聚脂纤维沥青混合料路用性能研究分析

纤维沥青混合料在高速公路建设中得到了广泛的应用。文章通过对比分析有纤维沥青混合料和无纤维沥青混合料的力学特性、水稳定性、高温稳定性、低温抗裂性能及疲劳性能,全面评价了纤维沥青混合料的优良路用性能,并简单分析了纤维改善沥青混合料路用性能的作用机理,最后从技术经济的角度,定性分析了采用聚脂纤维沥青混凝土作为高速公路沥青路面上面层的经济效益。研究表明,添加聚酯纤维后的沥青混合料具有优良的路用性能。     

车用减振器的外特性建模与仿真

针对某轿车的弹性阀片和弹簧结合型减振器的结构形式，建立了减振器复原行程开阀前、开阀后及压缩行程的阻尼力力学模型，推导出了减振器阻尼力的计算公式，并通过计算机仿真得出该轿车减振器的模拟工作特性。计算机仿真和生产实践证明，所建立的数学模型是正确的，计算方法也符合实际要求。     

中小城市公交场站用地指标研究

国内目前针对中小城市公交场站的研究不足,中小城市场站建设缺乏科学指导,场站用地难以得到保障.结合中小城市公交发展特点及场站模式,通过科学的分析计算,确定场站停车坪、建筑用地、场前区及绿化用地规模,探讨与之相符的中小城市公交场站用地指标,对于中小城市场站规划建设具有一定的现实意义.     

Real-time queue length estimation for congested signalized intersections

How to estimate queue length in real-time at signalized intersection is a long-standing problem. The problem gets even more difficult when signal links are congested. The traditional input–output approach for queue length estimation can only handle queues that are shorter than the distance between vehicle detector and intersection stop line, because cumulative vehicle count for arrival traffic is not available once the detector is occupied by the queue. In this paper, instead of counting arrival traffic flow in the current signal cycle, we solve the problem of measuring intersection queue length by exploiting the queue discharge process in the immediate past cycle. Using high-resolution “event-based” traffic signal data, and applying Lighthill–Whitham–Richards (LWR) shockwave theory, we are able to identify traffic state changes that distinguish queue discharge flow from upstream arrival traffic. Therefore, our approach can estimate time-dependent queue length even when the signal links are congested with long queues. Variations of the queue length estimation model are also presented when “event-based” data is not available. Our models are evaluated by comparing the estimated maximum queue length with the ground truth data observed from the field. Evaluation results demonstrate that the proposed models can estimate long queues with satisfactory accuracy. Limitations of the proposed model are also discussed in the paper.     

信息分发模型研究

针对大量研究工作主要关注信息分发本身的设计和实现而对信息分发模型研究较少的问题,提出一种通用的信息分发描述模型,描述战场环境下的复杂信息分发模式,为信息分发系统的设计和研制提供指导和帮助.结合提出的描述模型,给出四种信息分发模式,供研究人员参考.     

"神州号"双层动车组A4修的技术改造

针对神州号内燃动车组近7年运营中暴露出来的故障和设计缺陷进行系统分析,并结合在专业工厂进行A4级修理(厂修)具备改造条件的前提,通过设计、测绘、样品试制、试验等手段,对车组进行了系列加装改造,以此消除了原型设计制造缺陷,延长和提高部分配件的使用寿命,恢复了其基本性能,保证了动车组安全、舒适、高效运营的需求.     

聚酯玻纤布在桥面防水粘结层中的应用

通常,公路桥梁桥面铺装防水粘结层选用的卷材或涂膜类材料效果均不佳,为了提高桥面与沥青铺装层之间的粘结性能,选用SBS改性沥青+聚酯玻纤布的形式作为防水粘结材料,通过剪切试验确定粘层油用量,铺筑试验路,并进行拉拔试验,结果表明,聚酯玻纤布的层间粘结性能良好。     

北极航线探讨

随着全球气温的不断升高,人类将关注的目光集中到北极。结合大量资料对北极航线的范围、主要探险史、航道现状等方面作出初步分析,探讨东北航道与北方海航道的区别,预测北极航线的发展前景。     

Finite element simplified fatigue analysis method for a non-tubular joint of an offshore jacket platform

This paper proposes the finite element simplified fatigue analysis method for fatigue evaluation of the composite non-tubular joint structure of an offshore jacket subjected to wave loads. The skirt pile sleeve of the offshore jacket, which had been in service, was taken as an example of the non-tubular joint structure. SACS software was used for global analysis of multi-directional wave loads for the jacket platform, and ALGOR software was used to build a finite element model, perform finite element analysis, post-process stress results for acquiring the stress range, and perform fatigue evaluation. The analysis results indicate that the extreme stress range is within the allowable stress range and meets the requirements of DNV code. That means the simplified fatigue analysis method is effective and can be used in fatigue design for the non-tubular joint structure of an offshore jacket.