据，显著缩短了开发周期并降低了成本。

多学科设计优化是一种充分探索子系统相互作用的复杂系统设计方法论，多学科设计优化最早是由美国国家航空航天 局（National Aeronautics and Space Administration ,NASA）高级研究院、现任美国航空航天学会（American Institute of Aeronautics and Astronautics,AIAA）多学科设计优化技术委员会主席Sobieszczanki-Sobieski提出，是一种探索子系 统相互作用的复杂系统设计方法论。通过探索和利用系统中相互作用的协同机制，利用多目标策略和计算机辅助技术来 设计复杂系统及子系统，可以有效缩短设计周期，获取系统整体最优性能。

• 多体系统动力学是研究多体系统（一般由若干个柔性和刚性物体相互连接所组成）运动规律的科学。多体系统动力学包括多刚 体系统动力学和多柔体系统动力学。虽然经典力学方法原则上可用于建立任意系统的微分方程，但随着系统内分体数和自由度的 增多，以及分体之间约束方式的复杂化，方程的推导过程变得极其繁琐。
• 为适应现代计算技术的飞速发展，要求将传统的经典力 学方法针对多体系统的特点加以发展和补充，从而形成多体系统动力学的新分支。为建立多体系统动力学的数学模型，已经发展 了各种方法，其共同特点是将经典力学原理与现代计算技术结合。这些方法可归纳为两类，即相对坐标方法和绝对坐标方法。
• 多体系统动力学分析涵盖建模和求解两个阶段，其中建模包括从几何模型形成物理模型的物理建模、由物理模型形成数学模型的数 学建模两个过程，求解阶段需要根据求解类型（运动学/动力学、静平衡、特征值分析等）选择相应的求解器进行数值运算和求解。

• “在一处或几处产生永久性累积损伤”经一定循环次数后产生裂纹或突然发生完全断裂的过程。 疲劳寿命的定义为发生疲劳破坏时的载荷循环次数，或从开始受载到发生断裂所经过的时间。即材料或构件疲劳失效时所经受的规定 应力或应变的循环次数，是设计人员和工程技术人员十分关注的课题，也是与广大用户切身相关的问题。