Mathematical modeling of viscoelastic foam material for design of filtering respirators

Abstract

The work is devoted to the development of a mathematical model of the foam material of the filtering half mask. The analysis of the methods used to study the leveling of the negative effect of the compression pressure of the filtering half-mask on the soft tissues of the human face under conditions of long-term operation was carried out. In order to study the mutual influence in the medium "filter material - foam material - human soft tissues", it is proposed to conduct virtual tests using numerical methods. The development of mathematical models of linear viscoelastic materials is based on the study of the relationship between the input and output characteristics of viscoelastic materials: stress and strain. The paper is devoted to the development of the mathematical model of linear viscoelastic materials using a transfer function. The model is designed to investigate the relationship between stress and deformation in viscoelastic materials using numerical methods.

Study of friction in the "textile-human" system for the ergonomic design of sustainable functional clothing

“…It should be noted that, in practice, frictional interaction is of a complex nature due to the intermolecular interaction of the contacting surfaces (adhesion component) [9,10]. Knitted fabrics have a non-uniform rough surface, which can be represented as alternating protuberances and cavities, depending on the structural characteristics of the weave, as well as non-alternating (random) formations in the form of pills, fibre particles, etc.…”

“…It is worth noting that the surface of the body has some features of the geometric structure and physico-mechanical properties [9,10].…”

“…The internal structure of the human body is multicomponent and it is not an easy task to spot the influence of the physico-mechanical properties of the internal elements on the outer shell (the surface of the human skin). For an accurate complex estimation, it is expedient to carry out finite element analysis [9]. The finite element method is based on setting the properties of the materials of the structural elements of the stress-strain body, the actuating forces (gravitational acceleration, pressure, various loads and restraints) as well as interfacial conditions, then a numerical solving is made in the variational formulation or in the form of a system of partial differential equation [10][11][12].…”

Biomechanics of the human upper limb for sustainable approach to design smart clothing

“…The location points of the most comfortable topographic zones represent the following functional relationship: FARCS, ADF, ADB (xi, yi) =  (l1, , , , , ), (1) where xiis the horizontal coordinate (level), yiis the vertical coordinate (level), l1is the length of the human arm,  -is the angle at the elbow joint,  -is the angle of displacement of the shoulder joint in the sagittal plane,  -is the angle at the wrist joint in the frontal plane,  -angle in the wrist joint in the sagittal plane,  -angle of pronationsupination rotation. FARCD (xi, yi) =  (l1, , , , , , ), (2) where  -angle of torso in the sagittal plane.…”

“…The traditional purpose of clothing is protection of human body from cold, nudity; comfortable wearing with functional construction and decorative elements; visual appearance based on social aesthetic standards [1]. At the same time, the purpose of clothing and its functional features are constantly expanding due to changes occurring in the socio-cultural environment, the information environment, thanks to achievements in the field of scientific developments in the field of micro-and nanoelectronics, information and biotechnologies [2][3].…”