results correspond to test results well. each analysis

result represents the characteristics of double-tubes whether satisfy the criterion or not. the applicability of the are grouped in in which the varied is the EI-series; the other the strength point of the strength and the stiffness of inner tubes for each model plotted as shown in Figure 12(a), which shows that EI3 are on the boundary of the safe region. The results the development of tearing at of the tensile brace