轻型载重子午线轮胎子口裂病象的优化

子口裂病象是载重子午线轮胎的常见病象。以8.25R16轻型载重子午线轮胎为研究对象,通过有限元分析方法对子口性能进行优化。并分析了该规格子口裂病象生产的原因。     

Study of immersed heat exchange surface for high-efficiency heat recovery from wire-rim tires in a fluidized-bed boiler

In an internally circulating fluidized-bed (ICFE) boiler, the fluidized bed is separated by a partition into main combustion and heat recovery chambers. The flows in these chambers are generated by using silica sand as the fluidizing medium. To determine the overall heat transfer coefficient (HTC) of the boiler's panel-type immersed heat transfer tubes, combustion tests were performed with wire-rim tires. The overall (HTC) of a panel tube array was lower than that of a zigzag tube arrangement. In practice, the heat absorbed by the fins makes the coefficients of either type of tube array almost identical. The air flowrate in the circulating bed at the bottom of the heat recovery chamber can be changed to control the overall HTC to a value virtually identical with that of a zigzag tube array. The combustion of wire-rim tires leads to a buildup of wires in the zigzag array, hampering the transfer of heat. Yet, the panel-type array showed no buildup so that it was possible to maintain steady operation with this type of tube arrangement. © 1997 Scripta Technica. Inc. Heat Trans Jpn Res. 25 (2): 120–134, 1996     

闸下应用废旧轮胎消能防冲的三维数学模型建立

水闸冲刷问题是水利工程中普遍存在的问题,诸多研究人员对该问题进行了系统地研究,研究结果显示使用汽车的废旧轮胎对海漫段增大糙率,可以起到减少冲刷的作用。通过对比分析不同的湍流模型、数值计算方法、网格划分尺度、壁面处理方法,最终采用RNG k-ε湍流模型、PISO算法,将整个流场划分为67.27万网格,选择标准壁面函数对流场进行模拟计算。计算结果与模型试验实测结果吻合较好,说明模型能更好地用于加糙后的流场模拟计算。     

内填散体材料废弃轮胎叠合体承载能力研究

为提高废弃轮胎在土木工程上的利用率,提出利用废弃轮胎环箍约束散体材料,形成具有良好 载荷能力的叠合体。通过竖向载荷试验,测得不同因素对叠合体承载能力和变形特点的影响情况。分 析出叠合体的承载力主要与填充材料的性质和轮胎的直径有关,实验表明叠合体的承载力与内摩擦角 或轮胎的直径呈正相关关系,当后者增大时,前者也随之增大;当叠合体内填充不同的材料时,它的横向 变形量沿高度分布情况也不同,即变形特点与填充材料有关;旧轮胎能够提供相当大的环向约束力,给 出了横向约束力和横向位移的计算公式,具有较好的计算精度;该叠合体能够承受很大的上部载荷,其 颗粒材料的抗剪强度和轮胎的环向约束能力被充分发挥。     

轮胎动态试验系统开发初论

初步论述了轮胎动态试验系统的开发意义及其主要功能。在轮胎静特性试验台的基础上开发的轮胎动态试验系统,其主要特点是轮胎的力、力矩、位移、角度、速度、压力等实时独立可控、可测,从而可以测量复杂工况下的轮胎动态特性,包括稳态特性与非稳态特性,低速特性与高速特性。     

Laboratory large-scale pullout investigation of a new reinforcement of composite geosynthetic strip

In this paper, more than 70 large-scale pullout tests were performed to evaluate the performance of an innovative composite geosynthetic strip(CGS) reinforcement in sandy backfill. The CGS reinforcement is composed of a geosynthetic strip(GS) and parts of a scrap truck tire as transverse members. The experimental pullout results for the CGS reinforcement were compared with the suggested theoretical equations and ordinary reinforcements, including the GS, the steel strip(SS), and the steel strip with rib(SSR). The pullout test results show that adding three transverse members to the GS reinforcement(CGS_3) with S/H=6.6(where S and H are the space and height of the transverse members, respectively)increases pullout resistance by more than 120%, 170%, and 50% compared to the GS, the SS, and the SSR,respectively. This result shows that the CGS_3(CGS with three transverse members) reinforcement needs at least 55.5%, 63%, and 33.3% smaller length compared to the GS, the SS, and the SSR, respectively. In general, implementation of mechanically stabilized earth wall(MSEW) with the proposed strip may help geotechnical engineers prevent costly designs and solve the problem of MSEW implementation in cases where there are limitations of space.     

Use of waste tire steel beads in Portland cement concrete

Large quantities of waste tires are generated every year. The proper disposal of the tires creates an increasing problem that needs to be addressed. Many researchers have investigated the use of recycled tire products in several traditional Civil Engineering materials. The use of crumb rubber and tire chips in Portland cement concrete has been the subject of many research projects over the last years. This study is focusing on the use of steel beads, a by-product of the tire recycling process, in concrete mixtures. Different concrete specimens were fabricated and tested in uniaxial compression and splitting tension. The main variable in the mixtures was the volumetric percentage of the steel beads. The experimental results indicate that although the compressive strength is reduced when steel beads are used, the toughness of the material greatly increases. Moreover, the workability of the mixtures fabricated was not significantly affected.     

基于CMI的废旧轮胎回收系统多周期LRIP

为提高废旧轮胎回收的效率和效益,针对废旧轮胎规范化回收系统优化问题,建立了一种基于回收商管理库存方式的多周期定位-路径-库存问题优化模型,并据此进行回收中心开设地点选择、收集车辆路径安排以及回收点与回收中心的两级库存控制的联合优化决策。设计了一种两阶段启发式算法:阶段1采用先定位-分配,后安排车辆路径和库存的方法,基于系统总成本最小求得初始解;阶段2采用改进启发式搜索方法搜寻更优解。示例分析结果表明了该模型和算法的有效性,并证明了回收商管理库存方式可以显著提高废旧轮胎回收系统的运营绩效。     

某6×4自卸车前轮啃胎问题分析与整改

轮胎是车辆行驶的重要部件,但轮胎的非正常磨损——啃胎,给用户带来较大损失,特别是近期市场上反馈部分某6×4自卸车前轮啃胎严重的问题.对此,通过市场调研,对可能引起啃胎的前桥、轮胎、车架等方面进行了分析.由于是部分车辆存在啃胎现象,排除了整车设计参数的不匹配问题,主要是因为在生产制造环节,因前桥、车架、轮胎等主要部件没有调整到设计要求标准.根据分析,在生产制造过程中制定了一系列的整改控制方案.主要是在前桥装配时确保前桥参数符合设计标准并记录;前轮配重百分百检测,车架生产严格控制对角线和平行度;确保部件及装配质量得到有效管控,整车装配完成后进行四轮定位检测,保证车辆前轮前束等参数调整到设计要求范围才能出厂.     

全钢斜帘子午线轮胎与全钢斜帘活面子午线工程轮胎制造技术

在考虑降低生产装备制造成本,提高自动化程度和轮胎制造精度的同时,改变研发途径,从轮胎设计作为改变轮胎制造工艺起点之一,以保证胎侧强度,降低钢丝帘线用量为前提,达到轮胎进一步轻量化、扁平化为主线,研发具有自主知识产权的新型全钢斜帘子午线轮胎和全钢斜帘活面子午线工程轮胎和成型硫化工艺和装备。