Research on moisture absorption characterization of wound composites based on surface concentration modified model

Abstract Four groups of hygroscopic experiments of T700/epoxy composite wound rings at temperatures and humidities of 45°C/60%, 45°C/90%, 70°C/60%, and 70°C/90% were completed in order to study the moisture absorption characterization. Surface concentration correction models characterized by different types of functions such as linear, quadratic, sinusoidal, exponential, and others were proposed to establish a “three-stage” moisture absorption model, in which the initial stage was smooth, the middle stage grew rapidly, and the later stage tended to equilibrium. The theoretically predicted hygroscopic curves derived from quadratic and exponential functions were in good agreement with the experimental data, which revealed the difference in the moisture absorption characterization between the wound rings with high fiber volume and that of the laminates and fabrics and provided a basis for the prediction of the mechanical degradation and life of the wound composites in hygrothermal environments.