排序方式: 共有65条查询结果,搜索用时 140 毫秒
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山东省南四湖地区蕴藏大量的煤炭资源,潜在货运量充足。区域内多条支流汇入南四湖,结合已建有的航道,水运资源开发潜力巨大。依据重要支流的自然条件、水利设施和跨河建筑物等,分析航道开发中可能遇见的问题,并提出初步的解决方法。 相似文献
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王永文 《国防交通工程与技术》2013,(2):54-56
高速铁路桥梁建设发展迅速,随之而产生的桥梁支座更换工作也越来越多。桥梁支座更换最常用的方法是梁体顶升法,施工时必须对梁体结构的变形及应力状态进行控制。主要阐述了桥梁支座更换方案及梁体顶升过程的模拟分析,给出了三跨连续梁不同墩顶竖向位移对梁体线形及内力的影响,从而根据规范要求,确定顶升的位移控制限值及对应梁体混凝土应力限值,并作为施工的依据,施工监测数据与结构分析数据取得一致,保证了支座更换的顺利完成。 相似文献
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主要研究探讨了提高随动系统限速制动可靠性的方法,简要分析了随动系统制动过程的工作原理和一般常用的制动方法,探讨了限速制动的工作过程和制动规律,分析了限速制动冗余设计的必要性。通过推导和工程简化,得到了相应公式和关系曲线,借鉴某型舰炮的硬件设计思路,提出了一种硬件电路实现限速制动冗余设计的方案,同时以某型发射架为例,计算了电路的参数。分析研究表明,硬件冗余设计原理简单可行,最后对设计方案的改进做了说明。 相似文献
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Wei Liu Fengchun Sun Jiangyi Lv 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2017,55(5):601-625
This paper describes an integrated chassis control framework for a novel three-axle electric bus with active rear steering (ARS) axle and four motors at the middle and rear wheels. The proposed integrated framework consists of four parts: (1) an active speed limiting controller is designed for anti-body slip control and rollover prevention; (2) an ARS controller is designed for coordinating the tyre wear between the driving wheels; (3) an inter-axle torque distribution controller is designed for optimal torque distribution between the axles, considering anti-wheel slip and battery power limitations and (4) a data acquisition and estimation module for collecting the measured and estimated vehicle states. To verify the performances, a simulation platform is established in Trucksim software combined with Simulink. Three test cases are particularly designed to show the performances. The proposed algorithm is compared with a simple even control algorithm. The test results show satisfactory lateral stability and rollover prevention performances under severe steering conditions. The desired tyre wear coordinating performance is also realised, and the wheel slip ratios are restricted within stable region during intensive driving and emergency braking with complicated road conditions. 相似文献
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通过分析塌陷体(土层)与周围未塌陷地基的相互作用,当采用梁、板跨越法处理时结合极限平衡理论对岩溶地段塌陷地基极限承载力的计算公式进行推导.对比得出:在采用跨越处理(梁或板)措施时,塌陷体的地基极限承载力、抗剪强度等是影响周围未塌陷地基土的极限承载力的重要因素.由于梁或板跨越处理时其地基的极限承载力不同,采取夯实(挤密)... 相似文献
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与已有文献中采用的广义位移不同,选取剪力滞引起的附加挠度作为广义位移,在构造广义翘曲位移函数的基础上,提出了一种分析箱梁剪力滞的解析法.基于能量变分法建立控制微分方程,并导出了简支箱梁的附加挠度和广义力矩计算公式.通过对一个混凝土简支箱梁算例的计算表明,按本文方法计算的跨中截面应力与有限元法的结果很接近,从而验证了方法的正确性.研究结果表明,剪力滞引起的混凝土简支箱梁跨中截面的附加挠度很小,工程实践中可以忽略不计,但是,跨中截面的剪力滞翘曲应力达到初等梁应力的11.4%,工程实践中不能忽略. 相似文献
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