新型双刚圈航空轮胎的仿真研究

以46/17R20航空子午线轮胎和一种新型高性能新概念轮胎——双刚圈航空轮胎为研究对象,利用ABAQUS软件分析静载荷工况下的径向和纵向刚度以及以288 km·h-1初始水平速度的制动过程中胎面受力及接地性能。结果表明:与传统航空轮胎相比,静载荷工况下双刚圈航空轮胎的径向刚度显著提高,纵向刚度略有下降;制动工况下双刚圈航空轮胎胎面等效应力以及径向和纵向接触压力分布规律均明显较优。双刚圈航空轮胎的承载能力、接地性能和制动性能均优于传统航空轮胎,其中外刚圈轴向长度适中的双刚圈航空轮胎的综合性能最优。     

245/70R16轮胎的有限元分析

以Abaqus为平台,采用有限元法对245/70R16轮胎进行分析,研究负荷、外倾角和侧偏角对轮胎整体静力学与动力学性能、温度场与滚动阻力场分布的影响。结果表明:随着负荷的增大,轮胎整体的变形和接地面积增大,接地性能变差,肩部与胎圈部位的应变能密度增大,轮胎的横向刚度略有减小,纵向刚度和径向刚度略有增大,而旋转刚度明显增大,肩部和胎圈最高点的温度升高;随着外倾角的增大,轮胎的滚动温度场与滚动阻力场分布趋向于不对称,滚动阻力和滚动阻力系数均增大。     

制动过程中轿车子午线轮胎的接触力学性能研究

采用室内平板式轮胎试验机模拟轮胎的制动过程,研究轮胎胎面纵向位移线性段长度、纵向刚度、纵向最大摩擦力和垂直合力偏心距,并用串联Voight模型解释轮胎试验过程中的现象.胎面纵向位移线性段长度、纵向刚度、纵向最大摩擦力和垂直合力偏心距均随负荷增大而增大,且负荷的影响大于充气压力.     

基于ABAQUS建模的轮胎接地特性及静态刚度的分析研究

利用ABAQUS软件对三维轮胎接地模型进行建模,模拟了不同充气压力、不同垂直载荷下的轮胎接地情况,并对轮胎的静态刚度进行了分析。结果表明,固定垂直载荷下,随着气压的增大,法向应力最大值由胎冠两侧向胎冠靠拢。标准大气压下,随着载荷的增大,轮胎最大法向应力由胎冠中心向轮胎两侧移动。径向刚度、横向刚度、单位长轴纵向刚度、扭转刚度都与充气压力有关,只有扭转刚度受垂直载荷影响。     

基于纵向力的轮胎模型及参数分析

通过垂直负荷分布修正和滑动摩擦因数参数化,建立轮胎纵向力模型,利用其对轮胎纵向力特性进行分析,并研究各因素对轮胎纵向力的影响。结果表明,随着静摩擦因数的增大,接地胎面完全滑移的滑移率增大,滑移力（Fsx）和附着力（Fax）增大;纵向刚度主要影响峰值前的纵向合力,随着轮胎纵向刚度和接地印痕长度的增大,接地胎面完全滑移的滑移率减小,Fax减小,Fsx增大。     

225/65R17102H公路型轮胎的设计

介绍225/65R17 102H公路型轮胎的设计。胎面花纹设计：采用胎面花纹块精确比例、胎面花纹沟边、胎面花纹深浅钢片、5种单元节距以及宽大的块状肩部花纹设计;结构设计：采用宽大的接地面、加深沟槽和加强的胎体材料设计。通过轮胎有限元仿真分析,轮胎的接地压力分布均匀,接地形状方正。成品轮胎的胎圈强度、高速性能和耐久性能均满足国家标准要求,实车评价其在噪声、乘坐舒适性以及干湿地操控性能方面表现优异。     

下胎侧具有支撑设计的斜交工程机械轮胎的研发

工程机械轮胎．尤其是用于大型推土机和装载机上的工程机械轮胎，由于使用环境恶劣，负荷大，下沉量大．且使用过程中启动和制动频繁、转弯较多，因此．对胎圈的性能和下胎侧支撑性能要求较高。但传统设计的工程机械轮胎由于胎圈和下胎侧设计不尽合理，从而引起下胎侧的支撑性能以及耐刺扎性均不够理想。     

受力轮胎花纹块与胎体变形量测试系统的研究

开发了一种测量在径向力、切向力和侧向力作用下轮胎胎面花纹块变形量和胎体变形量等参数的试验系统。该系统可以在不同条件下进行如下参数的测量 :轮胎胎面花纹块变形量、胎体变形量、轮胎的接地印迹、轮胎下沉量及滚动半径、轮胎与路面的摩擦因数、轮胎径向刚度、侧向刚度和切向及扭转刚度等。该系统为汽车的动态仿真提供更接近实际的轮胎模型及参数数据 ;可以验证轮胎有限元计算结果的精度和误差 ;为轮胎的振动与噪声仿真计算与分析提供了理论依据。重要的是可以通过该系统研究轮胎结构参数与轮胎各种性能的关系 ,以缩短新产品的开发周期。     

辐板式非充气塑料轮胎静负荷工况下的力学性能分析

提出一种聚氨酯辐板与橡胶胎面相复合的辐板式非充气塑料轮胎,并利用有限元软件ABAQUS在静负荷工况下对相同规格的辐板式塑料轮胎和子午线橡胶轮胎的接地性能和力学性能进行分析和对比。结果表明,相比子午线橡胶轮胎,辐板式塑料轮胎接地印痕形状更合理,沿胎面横向的接地压力分布更均匀,减轻了易发生磨损胎肩的负担;另外,辐板式塑料轮胎径向刚度明显较高,并且在接地区域内的弯曲变形的支撑板起到了缓冲和承载的作用,说明辐板式塑料轮胎具有优越的承载性能和良好的舒适性能。     

胎面基部胶厚度对轮胎性能的影响

通过控制胎面挤出过程,调整基部胶厚度占胎面总厚度的比例(以下简称基部胶厚度占比,分别取20%,35%和50%),研究胎面基部胶厚度占比对轮胎性能的影响。结果表明,适当增大基部胶厚度占比可以提高轮胎的耐久性能,减小轮胎过坎冲击力,提高乘坐舒适性,增大侧向力,提高操纵性能,增大纵向力和接地面积,提高抓着性能和制动性能,并且降低滚动阻力系数,提高燃油经济性。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.