Large-scale deformation and damage detection of 3D printed continuous carbon fiber reinforced polymer-matrix composite structures

For the efficient monitoring regional deformation and damage of continuous carbon fiber reinforced polymermatrix composite structures, a dual-material three-dimensional printing process was developed, in which continuous carbon fiber tows were integrated within the polymer matrix to construct smart sensing grids. Strategies based on the electrical-mechanical behavior of continuous carbon fiber tow for locating loading position and recognizing deformation field distribution, as well as damage detection, have been presented. The loading location can be determined through the maximum fractional change in electrical resistance of continuous carbon fiber tows in the longitudinal and transverse direction. A model based on the electrical-mechanical behavior of carbon fiber tow has been developed to identify the deformation field distribution. Both micro-damage and macro-damage can be detected according to the dramatic change in the slope of fractional change in electrical resistance with the strain. The effectiveness of above methods has been verified through experiments.