排序方式: 共有44条查询结果,搜索用时 15 毫秒
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以湘黔铁路资水大桥为研究对象,就冲刷对铁路重力式实体桥墩稳定性的影响进行研究。采用弹性半空间地基模型分析基底冲刷淘空面积对桥墩稳定性的影响,并通过Matlab计算程序给出影响曲线表达式。通过曲线拟合出粒径和局部冲刷深度之间的关系。研究结果表明:基底冲刷淘空面积对桥墩稳定性各检算项目都有明确的影响,其中墩顶弹性水平位移和合力偏心矩较敏感,在基底冲刷淘空面积较小时率先达到最大容许值,此时二者对应的冲刷淘空面积占基底总面积百分比的最小值分别为14.3%和17.8%;当其他因素一定时,河床土粒径对局部冲刷深度有明显的影响,这种影响在粒径小于0.12m的范围内变化时最为强烈。分析结果反映出适当增大桥墩周围河床土粒径可以有效提高其冲刷稳定性。 相似文献
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综合利用二维和三维机械软件进行设计和加工结构复杂零件,可以充分发挥二维软件的便捷和三维软件立体建模、分析等功能.介绍了将Solid Works和Auto CAD综合运用,利用已有机械资料进行设计修改的做法. 相似文献
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风沙环境下混凝土、砂浆和水泥石的固体颗粒冲蚀磨损试验研究 总被引:5,自引:0,他引:5
根据戈壁的风沙流环境特点,采用气流挟沙喷射法,进行混凝土、砂浆和水泥石的冲蚀磨损试验,研究风沙流速度、冲蚀角度、冲蚀时间和沙流量对混凝土、砂浆和水泥石冲蚀磨损的影响.结果表明:混凝土、砂浆和水泥石的冲蚀率与风沙流速度近似呈线性关系,相比于混凝土和水泥石,砂浆的冲蚀率受风沙流速度的影响更大,拟合直线的斜率达2.25;混凝土、砂浆和水泥石的冲蚀率随冲蚀角度的增加而增加,冲蚀角为90°时冲蚀率最高,与脆性材料的冲蚀规律一致,其中砂浆的冲蚀率受冲蚀角度的影响更大;混凝土、砂浆和水泥石进入稳态冲蚀阶段所需的孕育期不同,在同样的试验条件下,混凝土和水泥石约需4 min,砂浆约需5 min;在相同的冲蚀时间内,C30混凝土试样的冲蚀率随沙流量的增大先降低后增大. 相似文献
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针对管件在焊接过程中定位不够精确且制造误差较大的问题,在分析管件特殊性的基础上,采用旋转法对管件焊接空间位置进行了优化.提出了利用顶点对象的实现方案,并基于Solid Edge平台,利用VB语言加以实现.通过初步验证表明,此方法有效可行. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(11):871-885
This article presents a model for solving solid–fluid interactions in vehicles carrying liquids. A tractor–semitrailer model is developed by incorporating suspension systems and tire dynamics. Owing to the solid–fluid interaction, equations of motion for the vehicle system are coupled. To simplify the complicated solution procedure, the coupled equations are solved separately using two different codes. Each code is analyzed separately; but as the parameters of the two codes depend on each other, the codes must be connected at the end of each time step. To determine the dynamic behavior of the system, different braking moments are applied. As the braking moments increase, braking time decreases. However, it turns out that increasing the braking moment to more than a certain level produces no significant results. It is also shown that vehicles carrying fluids need a greater amount of braking moments in comparison to vehicles carrying solids during braking. In addition, as the level of the fluid inside the tanker increases, from one-third to two-third of the tanker’s volume, the sloshing forces applied to the tanker’s walls increase. It was also concluded that the strategy used in this article to solve for the solid–fluid interaction by incorporating vehicle dynamic effects represents an effective method for determining the dynamic behavior of vehicles carrying fluids in other critical maneuvers. 相似文献
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环境保护监理是近年来监理工程师的主要工作之一,文章通过对钦州港大榄坪1#、2#散杂货泊位工程施工中存在的环境问题进行分析,提出了防治环境污染的监理措施和方法。 相似文献