骨料生产线司机自助定量装车系统设计

砂石骨料的发运量较大，对发运效率要求较高，本文对比了砂石骨料发运销售“一卡通”和“一码通”软件流程的应用效率以及三种装车发货方式的优劣；介绍了基于“一码通”流程的司机自助定量装车系统的总体架构、工作流程和主要构成；系统通过物流销售系统APP预约下单，“一码通”车辆自助排队调度、汽车衡智能定量称重装车、门禁系统控制车辆进出等，实现了砂石骨料装车预约、排队、上磅、下料、结算、出厂等各工作流程的自动化、智能化控制，提高了砂石骨料的装车发运工作效率。     

基于卷积神经网络的砂石骨料分类模型

混凝土是经济社会建设发展的重大基础材料,而砂石骨料是混凝土主体,砂石骨料质量与混凝土的性能息息相关。在以往的研究中,由于骨料的海量性、不规则性,导致对砂石骨料质量分类研究较少,尚未提出有效的检测方法。本文通过大量砂石骨料物理属性数据,就砂石骨料品质问题展开了研究,提出了基于卷积神经网络的砂石骨料分类模型。实验结果表明,该模型具有一定的可靠性,可为砂石骨料质量检测提供参考。     

牛背脊人工砂石骨料干法生产系统的设计和运用

简要介绍牛背脊人工砂石骨料干法生产系统规模和工艺流程的确定、主要生产设备的配置、砂石骨料生产质量的控制方法以及运行情况,为大中型人工砂石骨料干法生产系统的设计和运行提供参考.     

矿山废石制备砂石骨料的现状研究综述

目前,矿山废石大量堆存造成严重的土地资源浪费和环境污染。基础建设造成混凝土用量增长,机制砂石骨料的供应缺口巨大。由于多数矿山废石具有强度高、力学性能稳定的特点,因此可循环利用制成砂石骨料,既可消纳大量废石资源,又可以缓解砂石骨料的短缺。本文介绍了我国矿山废石资源排放现状,总结了在我国机制砂石供应的现状下,部分专家学者与企业对矿山废石制备砂石骨料的积极探索与实践结果。提出了矿山废石制备砂石骨料过程存在的一些问题,为矿山废石制备砂石骨料的资源化利用方式提供参考。     

精品机制砂石骨料生产线的工艺及设备探讨

以某骨料项目为例,阐述某种类型的精品机制砂石骨料生产线的整体解决方案,重点介绍了生产线的工艺流程、设备配置方案、设备的组合方式以及总图布局、电控装备、除尘设施、储运系统等,意在提供一种具备过程控制环节的砂石骨料生产线的总体设计思路,从而有助于高品质的砂石骨料产品的产出比例更加合理。     

基于移动胶带机的定量自动装车系统设计

骨料生产线传统散装机装车系统智能化程度较低,装车过程中存在司机需配合挪车、散装机易卡料溢料、定量装车困难等问题。基于移动胶带机的定量自动装车系统通过缓冲仓补料、称重仓计量控料、双向可逆胶带机下料均匀装车、利用汽车衡精确装载量等,实现了定量装车、自动补料、中控智能化操作的设计目标,减少了操作员人数,降低了劳动强度,降低了经营成本,提高了装车效率。     

砂石骨料生产线设计要点

正随着天然沙石资源的枯竭和各地环保政策的收紧,人工机制砂石逐渐成为资源的主流。为了充分利用矿山资源和增加企业利润,各大水泥企业纷纷建设砂石骨料生产线。根据每个骨料矿山特点而设计出产品质量合格、安全、环保的生产线,设计起着非常关键的作用。砂石骨料生产线主要由破碎系统、筛分系统、制砂系统(不生产砂则没有)、储存及发运系统和除尘系统组成,现就每一个组成系统的主要设计要点进行总结。     

精品砂石系统的生产实践

为解决矿山富余剥离废岩,我公司以优质、精品、绿色、环保为导向,选择塔式骨料制砂一体化系统制备精品砂石。本文介绍了该系统在精品砂石生产中的优势,并针对试生产过程中发现的一些影响产能的问题进行了分析,并采取了一些改进措施,实现了生产线达产达效。     

浅谈精品砂石骨料环保措施

随着工业的发展和国家对环保要求的不断提高,在机制精品砂石骨料的领域中,还存在着诸多问题。例如,在堆料、破碎筛分以及运输过程中,产生的粉尘污染;在破碎过程中的噪音污染以及对精品砂石骨料进行筛洗后的废水处理等。为了实现绿色生产,可持续发展,这些问题都必须得到合理解决。因此,结合机制砂石骨料生产技术的发展,以预防为主、防治结合的治理原则,对此问题进行相关探讨。     

浅谈曲寨水泥有限公司1000t/h砂石骨料生产线

正近年来,在国家有关部门加大矿山资源开发整治力度、注重环境保护、综合利用矿山资源的方针政策指导下,我国砂石行业加快了发展步伐,加强绿色环保、建设现代化的砂石骨料生产线成为行业发展的主流。在水泥业务增长放缓、不确定因素加强的情况下,水泥企业开始把触角延伸至下游产业链——砂石骨料行业。冀东、金隅、海螺等大型水泥企业陆续进入砂石行业。本文介绍曲寨水泥有限公司1 000t/h骨料生产线项目,希望对同行有所帮助。     

发烟硫酸汽车装车系统的自动化改造

针对现有发烟硫酸汽车装车系统存在的问题,紫金铜业有限公司采用了基于PLC控制的发烟硫酸自动装车系统,该系统由一体式电磁流量计和带触摸屏的PLC控制箱构成。汽车装车系统自动化改造后装车效率提高,工人劳动强度降低,并且避免了少装、多装现象,现场安全性大幅度提高。提出了进一步完善发烟硫酸自动装车系统的几项措施。     

汽车发动机道路行驶工况模拟试验台加载控制系统设计

汽车发动机道路行驶工况模拟试验台利用电涡流机对汽车发动机加载以实现道路行驶工况模拟。在各种道路行驶工况下,测功系统可测量发动机底盘输出功率。介绍了该试验台测功系统工作原理及控制系统组成,详细分析了加载控制电路设计。     

Micromechanics of ITZ‐Aggregate Interaction in Concrete Part II: Strength Upscaling

Cracking in concrete typically starts in the immediate vicinity around the aggregates, i.e., in the region of the so‐called interfacial transition zones (ITZs), but the process is still not fully understood. Notably, crushing of concrete in compression results in fragments with interesting aggregate surface textures. Part of the aggregate surfaces is cleanly separated from the ITZ, while another part of the aggregate surfaces remains covered with a thin layer of cement paste. This suggests two different types of failure: ITZ‐aggregate separation and ITZ failure; which we here study based on the continuum micromechanics approach of the companion paper (part I). It provides access to both traction vectors acting on aggregate surfaces and three‐dimensional stress states within representative ITZ volumes for loading states below the elastic limit of concrete. When inserting these microtractions and microstresses into Rankine‐type strength criteria for the aggregate‐ITZ interface and for the ITZ, respectively, the micromechanics model allows for upscaling this microscopic failure behavior to concrete‐level criteria for crack onset. Comparing the latter to corresponding experimental results, reveals that under tension‐dominated loading both ITZ failure and ITZ‐aggregate separation appear to be realistic, while under compression‐dominated loading ITZ failure appears as the more likely mechanism. Also, comparing model and experiments shows that the ITZ‐aggregate separation strength amounts to at least half of the internal ITZ cohesion strength, but may be much larger than the latter.     

循环荷载下再生混凝土疲劳试验*

为了研究再生混凝土循环荷载下的疲劳寿命,采用实验室废弃[C30]混凝土试块,加工处理制成连续粒径级配的再生骨料（5～31.5 mm）,用这种再生骨料部分取代天然骨料配制的混凝土试样（100 mm×100 mm×300 mm）进行循环荷载试验。结果表明：随着荷载上限幅值的增大,再生混凝土疲劳寿命逐渐减小。并对再生混凝土疲劳寿命随荷载上限幅值进行线性拟合,且相关系数R的绝对值均大于0.9,表明疲劳寿命与荷载上限线性相关。另外,通过对再生粗骨料取代率与疲劳寿命之间的变化关系研究,得到了当再生粗骨料取代率小于等于50%时,疲劳寿命减小趋势不明显;当再生粗骨料取代率大于50%时,疲劳寿命曲线斜率明显增大,表明疲劳寿命减小趋势迅猛。因此,当采用再生粗骨料进行路基路面施工时,建议再生粗骨料取代率小于等于50%。     

浅谈汽车低温漆修补

介绍了整车涂层系统的组成、常见涂层缺陷以及修补材料及工具,着重介绍了整车低温漆修补步骤及漆膜性能评价。     

基于LabVIEW的车用橡胶件动刚度测试系统

根据车用橡胶件动态特性的测试要求,设计了一种新偏心轮式机械激励和砝码加载方式的车用橡胶件动刚度测试系统。该系统采用PCI-6220数据采集卡对动态试验信号进行采集,并运用LabVIEW软件对采集的数据进行分析处理,得到橡胶件的动刚度和阻尼系数等参数。试验证明,该系统测试结果准确可靠,且成本低,使用方便。     

Mesoscopic modeling and simulation of the dynamic tensile behavior of concrete

We present a two-dimensional mesoscopic finite element model for simulating the rate- and moisture-dependent material behavior of concrete. The idealized mesostructure consists of aggregate grains surrounded by an interfacial transition zone embedded in the bulk material. We examine the influence of the most significant constitutive model parameters on global and local response. Different distributions and shapes of the aggregate grains are tested. Three model parameter sets, corresponding to different moisture conditions, are employed in the analysis of two specimens in which the applied loading rate is significantly different. The results indicate that the loading rate has a stronger influence than the saturation level on fracture processes and global strength.     

Aggregate rebound effect on elastic and creep recovery of lightweight concrete

The results of this research indicate that the instantaneous elastic recovery of concrete after unloading is at any time greater than the value calculated using the value of modulus of elasticity for virgin loading at the same age. The differences are caused by the time-dependent stress redistribution in composite material. The elastic rebound of the lightweight aggregate after a long time period under sustained load is much larger than that for normal aggregate. This produces microcracking in the mortar and loss of its resistance to the elastic rebound of aggregate, causing a great increase of instantaneous as well as delayed recovery of compressive strain.     

Influence of the roughness of aggregate surface on the interface bond strength

An experimental investigation on the bond strength of the interface between mortar and aggregate is reported. Composite compact specimens were used for applying Mode I and Mode II loading effects. The influence of the type of mortar and type of aggregate and its roughness on the bond strength of the interface has been studied. It has been observed that the bond strength of the interface in tension is significantly low, though the mortars exhibited higher strength. The highest tensile bond strength values have been observed with rough concrete surface with M-13 mortar. The bond strength of the interface in Mode I load depends on the type of aggregate surface and its roughness, and the type of mortar. The bond strength of the interface between mortar M-13 cast against rough concrete in direct tension seems to be about one third of the strength of the mortar. However, it is about 1/20th to 1/10th with the mortar M-12 in sandwiched composite specimens. The bond strength of the interface in shear (Mode II) significantly increases as the roughness and the phase angle of the aggregate surface increase. The strength of mortar on the interface bond strength has been very significant. The sandwiched composite specimens show relatively low bond strength in Mode I loading. The behavior of the interface in both Mode I and Mode II loading effects has been brittle, indicating catastrophic failure.     

Particle aggregation and capture by walls in a particulate aerosol channel flow

A soft-sphere discrete-element method is used to examine particle aggregate formation and particle capture by walls in a laminar channel flow. Adhesive particulates have been identified as a leading cause of failure in many different microfluidic devices, including those currently being developed by different research groups for rapid biological and chemical contaminant sensing, fluid drag reduction, etc. As these microfluidic devices enter into the marketplace and become more extensively used in field conditions, the importance of particle adhesion and clogging will increasingly limit the reliability of such systems. At a larger scale, clogging of vehicle radiators by small adhesive particles is currently a major problem for construction vehicles operating in various environmental conditions and soil types. Cooling system fouling leads to the need for frequent maintenance and machine down time. Dust fouling of equipment is also of concern for potential human occupation on dusty planets, such as Mars. The paper provides a detailed investigation of the fundamental mechanics leading to adhesion of particle aggregates to channel walls, which involves a combination of aggregate capture, aggregate deformation by particle rolling, and shearing of aggregates from the wall. Cases with different adhesion potential, particle sizes, and flow Reynolds number are examined, with both single-size particles and a binary particle mixture.