Study on the relaxation behavior of bamboo fiber as a function of temperature and moisture content

Abstract

The tensile relaxation behavior of bamboo fiber was evaluated. Bamboo fibers were extracted via a mechanical method and treated in alkaline solutions of sodium hydroxide. The relaxation tests of bamboo fibers were conducted by applying a constant strain at one end of a single bamboo fiber while the other end was fixed. The reaction force in the bamboo fiber was measured at the same time. The relaxation tests of the bamboo fibers were conducted under different temperature and moisture contents. The results showed that in the wet and/or high temperature conditions, the relaxation rate was faster than that in the dry and/or room temperature conditions. For a low strain, the bamboo fiber can be totally relaxed within 10 min under a high temperature. A nonlinear viscoelastic constitutive model was proposed to fit the relaxation curves, which could model the stress relaxation behavior of a bamboo fiber under different temperature or moisture content conditions. Compared with the experimental data, the model gave reasonable values for the relaxation behavior of the bamboo fiber.