Comparison of GA-Optimized Viscoelastic Models for the Characterization of Compression Behavior of Warp-Knitted Spacer Fabrics

Masih Yousefpour,Pedram Payvandy,Mohammad Saleh Ahmadi

doi:10.1515/aut-2017-0027

Abstract

Abstract Nowadays, Warp-Knitted Spacer Fabrics (WKSF) have been widely used for many technical applications. Compressional behavior of WKSF is one of their important properties. Physical modeling is one of the solutions to predict these properties for engineered designing of WKSF. In this study, four common physical models are introduced and compared in order to simulate compressional behavior of polyester WKSF. Genetic Algorithm (GA) was applied to optimize each model parameter. The results showed that the Burger model has the highest adoption with 0.2 percent Mean Absolut Error (MAE). The effect of thickness, outer fabric structure and spacer monofilament density on viscoelastic properties of the samples were also studied.

Highlights

Spacer fabrics include two outer layers that are joined together but kept apart by a middle layer of spacer monofilaments. [1] It is a known fact that spacer fabrics offer good impact and compression properties
The results showed that lower monofilament inclination angle, higher fabric thickness, finer spacer yarn and larger size of surface structure meshes result in lower energy absorption in compression.[3]
A comparative study was performed to assess the ability of four common physical models, that is, Maxwell, Kelvin-Voigt, Standard linear and Burger models, in characterizing the compression behavior of Warp-Knitted Spacer Fabrics (WKSF) and the effect of WKSF parameters on spring and dashpot coefficients

Summary

Introduction

Spacer fabrics include two outer layers that are joined together but kept apart by a middle layer of spacer monofilaments. [1] It is a known fact that spacer fabrics offer good impact and compression properties. Liu et al studied the compression behavior of WKSF for cushioning applications They investigated the effect of different structural parameters such as monofilaments inclination angle and fineness, fabric thickness and fabric layer structure. The results showed that lower monofilament inclination angle, higher fabric thickness, finer spacer yarn and larger size of surface structure meshes result in lower energy absorption in compression.[3] Du and Hu analyzed the spherical compression properties of WKSF theoretically. They investigated the deformation shape of the WKSF under spherical compression and established a relationship between total compression force and strain at the maximal compression point. The analysis results indicated that it is better for the compressive displacement of the spacer monofilament to be in the range of the Restful Stage (third stage of compression process of the spacer monofilament) to ensure a good feeling for the wearer.[7]

Objectives

Results

Conclusion