{"title":"Modeling dynamic impact, shock waves, and injury in liver tissue with a constrained mixture theory","authors":"J. D. Clayton","doi":"10.1007/s10237-025-01990-3","DOIUrl":null,"url":null,"abstract":"<div><p>A nonlinear continuum theory is advanced for high-rate mechanics and thermodynamics of liver parenchyma. The homogenized continuum is idealized as a solid–fluid mixture of dense viscoelastic tissue and liquid blood. The solid consists of a matrix material comprising the liver lobules and a collagenous fiber network. Under high loading rates pertinent to impact and blast, the velocity difference between solid and fluid is assumed negligible, leading to a constrained mixture theory. The model captures nonlinear isotropic elasticity, viscoelasticity, temperature changes from thermoelasticity and dissipation, and tissue damage, the latter via a scale-free phase-field representation. Effects of blood volume and initial constituent pressures are included. The model is implemented in 3-D finite element software. Analytical and numerical solutions for planar shock loading are compared with observations of liver trauma from shock-tube experiments. Finite-element simulations of dynamic impact are compared with cylinder drop-weight experiments. Model results, including matrix damage exceeding fiber damage at high rates and reduced mechanical stiffness with higher perfused blood volume, agree with experimental trends. Viscoelasticity is important at modest impact speeds.</p></div>","PeriodicalId":489,"journal":{"name":"Biomechanics and Modeling in Mechanobiology","volume":"24 5","pages":"1735 - 1766"},"PeriodicalIF":2.7000,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biomechanics and Modeling in Mechanobiology","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s10237-025-01990-3","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
A nonlinear continuum theory is advanced for high-rate mechanics and thermodynamics of liver parenchyma. The homogenized continuum is idealized as a solid–fluid mixture of dense viscoelastic tissue and liquid blood. The solid consists of a matrix material comprising the liver lobules and a collagenous fiber network. Under high loading rates pertinent to impact and blast, the velocity difference between solid and fluid is assumed negligible, leading to a constrained mixture theory. The model captures nonlinear isotropic elasticity, viscoelasticity, temperature changes from thermoelasticity and dissipation, and tissue damage, the latter via a scale-free phase-field representation. Effects of blood volume and initial constituent pressures are included. The model is implemented in 3-D finite element software. Analytical and numerical solutions for planar shock loading are compared with observations of liver trauma from shock-tube experiments. Finite-element simulations of dynamic impact are compared with cylinder drop-weight experiments. Model results, including matrix damage exceeding fiber damage at high rates and reduced mechanical stiffness with higher perfused blood volume, agree with experimental trends. Viscoelasticity is important at modest impact speeds.
期刊介绍:
Mechanics regulates biological processes at the molecular, cellular, tissue, organ, and organism levels. A goal of this journal is to promote basic and applied research that integrates the expanding knowledge-bases in the allied fields of biomechanics and mechanobiology. Approaches may be experimental, theoretical, or computational; they may address phenomena at the nano, micro, or macrolevels. Of particular interest are investigations that
(1) quantify the mechanical environment in which cells and matrix function in health, disease, or injury,
(2) identify and quantify mechanosensitive responses and their mechanisms,
(3) detail inter-relations between mechanics and biological processes such as growth, remodeling, adaptation, and repair, and
(4) report discoveries that advance therapeutic and diagnostic procedures.
Especially encouraged are analytical and computational models based on solid mechanics, fluid mechanics, or thermomechanics, and their interactions; also encouraged are reports of new experimental methods that expand measurement capabilities and new mathematical methods that facilitate analysis.