{"title":"A thermal-mechanical coupling-inspired inelastic constitutive law for the growth and atrophy of biological soft tissues","authors":"Jike Han , Yuka Yokoyama , Taiji Adachi , Shinji Nishiwaki","doi":"10.1016/j.jmps.2025.106159","DOIUrl":null,"url":null,"abstract":"<div><div>This study proposes a thermal-mechanical coupling-inspired inelastic constitutive law for the growth and atrophy (for the increase and decrease of volume and mass) of biological soft tissues. The thermal-mechanical coupling-inspired formulation realizes the multiphysics modeling between the mechanical field and a scalar field, say the nutrition field, that represents the transportations of the nutrition source inside of the body and the nutrition flux on the surface. Accordingly, biological soft tissues can exhibit growth and atrophy without any displacement or force loadings, which is analogous to thermal strain. On the other hand, the inelastic constitutive modeling decomposes the deformation gradient tensor into the elastic and growth components, and the evolution laws for the growth and atrophy are derived as the stationary conditions from the dissipation optimization problem, whose mathematical manipulation is the same as the standard elastoplastic material modeling. Thanks to the proposed formulation, several characteristic material responses that are seen in natural organisms are imitated. In particular, it is successfully realized that the growth and atrophy of biological soft tissues are not exclusively determined by the value of the mean stress, and can occur even under a constant compression/tension state. Also, when biological soft tissues are subjected to repeated growth and atrophy, the cellular aging-like material response occurs due to the accumulation of hardening variables, by which biological soft tissues become insensitive to external factors that encourage growth and atrophy. Two single-element level numerical examples are presented to demonstrate the basic material responses of the proposed formulation, and two structural numerical examples are prepared to show a few characteristic growth and atrophy trends that are determined by both states of the mechanical and nutrition fields.</div></div>","PeriodicalId":17331,"journal":{"name":"Journal of The Mechanics and Physics of Solids","volume":"202 ","pages":"Article 106159"},"PeriodicalIF":5.0000,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of The Mechanics and Physics of Solids","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022509625001358","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
This study proposes a thermal-mechanical coupling-inspired inelastic constitutive law for the growth and atrophy (for the increase and decrease of volume and mass) of biological soft tissues. The thermal-mechanical coupling-inspired formulation realizes the multiphysics modeling between the mechanical field and a scalar field, say the nutrition field, that represents the transportations of the nutrition source inside of the body and the nutrition flux on the surface. Accordingly, biological soft tissues can exhibit growth and atrophy without any displacement or force loadings, which is analogous to thermal strain. On the other hand, the inelastic constitutive modeling decomposes the deformation gradient tensor into the elastic and growth components, and the evolution laws for the growth and atrophy are derived as the stationary conditions from the dissipation optimization problem, whose mathematical manipulation is the same as the standard elastoplastic material modeling. Thanks to the proposed formulation, several characteristic material responses that are seen in natural organisms are imitated. In particular, it is successfully realized that the growth and atrophy of biological soft tissues are not exclusively determined by the value of the mean stress, and can occur even under a constant compression/tension state. Also, when biological soft tissues are subjected to repeated growth and atrophy, the cellular aging-like material response occurs due to the accumulation of hardening variables, by which biological soft tissues become insensitive to external factors that encourage growth and atrophy. Two single-element level numerical examples are presented to demonstrate the basic material responses of the proposed formulation, and two structural numerical examples are prepared to show a few characteristic growth and atrophy trends that are determined by both states of the mechanical and nutrition fields.
期刊介绍:
The aim of Journal of The Mechanics and Physics of Solids is to publish research of the highest quality and of lasting significance on the mechanics of solids. The scope is broad, from fundamental concepts in mechanics to the analysis of novel phenomena and applications. Solids are interpreted broadly to include both hard and soft materials as well as natural and synthetic structures. The approach can be theoretical, experimental or computational.This research activity sits within engineering science and the allied areas of applied mathematics, materials science, bio-mechanics, applied physics, and geophysics.
The Journal was founded in 1952 by Rodney Hill, who was its Editor-in-Chief until 1968. The topics of interest to the Journal evolve with developments in the subject but its basic ethos remains the same: to publish research of the highest quality relating to the mechanics of solids. Thus, emphasis is placed on the development of fundamental concepts of mechanics and novel applications of these concepts based on theoretical, experimental or computational approaches, drawing upon the various branches of engineering science and the allied areas within applied mathematics, materials science, structural engineering, applied physics, and geophysics.
The main purpose of the Journal is to foster scientific understanding of the processes of deformation and mechanical failure of all solid materials, both technological and natural, and the connections between these processes and their underlying physical mechanisms. In this sense, the content of the Journal should reflect the current state of the discipline in analysis, experimental observation, and numerical simulation. In the interest of achieving this goal, authors are encouraged to consider the significance of their contributions for the field of mechanics and the implications of their results, in addition to describing the details of their work.