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11.
一种确定高圆簧横向刚度的有效方法 总被引:16,自引:1,他引:16
米彩盈 《西南交通大学学报》1998,33(3):294-298
文中将高圆簧简化为等截面弹性直杆,导出高圆簧横向刚度计算式,并用试验结果进行修正,提出高圆横向刚度分析方法。理论分析和试验结果表明:高圆簧横向刚度的大小取愉于高圆簧的自由高度和工作高度,即由其结构几何参数和工作载荷决定。按文中方法确定的高圆簧横向刚度理论值与试验结果间的最大误差不超过10%,满足工程理论分析要求。 相似文献
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Environmental contours are often applied in probabilistic structural reliability analysis to identify extreme environmental conditions that may give rise to extreme loads and responses. They facilitate approximate long term analysis of critical structural responses in situations where computationally heavy and time-consuming response calculations makes full long-term analysis infeasible. The environmental contour method identifies extreme environmental conditions that are expected to give rise to extreme structural response of marine structures. The extreme responses can then be estimated by performing response calculations for environmental conditions along the contours.Response-based analysis is an alternative, where extreme value analysis is performed on the actual response rather than on the environmental conditions. For complex structures, this is often not practical due to computationally heavy response calculations. However, by establishing statistical emulators of the response, using machine learning techniques, one may obtain long time-series of the structural response and use this to estimate extreme responses.In this paper, various contour methods will be compared to response-based estimation of extreme vertical bending moment for a tanker. A response emulator based on Gaussian processes regression with adaptive sampling has been established based on response calculations from a hydrodynamic model. Long time-series of sea-state parameters such as significant wave height and wave period are used to construct N-year environmental contours and the extreme N-year response is estimated from numerical calculations for identified sea states. At the same time, the response emulator is applied on the time series to provide long time-series of structural response, in this case vertical bending moment of a tanker. Extreme value analysis is then performed directly on the responses to estimate the N-year extreme response. The results from either method will then be compared, and it is possible to evaluate the accuracy of the environmental contour method in estimating the response. Moreover, different contour methods will be compared. 相似文献
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Rapid motor vehicle crash detection and characterization is possible through the use of Intelligent Transportation Systems (ITS) and sensors are an integral part of any ITS system. The major focus of this paper is on developing optimal placement of accident detecting omnidirectional sensors to maximize incident detection capabilities and provide ample opportunities for data fusion and crash characterization. Both omnidirectional sensors (placed in suitable infrastructure locations) and mobile sensors are part of our analysis. The surrogates used are acoustic sensors (omnidirectional) and Advanced Automated Crash Notification (AACN) sensors (mobile). This data fusion rich placement is achieved through a hybrid optimization model comprising of an explicit–implicit coverage model followed by an evaluation and local search optimization using simulation. The compound explicit–implicit model delivers good initial solutions and improves the detection and data fusion capabilities compared to the explicit model alone. The results of the studies conducted quantify the use of a data fusion capable environment in crash detection scenarios, and the simulation tool developed helps a decision maker evaluate sensor placement strategy. 相似文献
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通过室内试验对水泥稳定冷再生混合料的无侧限抗压强度、抗压回弹模量、劈裂强度、抗冲刷性能进行了系统的研究.试验结果表明,水泥剂量为5%时,冷再生材料的强度和其它路用性能指标均满足规范的要求. 相似文献
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交通拥挤收费不仅能缓解交通拥挤,还能通过收费使交通基础设施获得建设维护的部分资金,其合理性和必要性已经得到充分的论证,然而对于实施的一些基本问题,认识的还很不充分,也就对拥挤收费的实施造成了一些基本障碍。从交通拥挤收费实施的基本原则出发,对收费的基本方式、收费实施的影响因素和实施的策略等方面进行了研究,认识到交通拥挤收费不仅仅是一个技术性的问题,更是一个牵涉到政治、经济、文化和民众心理的问题,因此在实施的过程中必须考虑到收费的公平性、效益性和可持续性。在此基础上,对于目前我国一些城市实施交通拥挤收费的措施提出了一些中肯建议。 相似文献
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纪蓉琴 《华东交通大学学报》2006,23(6):134-137
探讨了中英语篇思维模式差异对英汉学术论文写作中论证方法的影响问题.文章通过分析指出,中英思维模式存在着直觉与抽象、本体与客体和螺旋与直线型差异,并因此导致英汉学术论文中论证方法在修辞手段、引经据典、引用权威等方面的使用差异.文章最后指出,只有了解英汉思维模式的差异,分析其文化成因,才能真正实现跨文化写作的成功. 相似文献