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141.
预应力混凝土T梁裂缝产生的机理分析与控制 总被引:1,自引:0,他引:1
预应力混凝土T梁在我国高速公路桥梁中使用广泛,T梁结构出现裂缝将影响整体梁桥的使用功能。结合两个典型的工程实例,分析了T梁在预制过程中和在运营过程中发生裂缝的原因和控制措施。 相似文献
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We formulate a game-theoretic model of a concession agreement between a government and a private party, a concessionaire, who has to engage a set of service providers as part of the operating responsibilities. We use the model to examine the importance of a government's tax policy to induce private investments in transportation infrastructure. Our analysis brings to fore insights that are useful in the design of partnership agreements, such as the importance of early and binding government commitments to ensure stable partnerships, and thus, successful projects. Our analysis shows that these strong commitments are even more critical in situations where the success of the partnership requires participation of additional, self-interested parties, such as specialized service providers. Finally, we consider variations of the model where government preferences are explicitly captured, and where the returns from the fixed cost portion of the concessionaire's investment are exempt from taxes. We show that both variations can lead to outcomes where the concessionaire's tax burden is shifted to the service providers. This flexibility can be critical in the design of partnership agreements for (high-risk or highly specialized transportation) projects where additional incentives may be needed to induce private party participation. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(11):841-854
Independently rotating wheels in railway vehicles could represent an alternative to standard technology as a solution to dynamic problems such as hunting instability or steering forces in curves. Among the proposed design solutions, the train with independently rotating wheels and with the most practical applications is that developed by Talgo. The Talgo technology is based on the use of a passive steering technique of the wheelset through a mechanism. The absence of automatic control systems means that a careful selection of the mechanical parameters of the vehicle is required to improve its dynamic characteristics. Aspects such as dynamic stability or the effect of vibration on passenger comfort could be analysed by extracting the modal properties of the train from mathematical models. In this article, a methodology for determining the low-frequency modal properties of articulated trains equipped with independently rotating wheels and passive steering system (Talgo-type) is proposed. The singularity of this application based on the use of non-conventional wheelsets necessarily involves the development of a specific methodology. 相似文献
147.
独立悬架汽车转向系统刚度测量 总被引:6,自引:0,他引:6
汽车转向系统刚度是影响汽车操纵稳定性的重要因素之一,本文介绍了一种实用的测量独立悬架汽车转向系统刚度的试验方法,分析了汽车转向系统的受力状况,推导了转向系统中各环节刚度的计算公式,对一辆实车进行的试验测量得到了可靠的数据结果,对进一步探讨转向系统刚度对汽车操纵稳定性的影响具有重要的意义。 相似文献
148.
汽车转向系减振器原理及其阻尼特性的试验分析 总被引:3,自引:2,他引:3
介绍了汽车转向系减振器的原理及其发展概况,提出了应用高频电液伺振器进行转向系减振器阻尼特性测试的试验技术及数据处理分析方法,并给出了一种轿转转向系减振器阻尼特性的试验分析结果,建立了其非线性阻尼参数模型。 相似文献
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前置组合式转向梯形机构的运动模型及优化设计 总被引:4,自引:0,他引:4
前置组合转向梯形机构具有布置灵活,传动可靠等优点,但机构复杂,设计困难,本文从分析运动入手,建立了优化数学模型及算法,开发了优化设计软件系统,并给出了设计分析实例。 相似文献
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