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11.
东营黄河大桥主桥上部结构(116 200 220 200 116)m预应力混凝土刚构连续结合梁的箱梁采用菱形挂篮悬臂施工法。介绍了主墩和次主墩0号块施工分别选取的支架方案,以及现浇直线段的支架方案。阐述了挂篮的试压方法,并对其试压结果进行了分析。 相似文献
12.
Shogo Nakasumi Katsuyuki Suzuki Daiji Fujii Hideomi Ohtsubo 《Journal of Marine Science and Technology》2003,7(4):180-188
This article presents a mixed method of analyzing shell elements and solid elements using the overlaying mesh method. In
the structural design of a ship's hull, the shell elements are used for the global model. However, the solid elements are
necessary to analyze the stress concentration zones or the vicinity of a crack. In such cases, the models are analyzed using
zooming analysis, in which the results of a global model analysis are transferred to a local model analysis by imposing boundary
conditions. This method is more advantageous than zooming analysis in terms of the accuracy of the solution and the modeling
flexibility. Some examples of a plate model with a cracked surface or with a projection are shown in order to demonstrate
the effectiveness of the method.
Received: August 6, 2002 / Accepted: November 25, 2002
Address correspondence to: S. Nakasumi (sumi@nasl.t.u-tokyo.ac.jp)
Updated from the Japanese original, which won the 2002 SNAJ prize (J Soc Nav Archit Jpn 2001;189:219–224; and 190:655–662) 相似文献
13.
Takafumi Kawamura Hideaki Miyata Kohji Mashimo 《Journal of Marine Science and Technology》1997,2(4):245-256
A time-marching CFD simulation is performed for self-propelling ships. The flow about the hull is simulated by the finite-volume
method, and the propeller action is approximated as a propeller disk for which the solution is given by a simplified propeller
model. The interaction of two flow models is treated in a time-marching procedure converging towards the steady self-propelling
condition. This method is applied to five tanker models, and detailed comparisons are made between the simulated results and
corresponding experimental results. It is shown that the flow field in the self-propelling condition is qualitatively well
reproduced in the simulation, and the estimated thrust deduction factors for the five hull forms agree well with measured
ones. However, the effective wake factors are underestimated, since the Reynolds number in the simulations differs from that
in the experiment. 相似文献
14.
15.
陆宏轮 《西南交通大学学报》1994,29(5):541-548
本文应用集合概念,对组合结构作了形式化描述。通过矩阵分析,导出了力法方程的统一列式。给出了算法实施的流程框图和具体算例。 相似文献
16.
17.
本文根据轮/轨蠕滑理论提供了计算和分析B_0—B_0机车转向架直线运行横向轮/轨力的方法,并以SS4型电力机车作为验证实例,理论计算和实际测试的结果相接近。作者采用这种方法对轮/轨力进行可靠的分析,旨在论证我国现有电力机车转向架蛇行稳定性所要求的最佳轮对定位刚度。本文论证结果符合于作者在文献[1]中提出的轮对定位新方案,它可适用于最大运行速度为100km/h的现有SS型电力机车。 相似文献
18.
空间复合材料加筋板流固耦合振动分析 总被引:6,自引:0,他引:6
本文用结构有限元与流体边界元方法研究了空间复合材料加筋板结构的流固耦合自由振动,推导了用于结构分析的分项插值型复合材料八节点板单元和三节点梁单元,以及用于流场分析的线性边界单元。用修正的RIRZ向量法与波前法相结合的方法求解特征值问题,避免了因附连水质量引起的结构质量矩阵为满阵的内存困难和非对称矩阵方程约化困难。算例表明,附连水质量对复合材料结构的动力特性影响要比各向同性材料严重得多。 相似文献
19.
采用空间向量原理,从空间电荷向量端点轨迹逼近于国出发,推导出PWM脉冲模式的算法,同时采用8097微处理器实现这种脉冲模式和对逆变器进行控制。由实验波形看出,在较低频时逆变器的输出电流为三相对称的近似的正弦波电流,消除了低频时有害的寄生脉动转矩。 相似文献
20.
A numerical method was developed to predict the water impact pressure caused by green water phenomena. The density function method was employed in the framework of a locally refined overlapping grid system. The simple problem of a rectangular body placed in regular waves was considered and the simulation results were compared with tank experiments. Good agreement with experiment was shown for wave–body interactions and for the pressure values at three different positions on the body. The case of a rectangular body with a vertical wall on the deck was also considered and the comparison showed satisfactory agreement. It was demonstrated that this method could be extended to a moving body problem, in which the body was free to undergo heave, pitch, and surge motions. 相似文献