Analyzing deformations in fiber-reinforced soft membranes undergoing axisymmetric inflation: Continuum model and experimental validation

Abstract

By incorporating arrays of nearly inextensible fibers into soft membranes capable of undergoing large strains, this research explores the impact of these fibers on the deformations occurring during axisymmetric inflation. Our investigation focuses on the influence of various fiber configurations on the resulting deformed shapes. These fibers exhibit high stiffness in extension while offering minimal resistance to bending, allowing them to reorient freely upon deformation and thereby induce distinctive deformations under simple loading conditions. To predict and understand these deformations, we present a continuum model for hyperelastic membranes in generalized curvilinear coordinates, allowing for arbitrary fiber orientations, thus enhancing its adaptability to diverse configurations. Through experimental validation across multiple fiber configurations, we demonstrate the model’s accuracy in predicting deformations and showcase how the initial fiber orientation can be leveraged to create different motion patterns. We present two such motion patterns—one capable of azimuthal shear and another emphasizing extension. This study offers valuable insights for the integration of fiber reinforcement into soft morphing surfaces, with particular relevance to applications in robotics and beyond.