Transverse tensile mechanical experimental method and behavior of ceramic matrix mini-composites

Abstract

Transverse tensile mechanical experiments of ceramic matrix mini-composites (CMMC) were realized in this paper by overcoming the difficulties from material preparation, specimen design, gripping method, loading strategy, deformation measurement, transverse tensile stress calculation, etc. The transverse tensile stress-strain responses were obtained based on the proposed method. The stress-strain response was strongly non-linear, and its elastic modulus was positively correlated to the matrix volume fraction. The digital image correlation (DIC) was utilized in the experiment. The staged transverse tensile strain field evolution process was analyzed. The crack initiation and propagation could be clearly captured by the strain field contour. In addition, a novel DIC data analysis strategy was applied to investigate the uniformity variation of the transverse tensile strain field. This paper found that the strain field uniformity has a strong correlation with the damage extent and can be used to reflect the damage evolution of the material sensitively. The relationship between local damage and overall mechanical responses, and the localization and non-uniformity characteristics of damage evolution were also discussed. The impact of microstructure on transverse tensile elastic modulus was analyzed, and a model that considered the microstructure was built to predict CMMC’s transverse tensile elastic modulus.