基于理论法的同步碎石封层设计

封层施工中,沥青粘结料与碎石的撒布量是关键。如果石料的覆盖率过低,会引起路面损坏;如果石料的覆盖率过高,会致使一些已经粘到沥青层的石料脱落,被车轮带起打碎汽车挡风玻璃,以理论法为基础,进行橡胶沥青同步碎石封层的设计,可以更精确地确定沥青与碎石的撒布量。     

基于参数更新的体外索张力识别方法

以有限元分析模型参数更新理论为基础,提出了一种通过测试自振频率得到体外索张力的新方法,其参数更新的目标是使试验实测体外预应力体系的频率与有限元模型计算所得频率最为接近,进而识别出体外索张力大小,经实例验证,用所提出的方法来识别体外索的张力具有很高的精度．     

考虑几何非线性效应的桩柱式高墩分析

该文首先简述了几何非线性分析的理论,并列举了几何非线性目前求解的主要的方法,最后用牛顿-拉普森法对算例进行求解。计算结果表明,高墩的设计计算,几何非线性的影响不可忽视。     

NUMERICAL SIMULATION AND EXPERIMENTS FOR PANEL FORMING BASED ON CAD/CAE SYSTEM

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The IMMa optimisation algorithm without control input parameters

The IMMa optimisation algorithm (IOA) consists of a heuristic method based on a differential evolution algorithm for choosing the Magic Formula (MF) tyre model parameters. In a previous paper, we demonstrated that the IOA improved the searching procedure of optimum MF parameters with respect to the starting value optimisation (SVO) methods. But we had to introduce some control input parameters that were fixed during the running process. Now, the new version does not require control input variables to be chosen by the user. That is, we use an algorithm with self-adapting control parameters and it continues being easy to use, robust and fast. Hence, users do not need any kind of knowledge to use the IOA.     

Prioritizing bicycle paths in Belo Horizonte City,Brazil: Analysis based on user preferences and willingness considering individual heterogeneity

Using bicycles as a commuting mode has proven to be beneficial to both urban traffic conditions and travelers’ health. In order to efficiently design facilities and policies that will stimulate bicycle use, it is necessary to first understand people’s attitudes towards bicycle use, and the factors that may influence their preferences. Such an understanding will enable reliable predictions of bicycle use willingness level, based on which cycling facility construction can be reasonably prioritized.As people often have different perceptions on exercising, green transportation, and traffic conditions, effects of potentially influencing factors on people’s willingness of using bicycles tend to be highly heterogeneous. This paper uses a random parameter ordered probit model to analyze how travelers’ willingness of using bicycles is influenced by various socio-economic factors in Belo Horizonte City, Brazil, with the consideration of individual heterogeneity. The data was collected through the 2010 bicycle use survey in Belo Horizonte City. Results show that, first, the willingness of using bicycle is favored by middle income class household, and negatively related with commuting time. Second, people who rent apartments tend to be more willing to use bicycles. Third, if a person is currently walking a long time to work, he/she would be most willing to commute with a bicycle in the future. Those currently commuting a relatively short distance by motorcycle and bus follow this group in terms of willingness to commute by bicycle in the future. Car users seem to be difficult to convert to bicycle users. Moreover, the estimation shows clear evidence that significant individual heterogeneity indeed exists, especially for education level, necessitating the consideration of such an effect. With the calibrated model, residents’ willingness of using bicycle commuting is then estimated for the entire Belo Horizonte City using the 2010 Census and the 2012 O/D survey data. The results are cross validated using the bicycle path preference information, also obtained from the 2010 bicycle use survey.     

机器人用高精度RV减速机几何回差分析

分析并建立了机器人用高精度ＲＶ减速机几何回差计算的数学模型。并通过计算机模拟与生产实践予以验证。     

动力分散型城郊快速电动车组转向架方案设计

介绍一种动力分散型城郊快速电动车组转向架的主要技术参数和基本结构方案。     

重塑非饱和粘性土的抗剪强度参数与物理状态变量的关系研究

采用分层击实的方法重塑制备三轴试验土样。按5级围压(100kPa,200kPa,300kPa,450kPa,600kPa)完成了土样的三轴压缩UU试验。试验结果表明:在水分状态和密度状态空间,该重塑非饱和粘性土抗剪强度参数的分布具有明显的规律性,但这种规律性不易用简单函数表达。粘聚力的分布呈倾伏的不规则背斜面,内摩擦角的分布呈变形的W型折曲面。粘聚力和内摩擦角与含水量的关系是强非线性的,与干密度的关系总体上是弱非线性的。存在两个特征含水量18 16和16 34,不同密度状态的土样在特征含水量18 16处粘聚力和内摩擦角均取极大值,在特征含水量16 34处内摩擦角均取极小值。