船舶大型低速柴油机VIT机构研究

在船舶大型低速柴油机的管理维护过程中,其VIT机构较之于柴油机其他部件更易于出现复杂的管理状况,甚至发生设备故障,针对此现象,文章研究分析了船舶大型低速主动力柴油机的VIT机构功能调整、故障处理和维护管理技术等三个方面的难点问题,提出了相应的预防措施和解决方案,为广大同行提供借鉴。     

陡坡斜井中隔墙快速施工技术

雅泸高速公路大相岭隧道2#通风斜井斜距长、坡度大,担负着正线隧道运营通风的繁重任务。通过对斜坡道上中隔墙施工的实践论证,本工程选择了分离式中隔墙模板台车,以及由2 t慢速卷扬机和3×4滑轮组组成的牵引系统的快速施工技术,从而加快了分离式中隔墙模板台车的移动和定位,保证了施工进度,减少了工程投资,取得了良好的经济效益及社会效益。     

武汉市杨泗港快速通道转体斜拉桥设计

武汉市杨泗港快速通道转体斜拉桥为我国首座半漂浮体系独柱塔转体斜拉桥,孔跨布置为(40+88+252+88+40) m。主桥按双向八车道设计并考虑两侧设置人行道,转体质量约1. 75万t,转体半径124 m。主梁为整幅钢箱梁,采用中央双索面,桥塔为独柱形钢筋混凝土结构,斜拉索采用高强度平行钢丝。对主桥地理位置、桥型方案选择、结构设计构造及计算分析进行详细阐述,使用有限元软件对主桥进行整体静力计算、转体结构计算、抗震分析及稳定分析。计算结果表明:本桥各构件受力良好,结构安全可靠,桥梁具有良好的静动力性能。独柱宽幅中央索面转体钢箱梁斜拉桥具有良好的经济性和美观性,可为上跨铁路桥梁桥式方案提供借鉴并可进一步推广。     

Design of central symmetric lattice structure for ocean engineering based on fluid-solid-interaction

Some structures that constitute underwater vehicles and other ocean engineering structures, such as the shell of underwater vehicles, shafting of power systems, compressor impellers and propeller hubs, all have central symmetric or rotationally symmetric cross sections. In this paper, a kind of central symmetric lattice is designed. The lightweight design of the above structure with this lattice can significantly reduce the weight of the structure on the premise of reducing the static response of the structure. Combined with the ANSYS Parameter Design Language (APDL), the homogenization method is used to analyze the static response of the rotationally symmetric lattice structure and the parallel pattern lattice structure under pressure. The fluid load (pressure) of impeller is calculated by CFX. The results show that the structural stress of the central symmetric lattice structures with the same volume fraction is smaller than that of parallel pattern lattice under the same load when the rotationally symmetric structures have the same form. The application of the homogenization method proves that the above conclusions also improve the efficiency of the static response calculation of the central symmetric lattice structure. The design and research methods in this paper provide technical support for the realization of lightweight design of small and medium-sized underwater rotationally symmetric structures.