Deploying Properties of Para-Cylinder with Side Polygonal Elements and Its Application to Simple Actuator

通过对由侧三角形构件组成的可折叠准圆柱展开试验，研究了侧三角形构件的形状、布置方式、折缝长度和侧构件周向数等几何参数对完全展开时的展开方式、展开速度、内压和最大载荷的影响。在侧梁展开过程中的应变也分析检查。主要结果如下：1.通过对纸张的实际折叠，发现水平折叠、螺旋折叠和重复螺旋折叠三种不同的折叠方式都可以形成可折叠的准圆柱体。当平行圆柱完全折叠时，圆柱的横截面变成各种形状.考虑桁架构件代替圆柱体侧边的折痕，解析地估计了构件的应变。分析结果表明，具有螺旋折叠方式的准圆柱展开时的应变远小于其他两种折叠方式的准圆柱展开时的应变。对于折叠后的仿圆柱体横截面上多边形边的个数N，由于桁架构件的应变较小，所以N较大的圆柱体是优选的.对各种可折叠准圆柱体的扩张实验结果与桁架杆件应变分析的预测结果吻合较好。在实验中显示出最大可展开有效载荷的准圆柱体是具有螺旋折叠的圆柱体，N = 9。在实验范围内，这种可折叠圆柱体可能是简单驱动器的最佳选择。

In this study, a series of expanding tests for some foldable para-cylinders which consist of side triangular members were carried out to investigate the influences of the geometrical parameters such as the shape and the arrangement of side triangular members, the length of creases and the circumferential number of the side members on the unfolding manner, the expanding speed, the inside pressure and the maximum payload during perfect unfolding. The strain in the side members during unfolding is also examined analytically. The principal results obtained are as follows:1. By folding a paper actually, it was found that three different types of folding, horizontal folding spiral folding and repeated spiral folding, can make a foldable para-cylinder. When the para-cylinders were perfectly folded, the cross section of the cylinders become various polygons.2. Considering truss members instead of the creases on the side of a cylinder, the strains of members were estimates analytically. The analysis results showed that the strains of para-cylinders with spiral folding during unfolding are much smaller than those of cylinders with other two folding manners. Concerning the number of the polygon side which appears in the cross-section of the para-cylinder folded, N, the cylinder with larger N is preferred because of smaller strain in the truss members.3. The results of expanding experiments for various foldable para-cylinders agreed well with the prediction by the strain analysis of truss members. The para-cylinder which showed the largest deployable payload in the experiments is a cylinder with spiral folding and N = 9. In the range of experiments, this foldable cylinder may be the best choice for a simple actuator.