水泥厂大跨度空间网壳结构设计方案研究

目前水泥厂石灰石预均化库用到的空间网壳结构最大跨度为98m,为适应水泥厂建设规模不断扩大的发展要求,跨度超过100m的空间网壳结构将成为今后结构设计的趋势.本文在分析了单层网壳、双层网壳、弦支穹顶等常规结构体系应用的局限性后,着重分析了适应大跨度要求的多层网壳结构体系,并提出了主从网壳结构体系的概念.根据以往石灰石预均化库的设计要求,分别对150m、200m和300m跨度的屋盖采用双层网壳、三层网壳、主从网壳等三种结构体系,进行静力分析并对其静力特性、经济指标等进行了比较分析.研究表明,跨度150m以上结构不推荐使用单层网壳,可以采用双层网壳或主(双)从(单)网壳;跨度200m的结构使用双层网壳可以节省钢材量,但螺栓直径有可能超过常规螺栓直径的最大规格而需要使用昂贵的大直径螺栓,而三层网壳具有杆件长度小、杆件截面尺寸小、整体刚度大、内力峰值低、螺栓和螺栓球直径小等优点,更能适应大跨度网壳的要求;跨度300m的结构使用三层网壳和主从网壳结构体系,而后者在用钢量上更占优势.

Healing Temperature of Hybrid Structures Based on Genetic Algorithm

The healing temperature of suspen-dome with stacked arches(SDSA)and arch-supported single-layer lattice shell structures was investigated based on the genetic algorithm. The temperature field of arch under solar radiation was derived by FLUENT to investigate the influence of solar radiation on the determination of the healing temperature. Moreover, a multi-scale model was established to apply the complex temperature field under solar radiation. The change in the mechanical response of these two kinds of structures with the healing temperature was discussed. It can be concluded that solar radiation has great influence on the healing temperature, and the genetic algorithm can be effectively used in the optimization of the healing temperature for hybrid structures.

凉都体育中心体育馆屋盖风振效应研究

以凉都体育中心体育馆为背景,通过谐波叠加法分别得到屋盖关键点的具有Davenport谱和Panofsky谱功率特征的水平和竖向风速时程,将风速时程转化为风压时程,结合前期CFD分析得到的风压系数对体育馆屋盖钢结构进行有限元时程响应分析,得到体育馆屋盖钢结构各处的风振响应。研究发现,相距较近且体量相似的建筑,相互在风压分布方面有较大影响,导致结构在不同的风向角下具有不同的风振系数,因而结构设计中应综合考虑各方向下风振效应以确定风振系数;凉都体育馆及类似的多层网壳结构刚度较大,同时风振较为明显的部分为网壳边缘靠上环向区域,屋盖平均风振系数可取1.7。