Lateral indentation of a reinforced braided tube with tunable stiffness

In this paper, the lateral indentation of a newly proposed reinforced braided tube with tunable stiffness, which takes a braided tube as skeleton and is sealed by thin membranes, has been studied experimentally and numerically. It is found out that the radial stiffness could be increased by 290% compared with that of a stand-alone braided tube, through adjusting the negative pressure between the braided skeleton and the membranes. During deformation, the fibers in the reinforced tube are longitudinally restricted by friction, which increases the stiffness of the braided skeleton. In addition, friction dissipation due to sliding between fibers and membranes also contributes substantially to the load carrying capability of the reinforced tube, leading to a much stiffer structure than the summation of the constituents. A parametric analysis has also been conducted, from which the effects of the design parameters are obtained. •The lateral indentation of a composite tube with tunable stiffness was studied.•The radial stiffness was improved by 290% by adjusting the negative pressure.•Two main mechanisms leading to the increased stiffness were identified and analyzed.