基于单位荷载法的大跨度钢屋架有限元计算及标准化设计

Finite element calculation and standardization design of large-span steel roof truss based on unit load method

随着机组的不断增大,钢结构主厂房越来越多地被使用.在电厂主厂房结构设计中,常常将屋盖钢桁架简化为等代钢梁建立空间框架计算模型,屋盖系统则独立进行详细设计.首先从常见屋架的形式及特点出发,指出屋架在内力计算时要注意的要点及控制条件.利用STAAD/CHINA有限元软件,针对某2×1 000 MW机组的跨度为31m的大跨度桁架式钢屋架进行有限元计算.在程序计算中,基于单位荷载法,重新对作用于钢桁架的荷载进行分类,简化STD文件基本荷载输入,并利用Microsoft Office软件创建标准化荷载组合,为钢桁架STAAD模型荷载及其组合的标准化设计提供了新思路.

Steel main buildings are more and more widely used in power plants with the increase of power unit.In the design of main buildings in power plants the steel truss of the roof is usually simplified as steel beams in the spatial frame model;while the roof itself should be designed alone in detail.This paper firstly introduced styles and specifics of some common roof trusses.A large-span roof truss in 2×1 000 MW project is designed with STAAD/CHINA.In the calculation process,this paper introduces the experience of load reclassification based on unit load method to simplify the basic loads’input of STD file.Standardized load combinations are created with Microsoft Office software.A new approach to standardization of STAAD model loads and their combinations for steel truss is fully shared in this article.