体内张拉成形空间网格结构试验模型成形过程分析

FORMING ANALYSIS OF MODEL FOR INTERNAL STRETCH-DRAW SPACE LATTICE STRUCTURE

体内张拉成形空间网格结构是通过几何大变形成形的预应力钢结构,施工时张拉下弦索使上弦梁拱起成形,结构成形后下弦完全水平。针对一个典型的体内张拉成形空间网格结构试验模型,分次分批施加预应力使结构成形,详细研究成形过程中结构上弦单元的变形及受力特点,分析不同批次张拉单元之间的相互影响,探索体内张拉成形空间网格结构的成形机理。研究结果表明,上弦是结构的主要受力构件,成形过程中结构不同位置上弦弯矩和轴力的变化规律不同。

The internal stretch-draw space lattice structure is a kind of pre-stressed steel structure forming with big geometrical deformation.The structure is erected by cable in the lower chord while top beam is rising and arching.Finally the lower chord is horizontal after forming the structure.A typical model of this structure is designed.The pre-stress are applied to whole structure step by step during the forming process.A series of important problems are studied including deformation characteristics and mechanical behaviors. The interactions of different parts of the structure are analyzed while the forming mechanism is explored.The results show that top beam is the major structural member.During the forming process the changes in forces and moments are different in the different parts of the top beam.