A study of spherical compression properties of knitted spacer fabrics Part I: Theoretical analysis

Knitted spacer fabrics have been developed into a variety of special textile products for a wide range of applications. As a type of sandwich structure, their applications are largely dependent on their compression properties. Although several experimental and theoretical studies have been carried out on their plate compression properties, their spherical compression behaviors have not been deeply studied yet. This paper reports a study of the spherical compression behavior of knitted spacer fabrics. The paper includes two parts. The first part focuses on a theoretical analysis of a spacer fabric under spherical ball compression. A theoretical model is developed to predict the spherical ball compression properties of the fabric. The non-dimensional parameters are introduced to analyze the effects of the fabric thickness and ball radius based on the theoretical relationship established between the compression force and compression strain at the maximal compression point. The analysis results reveal that the spherical compression effects decrease with increasing ball radius, and increase with increasing the fabric thickness. It is expected that this study could help us better understand the behavior of knitted spacer fabrics under spherical compression.