单片冲压式汽车下控制臂轻量化优化设计

以某国产车型的焊接型下控制臂为结构轻量化设计对象,综合运用多种优化方法,设计出一款全新的单片冲压型下控制臂.该单片冲压型下控制臂在满足原焊接型下控制臂所需的各项性能的基础上,较原控制臂质量减轻33.3%,轻量化效果显著.     

Optimization Method of the Side Member of the Automobile Seat

Buckling is the primary cause of failure of a sidemember in condition of overloading,so buckling stability should be taken into consideration in the design optimization of side member. On the other hand,lightweight is always a pursuing objective of manufacturer of automobile seat. Thus both the buckling stability and lightweight are considered in the suggested dcsign optimization mcthed of the side member of automobile seats. The method has two design phases. Firstly,the optimal shape of beck curve by using shape optimization was obtained in which the lightweight of the side member was set to be the design objective.Secondly,optimal size and distribution of grooves,on side side member was obtained by topography optimization in which the buckling critical load was set to be the design objective. A typical design example shows that the buckling critical load of the optirnal side member is increased by 25. 98%,and the weight is decreased by 3.7% simultaneously.     

The test device for heat friction coefficient of high strength steel

Using high strength steel and ultra-high strength steel in hot stamping and automobile parts is one of the most important ways of the automobile lightweight,which is the development trend of automobiles currently.In this paper, the development of test device for heat friction coefficient by high strength steel can provide important technical parameters for hot stamping process,making the right selection of equipment types,mold design,technology optimization,and research and development of lubrication medium of press forming.At the same time,the experiments indicate that the instrument has not only accurate test result but also good repeatability.     

轻量化车身用铝合金焊接工装夹具的应用

汽车轻量化能够有效节约油耗和减少废气排量,铝及铝合金材料的特点及性能优势使其成为当今社会汽车轻量化的首选材料。现阶段铝及铝合金材料的连接方式主要为熔化焊,焊接过程中需使用大量的工装夹具辅助生产。焊接工装夹具的设计要符合铝及铝合金熔化焊的工艺特点;夹具定位要简单,最大化实现铝合金焊接的可操作性;同时避免过定位,方便工件装卸。介绍了铝及铝合金的几种典型焊接结构用工装夹具的设计形式,以及终验收时焊接工装夹具可行性试验验证方法。     

轻集料混凝土的断裂能

测定了具有不同强度的轻集料混凝土和普通混凝土的断裂能。比较了轻集料混凝土和普通混凝土的断裂能与抗压强度之间的关系。结果表明，对于给定的强度，轻集料混凝土的断裂能大大低于普通混凝土的断裂能。可以认为混凝土的断裂能可能与抗压强度和容重或与其动弹性模量有关。     

炭纤维复合材料应用于汽车后背门的设计与优化

以某SUV纯电动汽车的后背门为研究对象,利用有限元优化设计方法,以T300牌号炭纤维复合材料代替钢对汽车后背门进行轻量化的重新设计,通过自由尺寸优化、尺寸优化和铺层次序优化三个阶段对后背门炭纤维复合材料的铺层进行优化,并对优化后的炭纤维后背门各项性能参数进行分析。结果表明,相对于原钢制后背门,优化后的炭纤维后背门的扭转刚度、弯曲刚度、侧向刚度、扭转模态频率和弯曲模态频率等性能指标均得到不同程度的提升,且质量由原来的16.70kg降至8.32kg,减重率达到50.2%,轻量化效果明显。     

配置HRB400钢筋陶粒混凝土梁的试验

为了研究配置HRB400钢筋陶粒混凝土梁的力学性能,采用试验方法,完成了6根受弯梁的试验研究。结果表明:陶粒混凝土梁的开裂荷载大于普通混凝土梁的,极限承载荷载则和普通混凝土梁的相差不大,破坏时具有显著的脆性特征;在相同荷载作用下,陶粒混凝土梁的挠度比普通混凝土梁的大,刚度则小于普通混凝土梁的;裂缝宽度比普通混凝土梁的小。纤维的加入明显提高了陶粒混凝土梁的开裂荷载,减小了陶粒混凝土梁的裂缝宽度。     

Forming analysis and application for aluminum alloy material

The increase in car ownership brought about by energy shortages,and environmental crises became more acute.The most effective way to achieve energy saving and emission reduction of car is to improve engine efficiency.In addition to that,lightweight body is the key.Aluminum,magnesium alloy as significant materials of lightweight,and the application amount in the car body is a significant upward trend.However,there is high cost of material,with immature applied technology and a series of bottleneck problems.All of them affect general application of lightweight materials. This paper focuses on forming process issues for aluminum,magnesium alloy and the solutions to achieve.     

基于多目标的汽车前端框架拓扑优化

针对汽车前端框架的结构和工况特点,建立基于Hyperworks的有限元模型,运用带权重的折衷规划法定义综合目标函数来进行多目标拓扑优化,通过灰色关联法和层次分析法分别计算静态多工况下柔度的权重以及动态低阶频率的权重.结果表明:优化后的汽车前端框架最大变形、最大应力分别降低了21.67％、34.39％;第一阶模态提高了1...     

轻质结构发动机罩设计研究

以汽车发动机罩为例，结合材料特性、生产工艺、连接工艺等方面因素，设计四种不同材料发动机罩结构方案．采用拓扑方法优化、改进结构，并通过有限元结构模拟计算，比较分析并评价各方案．选择其中综合性能优势最为显著的复合材料结构方案进行试制并试验．通过对比模拟计算结果和试验结果，验证了复合材料结构方案的性能优越性．在轻量化方法、设计试验规范、选材与结构等方面，为汽车车身的轻量化研究探索了一条技术路线。     

聚合物乳液对纤维增强轻集料混凝土力学性能的影响

研究了聚合物乳液的掺入对纤维增强轻集料混凝土的强度与弯曲韧性的影响,结果表明,掺入聚合物乳液虽然在一定程度上降低了抗压强度,但可以显著提高轻集料混凝土的劈裂抗拉强度和抗折强度.聚合物乳液的掺入可以有效提高纤维增强轻集料混凝土的韧性、降低其脆性,韧度系数最高可提高32倍.研究发现,聚合物乳液对钢纤维增强轻集料混凝土的强度和韧性的改善效果优于对聚乙烯纤维增强轻集料混凝土的改善效果.     

轻集料颗粒群特征对混凝土力学性能的影响

运用数字图像处理技术研究轻集料的颗粒群特征,采用多种参数表征轻集料颗粒群的粒度和粒形特征.在此基础上,通过灰色关联分析,研究轻集料颗粒群特征对混凝土力学性能的影响.结果表明,当轻集料颗粒群比表面积在520 m2·m-3以上并且颗粒长宽比低于1.34时,所配制的轻集料混凝土能同时达到较高的抗压强度和抗折强度.这为高性能轻集料混凝土的配制提供了依据.     

轻型木结构外墙热工计算方法及空调负荷分析

针对一种典型轻型木结构外墙,在综合分析几种常用简化热工计算方法基础上,提出了一种改进计算方法,并与实测值进行了对比,说明改进后的简化方法准确性较好.然后运用能耗软件Energyplus对重庆某住宅卧室进行典型日的冷热负荷计算,对比单位面积的轻型木结构、节能50%及节能65%典型砖混结构外墙得热引起的空调负荷.结果表明:轻型木结构外墙所引起的冷热负荷最小,日平均冷热负荷约为节能65%砖混结构外墙的55%,但夏季隔热性能比节能65%砖混结构外墙差,负荷波动大,提高轻型木结构墙体在夏季的隔热性能是改善其热工性能的关键.     

全地形车车架结构灵敏度分析及轻量化设计

为了快速有效地降低某全地形车生产成本,利用有限元前处理软件HyperMesh建立了某全地形车车架结构的有限元模型,运用Optistruct求解器计算其自由模态并与已有的试验结果进行对比,验证了该模型的正确性。通过Optistruct分析车架在多种工况下的应力分布和变形情况,计算其疲劳寿命并进行灵敏度分析,提出该车架结构轻量化方案,并分析优化后车架结构强度及疲劳寿命,证明了此轻量化方案具有一定的有效性。轻量化车架结构减轻了6.606 3kg,表明通过灵敏度分析能够提高结构优化效率以及轻量化效果。     

浇注成型法制磷石膏轻质墙体砖的研究

研究磷石膏的预处理方法和浇注成型法制备磷石膏轻质墙体砖。通过实验考察了磷石膏预处理方式和成型方法对砖强度的影响,实验结果表明,采用煅烧,石灰中和,或者煅烧加石灰中和的方法处理后的磷石膏都能够用作制备磷石膏轻质墙体砖。采用石灰中和法处理磷石膏,浇注法成型,蒸养和自然养护的制砖工艺能够制备出满足JC422-91《非烧结普通粘土砖》标准要求的磷石膏轻质墙体砖。     

结构用橡胶轻集料混凝土的性能实验研究

针对橡胶轻集料混凝土的基本力学性能进行了试验研究,通过对不同橡胶集料掺量、水泥用量和不同矿物掺和料的轻集料混凝土基本性能的研究,结果表明在普通轻集料混凝土中掺入一定质量的橡胶微粒可以有效的改善轻集料在混凝土中的分布状况,通过调整橡胶集料的含量和加入一定质量的矿物掺和料可以配制出和易性、坍落度均优且强度满足CL30的结构用橡胶轻集料混凝土.     

1t固定式矿车车架的轻量化设计

针对矿车零部件安全储备过高、运输中无用功耗过大的问题,运用轻量化的思想,应用ANSYS有限元分析软件对使用量最大的1 t固定式矿车的车架,进行了典型工况下的应力和变形分析,提出了结构件替换、局部加强以及碰头座板厚度减薄的轻量化组合方案,即采用局部加强的8#普通槽钢代替原异型槽钢做车架的纵梁,同时减薄碰头座板厚度。仿真结果表明:在满足强度和刚度要求且碰头有效发挥作用的基础上,可实现车架减重28.6 kg,为矿车轻量化提供了参考依据。     

一种增强的极轻量RFID安全认证协议研究

由于低成本的RFID标签运算能力有限,它无法支持复杂的密码算法,因此设计轻量级的安全协议尤为重要.URAP是一种基于简单位运算的极轻量级安全协议,兼有安全与隐私保护.本文详细分析了URAP协议的安全性问题,并对它做出了改进,通过增加标签端的随机数R1与阅读器的识别码RID来保护信息的传送,避免了拒绝服务攻击、完全泄露攻击与追踪攻击,有效地提高了RFID应用的安全性.     

Simulation about hot stamping of ultra high strength steel on the basis of lightweight technology

With the development of automobile lightweight,it is very necessary to apply the ultra-high strength steel parts manufactured by hot stamping,which offers the possibility to reduce the weight of automobiles and maintain the safety requirement.In order to complete hot stamping,it is important to design the structure of parts reasonably,which is related with reasonable matching of strength.The objective of this paper is to guide the design of parts manufactured by hot stamping and find the forming technical requirements of vehicle performance.Through experiments,the paper obtains the stress and strain curves at different deformation temperatures and strain rates.Based on experimental data, the constitutive relationship model is established which can reflect the deformation capacity of ultra-high strength steel during the process of hot stamping.Combined with finite element simulation results of hot stamping by commercial software AUTOFORM,transfer path of load and matching law of strength,the paper determines the design criteria and forming technical requirements of parts manufactured by hot stamping.At the same time,the impact performance of front cross member internal plate is taken into consideration.     

Influence of polymer addition on performance and mechanical properties of lightweight aggregate concrete

The influence of polymer addition on microstructure, performance and mechanical properties of lightweight aggregate concrete was investigated. It was found that the addition of polymer improved the performance and mechanical properties of lightweight aggregate concrete. It was ascertained that the modification of microstructural uniformity and densification with the addition of polymer is responsible for the enhancement of mechanical properties.With respect to compressive strength and bending strength, the lightweight aggregate concrete added with 13% ethylene-acetate ethylene interpolymer ( EVA ) exhibits preferred mechanical properties.