50m预应力T梁横向移动

通过对延水关黄河大桥工程30片50m后张法预应力混凝土T梁横向移梁方案的分析、论证与加固措施的计算,提出50mT梁横向移动方案,并付诸实施.     

Finite Element Simulation of Processes Involving Moving Heat Sources. Application to Welding and Surface Treatment

IntroductionAwiderangeofweldingorsurfacetreatmentprocessesinvolvetheuseofaheatsourcemovingataconstantspeedoverthesurfaceofthecomPonent.ThreedimensionalcomPutationofresidualstressesanddistortionsinducedbythiskindofprocesses,usingtheusualfiniteelementmethod,needsveryrefinedmeshesinordertocorrectlydescribethepropertiesandstressgradientsintheheataffCctCdzonealongthepathoftheheatsource.Inthispaper,wediscussthedifferentnumericalaPproaches,imPlementedinSYSWELD@software,whichcanbeusedtodorealisti…     

浅谈轨道交通车-地通信技术

介绍城市轨道交通车-地通信技术在铁道信号系统中的应用与发展,着重介绍城市轨道交通车-地通信的发展过程和方向,并进行相应的比较。     

移动闭塞制式信号系统结构比较

介绍了中央集中式和区域分散式的移动闭塞制式信号系统的主要特点和运营情况,并对这2种结构形式进行了比较分析。     

移动闭塞模式下越江区间列车最小追踪间隔研究

分析了越江区间内列车按移动闭塞方式行车的区间最小追踪间隔。探讨了在移动闭塞系统下风井设置与列车最小追踪间隔的关系,根据实际工程牵引计算进行校验。     

移动闭塞条件下的ATO子系统运行控制算法分析

基于移动闭塞技术的ATC系统是城市轨道交通信号系统的发展趋势,其中ATO子系统是实现城轨高效率、低能耗、高舒适度的关键技术。通过对多种智能控制算法的特点分析,指出采用不同算法的ATO子系统在实现其功能的过程中各有其不同优势侧重点。并提出可结合多种智能算法的优势实现对ATO子系统的进一步优化。     

舰载猎雷声纳基阵动力学特性研究

研究动基座上捷联式猎雷声纳基阵的动力学特性，首先给出声纳基阵的动力学模型，考虑声纳基阵的三轴框架结构特点及猎雷艇这一动基座的存在，着重对声纳基阵的动力学特性进行深入的分析和研究，揭示出其时变、非线性、强耦合的动力学特性，同时指出惯量矩阵的特殊性质，计算机仿真结果表明了理论分析的正确性。分析结果对于掌握系统本质，设计高精度，强鲁棒性的声纳基阵控制稳定系统提供了理论依据。     

Finite-volume simulation method to predict the performance of a sailing boat

 A flow-simulation method was developed to predict the performance of a sailing boat in unsteady motion on a free surface. The method is based on the time-marching, finite-volume method and the moving grid technique, including consideration of the free surface and the deformation of the under-water shape of the boat due to its arbitrary motion. The equation of motion with six degrees of freedom is solved by the use of the fluid-dynamic forces and moments obtained from the flow simulation. The sailing conditions of the boat are virtually realized by combining the simulations of water-flow and the motion of the boat. The availability is demonstrated by calculations of the steady advancing, rolling, and maneuvering motions of International America's Cup Class (IACC) sailing boats. Received: December 25, 2001 / Accepted: March 26, 2002     

Hydrodynamic modelling of a multi-body wave energy converter using the Moving Frame Method

Significant wave energy conversion may be achieved with multiple floats with several modes of motion combining constructively to generate power. With the M4 system, power take off is at hinges to absorb resulting pitch motions. Complexity increases with number of floats and conventional vectorial multi-body dynamics may be conveniently replaced by the recently formulated moving frame method based on the calculus of variations to avoid free-body diagrams and joint reaction forces. Furthermore by utilising group theory to gather spatial rotations and angular velocities in a common structure, the obtained notation is general and straight-forward to apply for single and multi-body systems. This paper lays the foundations for incorporating hydrodynamic forces into the moving frame method. The method is applied to 3, 6 and 8 float cases in regular and irregular waves with results compared to the vectorial method and experimental measurements, showing close agreement. It is suggested that this is a more natural and general approach for complex multi-body, multi-hinge hydrodynamics systems.