title: A visco-hyperelastic constitutive approach for modeling polyvinyl alcohol sponge.
abstract: This study proposes the quasi-linear viscoelastic (QLV) model to characterize the time dependent mechanical behavior of poly(vinyl alcohol) (PVA) sponges. The PVA sponges have implications in many viscoelastic soft tissues, including cartilage, liver, and kidney as an implant. However, a critical barrier to the use of the PVA sponge as tissue replacement material is a lack of sufficient study on its viscoelastic mechanical properties. In this study, the nonlinear mechanical behavior of a fabricated PVA sponge is investigated experimentally and computationally using relaxation and stress failure tests as well as finite element (FE) modeling. Hyperelastic strain energy density functions, such as Yeoh and Neo-Hookean, are used to capture the mechanical behavior of PVA sponge at ramp part, and viscoelastic model is used to describe the viscose behavior at hold part. Hyperelastic material constants are obtained and their general prediction ability is verified using FE simulations of PVA tensile experiments. The results of relaxation and stress failure tests revealed that Yeoh material model can define the mechanical behavior of PVA sponge properly compared with Neo-Hookean one. FE modeling results are also affirmed the appropriateness of Yeoh model to characterize the mechanical behavior of PVA sponge. Thus, the Yeoh model can be used in future biomechanical simulations of the spongy biomaterials. These results can be utilized to understand the viscoelastic behavior of PVA sponges and has implications for tissue engineering as scaffold.
authors.affiliation: School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16844, Iran; Tissue Engineering and Biological Systems Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16844, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Karimi
authors.affiliation: School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16844, Iran; Tissue Engineering and Biological Systems Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16844, Iran. Electronic address: mnavid@iust.ac.ir.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Navidbakhsh
authors.affiliation: School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16844, Iran.
authors.forename: Borhan
authors.initials: B
authors.lastname: Beigzadeh
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D004548:Elasticity; D008954:Models, Biological; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D019736:Prostheses and Implants; D013314:Stress, Mechanical; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D011145:Polyvinyls; C026699:ivalon sponge; D011142:Polyvinyl Alcohol
keywords: Constitutive modeling; Finite element analysis; PVA sponge; Swelling rate; Visco-hyperelastic