张拉结构初始几何形状确定的形函数方法

提出了一个确定张拉结构初始几何形状的形状函数.基于该形状函数,通过对结构边界控制点的插值确定张拉结构的初始形状.该结构形状可随结构的双向张力比和边界控制点的坐标而进行自动调整.从而给出了几何上可行,力学上合理的高精度张拉曲面.通过有限元方法检查,大量例子表明该方法确定的初始形状对于实际常用边界及双向等拉或不等拉张结构均十分理想,误差很小.

A Form Function Method for Form Finding of Tension Structure

A new form function involving parameters B i is presented.On the basis of the form function,an initial form of tension structure was found by interpolating through the control points on boundary of the structure.The form function can be controlled by changing Biaccording to the pretension and the boundary of the structure.The final form of a tension structure should be an equilibrium system under the pretension.To axamine the nature of the initial form,the FEM was used.Many examples show that the initial form gives a very ideal result for equal or unequal pretension in two directions of the structure.In general cases,there is little difference between the initial form and the final one.