| Abstract | Razvojem novih, modernih tehnologija sve se više unaprjeđuje izobrazba liječnika i liječenje pacijenata. Upotreba numeričkih metoda, poput metode konačnih elemenata i računalne dinamike fluida te korištenje računalnih simulacija, značajno doprinose napretku u istraživanju i razumijevanju ponašanja bioloških sustava. Poseban doprinos biomehanici dala je aditivna tehnologija, poznatija kao 3D ispis, koja omogućuje brzu izradu prototipova te njihovog eksperimentalnog ispitivanja.
Krvožilni sustav, te bolesti vezane uz njega, jedno je od proučavanijih područja biomehanike. Kako bi se bolje razumjeli uzroci i posljedice bolesti krvnih žila provode se brojna ispitivanja s ciljem određivanja mehaničkih svojstava arterija. Glavni konstituenti stijenke arterija su kolagenska vlakna i elastinska matrica. U ovom radu, njihova mehanička svojstva nastoje se oponašati upotrebnom dva polimerna materijala Neo-Hooke materijalnog modela različitih krutosti.
U prvom dijelu ovog rada opisane su osnove građe arterijske stijenke, osnovni konstituenti stijenke te njihov utjecaj na mehanička svojstva. Nakon toga opisane su teorijske osnove mehanike kontinuuma i dan je kratki opis korištenog materijalnog modela.
U drugom dijelu opisan je postupak provedbe numeričke analize. Model se sastoji od zavojnice, koja predstavlja kolagen, koja je umetnuta u matricu, koja predstavlja elastin. Definirana su tri različita koncepta matricekojima se želio proučiti utjecaj matricena ponašanje modela. Proučavalo se kako povećanje volumnog udjela matrice utječe na iznose naprezanja modela i na krivulju naprezanja. Postavljanje numeričke analize opisano je korak po korak, definiranje materijala, postavljanje rubnih uvjeta, meshiranje modela. U rezultatima su opisana proučavana naprezanja i za svaki je koncept prikazan utjecaj povećanja volumnog udjela matrice.
Za izradu CAD modela korišten je programski paket Solidworks 2017, dok su numeričke analize provedene u programskom paketu Abaqus. |
| Abstract (english) | With the development of new, modern technologies, education of doctors and patient treatment are increasingly being improved. The use of numerical methods, such as finite element method and computational fluid dynamics, and the use of computer simulations, significantly contribute to advancesin the study and understanding of the behavior of biological systems. A special contribution to biomechanics has been made by additive technology, known as 3D printing, which enables rapid prototyping and experimental testing.
The cardiovascular system, and its related diseases, is one of the most studied areas of biomechanics. In order to better understand the causes and consequences of vascular disease, a number of tests have been conducted to determine the mechanical properties of the arteries. The major constituents of the arterial wall are collagen fibers and the elastin matrix. In this paper, their mechanical properties are sought to be mimicked by the use of two polymeric materials of the Neo-Hooke material model of different rigidity.
The first part of this paper describes the basics of the arterial wall structure, the basic constituents of the wall, and their effect on mechanical properties. The theoretical basics of continuum mechanics are then described and a brief description of the material model used.
The second part describes the procedure for performing numerical analysis. The model consists of a spiral, which represents collagen, which is inserted into the matrix, which represents elastin. Three different matrix concepts were defined to study the influence of the matrix on model behavior. It has been studied how increasing the volume fraction of the matrix affects the stress amounts of the model and the stress curve. Setting up a numerical analysis is described step by step, defining the material, setting boundary conditions, meshing the model. The results describe the studied stresses and the effect of increasing the volume fraction of the matrix is shown for each concept.
Solidworks 2017 software was used to create the CAD model, while numerical analyzes were performed in theAbaqus software package. |
