Bone Stress-Strain State Evaluation Using CT Based FEM

Abstract

Nowadays, the use of a digital prototype in numerical modeling is one of the main approaches to calculating the elements of an inhomogeneous structure under the influence of external forces. The article considers a finite element analysis method based on computed tomography data. The calculations used a three-dimensional isoparametric finite element of a continuous medium developed by the authors with a linear approximation, based on weighted integration of the local stiffness matrix. The purpose of this study is to describe a general algorithm for constructing a numerical model that allows static calculation of objects with a porous structure according to its computed tomography data. Numerical modeling was carried out using kinematic boundary conditions. To evaluate the results obtained, computational and postprocessor grids were introduced. The qualitative assessment of the modeling data was based on the normalized error. Three-point bending of bone specimens of the pig forelimbs was considered as a model problem. The numerical simulation results were compared with the data obtained from a physical experiment. The relative error ranged from 3 to 15%, and the crack location, determined by the physical experiment, corresponded to the area where the ultimate strength values were exceeded, determined by numerical modeling. The results obtained reflect not only the effectiveness of the proposed approach, but also the agreement with experimental data. This method turned out to be relatively non-resource-intensive and time-efficient.

The use of X-Ray computed tomography for the diagnosis of composite structures in the energy sector

“…Одним из современных методов неразрушающего контроля композитных материалов является рентгеновская компьютерная томография (РКТ) [12][13][14][15]. Суть метода заключается в реконструкции отдельного сечения исследуемого объекта по проекционным данным, полученным при просвечивании объекта рентгеновскими лучами в различных направлениях и путем измерения энергии прошедшего излучения вдоль каждого из них.…”

Nonlinear calculation of structural elements according to transforming design schemes

“…Number of works are devoted to the study of elastic-plastic deformation of elements of three-dimensional structures. Classic examples include monographs [1][2][3][4][5][6] and articles [7][8][9][10][11][12][13][14][15][16][17][18][19]. Three elongation strains and three shear strain components are taken as strains, which are called "true" strains in the research.…”

Contact interaction of deformable continuous media of various physical nature

“…From an algorithmic point of view, the simplest method is based on calculating the coefficients of mutual influence of points of contacting bodies in the normal and tangential directions. In a number of works, contact mechanics was considered by analogy with plastic flow [9][10][11][12][13][14][15][16][17], where the analogy between the laws of plastic flow and the laws of motion of rigid or elastic blocks with dry friction was used.…”