Simulation-based Prediction Model to Optimize Contact Pressure of Knitted Fabrics for Wearable Garments

Abstract

This paper proposes a simulation-based contact pressure (CP) prediction model for prototyping electronic textile (e-textile) wearable devices for health monitoring. This study uses a CLO 3D garment simulator, and knit fabrics are investigated in different weights and polyurethane contents. The first phase presents a comparative analysis of simulated and experimental stress. Based on the understanding of simulated stress, the CP model is developed by modifying Laplace’s law and using the simulated stress. The CP model is validated using a pressure sensor to compare the actual contact pressure. The developed CP model helps garment designers and engineers select the appropriate material and product size to achieve the target pressure required for ECG health monitoring in their decision-making.

Enhancing Biosignal Quality in Electrocardiogram Monitoring Garments: Validation of a Simulation-Based Contact Pressure Model

“…The average simulated stress or strain can be used along with the stretch stiffness in the simulation-based CP model (eq ) CP 0.25em = 0.25em ( t 2 π r ) ( ε s 0.25em × 0.25em SS ) newline = ( t 2 π r ) ( σ s 0.25em × 0.25em C ) where t is the thickness of the specimen (m), r is the radius of a cylinder (m), ε s is the measured simulation strain, σ s is the simulated stress (kPa), and SS is the stretch stiffness in the specific direction (warp, weft, or shear) obtained from the digitized physical property (g/s 2 ). The material constant ( C ) can be calculated from exp( a + b × SS + c × SS 2 ) by inserting the constants ( a , b , and c are 4.42549, −0.05652, and 3.93323e –4 , respectively). , In this study, we efficiently used simulation strain and stretch stiffness by plugging them into the CP model (eq ).…”

“…To select the appropriate compressional material for functional garment designs for the specific end-use, one must first conduct a physical tensile test to obtain the elastic modulus and then predict the contact pressure using theoretical CP models from existing literature. After selecting the right fabric based on their predictions to meet the desired CP, it is then moved on to fabric digitization and garment simulation to create functional apparel prototypes before physical production. − However, an ideal scenario would involve predicting the contact pressure directly within the simulation program. The reliance on physical tensile testing can be minimized or even eliminated by obtaining garment stress or strain data from the simulation’s mechanical property representation and converting it into actual pressure values.…”

“…This study presents a novel approach by comparing theoretical insights (uniaxial tensile test-based pressure prediction) with a simulation-based contact pressure model (CP model). Youn et al recently developed the simulation-based CP model to enhance electrocardiogram (ECG) signal quality for designing their ECG armband. , However, their study was limited to single jersey fabrics, not exploring interlock or elastane plaiting structures integral to compression garments. We extend this model to various knit structures and applications, aiming to optimize the contact pressure for enhanced biosignal quality in ECG chest bands.…”