重型汽车制动摩擦片的正交试验与优化设计

为解决树脂基纤维增强汽车制动摩擦片存在的热衰退问题,对其粘结剂进行了改性。通过正交试验,分析了高温下摩擦材料各成分对制动摩擦片热衰退性能的影响,探讨了制动摩擦片的摩擦磨损机理,优化了摩擦材料配方。试验结果表明,采用优化后配方研制的制动摩擦片在高温下具有良好的抗热衰退性能,摩擦因数稳定,磨损率低。     

广西道路客运发展探讨

文章介绍了广西道路客运发展现状,分析了铁路发展对道路客运的影响,探讨了广西道路客运的优劣势和作用定位,并在此基础上提出了发展道路客运的原则、策略与措施。     

喷浆法在加固黄河大坝高填土中的应用

文章结合东营黄河大桥桥头高填土跨越黄河大坝的工程实例,介绍采用喷浆法进行大坝高填土加固的设计方法及施工工艺,并对其加固效果进行了评述。     

复合材料船体纵向极限承载能力分析

该文利用梁柱理论推导出复合材料梁柱的极限承载能力公式,讨论了加筋板的初始几何缺陷,载荷偏心,蒙皮屈曲后的有效蒙皮宽度对复合材料长帽形加筋板的极限承载能力的影响。利用复合材料梁柱理论计算船体甲板或船底板结构视加筋板单元构件的极限承载能力,最后由Smith法来计算复合材料船体的极限承载能力。     

轻质夹芯复合材料结构强度评估方法研究

由于具有高强度、高模量、重量轻、耐腐蚀的优良特点,复合材料在船舶上的应用逐渐成为研究热点.目前可查阅的关于船体复合材料结构强度校核的文献很罕见以及各种规范对船体复合材料结构强度校核尚未给出明确的说明.与各向同性材料的强度评估方法相比,复合材料强度评估有很大的不同.本文基于试验结果,分别采用壳单元、实体-壳单元和实体单元模型对复合材料结构进行数值分析,确定用于轻质夹芯复合材料结构强度评估的合理有限元模型.基于渐进损伤分析理论,采用Tsai-Wu失效准则和突降退化模型,对轻质夹芯复合材料的极限强度进行评估.结果表明:计及结果精确性与计算成本,可用壳单元模型分析复合材料结构的应力-应变分布;渐进损伤分析方法结合材料退化模型不仅有效地对复合材料结构的极限强度进行预测,同时还能判断材料的失效模式.     

Research and Application of Drag Reduction by Grouting the Pipe Jacking in Complex Conditions北大核心CSCD

This paper presents the technology measures, equipment selection and required grout properties and re-lated techniques for the grouting base-station arrangement of the drag reduction system of the Fuchun River pipe jacking project, which is characterized by a combined stratum, a longitudinal curve with a large falling head, a large gradient and high water pressure. Drag reduction by grouting can effectively reduce the friction coefficient in pipe jacking construction, decrease the time and frequency of the relay station, improve construction efficiency, and re-duce the grout loss along the stratum fissure while guaranteeing grouting pressure of the terminal, is favorable for sta-ble annular bentonite grouting between the stratum fissure and the segment. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

Support Form and Construction Sequence for Soft Rock Tunnels with Small Spacing,High Stress and Deformation北大核心CSCD

Increasingly, stations are being extended to tunnels due to the effects of topography on mountain rail-ways and the requirements of the stations. A forked tail tunnel arrangement is the most popular one, but the concomi-tant effect of the following tunnel on the antecedent tunnel during construction of a tunnel with small spacing causes cracking of the primary support and secondary lining as well as heaving of the invert, which continues to trouble en-gineers. Different problems are encountered by different tunnels because of the complexities and variations of geo-logical environments. Using the construction of two single-line sections with small spacing for the Xinchengzi tunnel on the Lanzhou-Chongqing railway as an example, the support form for a soft rock tunnel with small spacing and high geostress and deformation, as well as the invert construction sequence of the left and right lines and secondary lining, are analyzed and discussed. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

基于FSS Code的大型船舶机舱布置优化研究

文章介绍了适用于机舱消防安全的相关法规,详述了船舶常用的固定式灭火系统,给出了机舱固定式灭火系统的配备要求。以某30万吨超大型油船为对象,依照FSS Code等法规计算了泡沫浓缩液储量和应急消防泵的排量,推算了应急发电机的功率,最后根据MSC.1/Circular.1528和UI SC 262 对FSS Code中的机舱最大保护空间的容积的统一解释,和SOLAS对火灾危险物的界定,优化了机舱布置。通过研究得出：机舱设计时,要充分考虑机舱防火、灭火要求,科学规划布置舱室及设备,在准确理解规范规则要求的基础上,合理减少机舱最大保护空间,降低设备成本。     

橡胶沥青在复合式道路改造中的应用

文章基于橡胶沥青的工艺原理,结合G321线大(方)纳(溪)路护国镇至安富桥段路面改造工程实例,介绍了橡胶沥青在复合式"白改黑"道路改造工程中的应用技术,并通过质量检测评述了橡胶沥青的工程实效。     

复合支护模式在深基坑桥梁基础中的应用

文章结合某拱桥止推墩基础施工实例,阐述了采用“排桩＋冠梁＋内撑”复合支护模式的深基坑桥梁基础施工方案,并利用有限元数值模型,计算分析了“排桩＋冠梁＋内撑”复合支护结构的受力状况及基坑稳定性。结果表明,该复合支护模式是有效、可行的。