Composite Material Dielectric Constant Measuring Device and Method under Stress

This paper proposes a device and method for measuring the dielectric constant of composites under stress. Based on the traditional free space measurement system, a stress loading mechanism is added to change the stress of the material. In addition, due to slight displacement of the material during stress, we also proposes a measurement method that is different from the traditional free space method. The measurement method proposed in this paper removes the impact of displacement and thickness changes on the S-parameter, and can accurately invert the relative change of the dielectric constant when the material is stressed.