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81.
RENHui-long ZHANGHai-bin DAIYu-zhi SONGJing-zheng 《船舶与海洋工程学报》2003,2(1):1-10
A three-dimensional method of calculating wave loads of turret moored FPSO (Floating Production Storage and Offloading) tankers is presented. The linearized restoring forces acting on the ship hull by the mooring system are calculated according to the catenary theory, which are expressed as the function of linear stiffness coefficients and the displacements of the upper ends of mooring chains. The hydrodynamic coefficients of the ship are calculated by the three-dimensional potential flow theory of the linear hydrodynamic problem for ships with a low forward speed. The equations of ship motions are established with the effect of the restoring forces from the mooring system included as linear stiffness coefficients. The equations of motions are solved in frequency domain, and the responses of wave-induced motions and loads on the ship can be obtained. A computer program based on this method has been developed, and some calculation examples are illustrated. Analysis results show that the method can give satisfying prediction of wave loads. 相似文献
82.
文章阐述了柴油机电子调速器可靠性质量指标的重要性,提出了可靠性设计是提高电子调速器可靠性的基础,并具体地介绍了柴油机电子调速器的可靠性设计,采用裕度设计,降额设计,保护电路设计和耐振设计等技术措施,多年的实际应用证明,其可靠性是能够得到了分保证的。 相似文献
83.
TFJC-99型驼峰信号微机监测系统 总被引:2,自引:0,他引:2
TFJC-99型驼峰信号微机监测系统的研制意义,监测范围,主要功能,总的结构设计。 相似文献
84.
85.
公路T形梁预制中,梁体漏浆、气泡、水纹严重影响外观质量。结合现场制梁的施工实践,简要分析了外观质量问题的产生原因,介绍了施工生产中采取的预防漏浆、气泡、水纹的控制措施。 相似文献
86.
本文采用ansys和ansoft软件进行多相感应电机短距和整距的电磁场分析,得出多相电机设计的有益结论,并通过试验验证电磁场计算的准确性. 相似文献
87.
The wind pressure distribution and wind-induced vibration responses of long-span spatial groined latticed vaults (SGLVs) were numerically simulated, which always are ones of the most important problems in the structural wind resistance design. Incompressible visco-fluid model was introduced, and the standard k-εtwo equation model and semi-implicit method for pressure linked equation (SIMPLE) were used to describe the flow turbulence. Furthermore, the structural dynamic equation was set up, which is solved by Newmark-β method. And several sort of wind-induced vibration coefficients such as the wind-induced vibration coefficient corresponding to the nodal displacement responses and wind loads were suggested. In the numerical simulation where the SGLV consisting of the cylindrical sectors with different curved surface was chosen as the example,the influence on the relative wind pressure distribution and structural wind-induced vibration responses of the closed or open SGLV caused by such parameters as the number of cylindrical sectors, structural curvature and the ratio of rise to span was investigated. Finally, some useful conclusions on the local wind pressure distribution on the structural surface and the wind-induced vibration coefficients of SGLV were developed. 相似文献
88.
The smoothed particle hydrodynamics (SPH), as a fully Lagrangian particle method, has been successfully applied to astrophysical problems and extended to elastic dynamics and computational fluid dynamics.High order derivatives have to be approximated when elastic dynamics problems are modeled. However, the approximation errors in SPH could lead to computational failure in the case that the order of derivative is high.A novel method was proposed in order to improve the accuracy of SPH method, which shows the relationship between the selected functions and their SPH approximations. The entire involved system was represented by a finite number of particles that carry individual mass and occupy individual space, and the integral interpolation was approximated by a summation interpolation. In addition, error comparison was made between SPH method with and without the present improvement. 相似文献
89.
当前,世界制造业正加速由发达国家向发展中国家转移。面对机遇,如何制定有效的技术引进模式,有选择、有重点地引进先进技术,加快半岛制造业基地的建设,成为一个重要的战略问题。本文对山东半岛制造业基地技术引进的模式进行了探讨,并提出了相应的策略。 相似文献
90.
基于通信的移动闭塞列车控制系统 总被引:2,自引:0,他引:2
随着计算机和通信技术的发展,城市轨道交通信号系统也在不断地发展。自上世纪90年代以来,基于通信的移动闭塞列车控制系统CBTC(Corn-munication-Based Train Contro1)受到了日益广泛的重视。CBTC系统是利用列车和地面间的双向数据通信设备,使地面信号设备可以得到每一列车连续的位置信息,并据此计算出每一列车的运行权限,动态更新发送到列车,列车根据接收到的运行权限和自身的运行状态,[第一段] 相似文献