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Background/Aim. Medial open wedge tibial osteotomy is one of the most widely accepted method of treatment for varus knee deformity in younger patient population. Its success depends on the quality of fixation and preservation of the outer cortex of the tibia. The aim of the study was to evaluate stress distribution in five numerically designed plate configurations which can be used in open wedge tibial osteotomy. Methods. The paper describes the 3D numerical model of the tibia with 10° varus deformity correction obtained by an optical scanner ATOS. The simulation anticipated axial compressive loads of 700 N, 1 400 N and 2 100 N. We used a modification of the standard T-plate in all of the five tested models. Modalities were tested with and without a metal block, and with and without a stable angle fixation plates and screws. Software PAK was used in the analysis of stress distribution. Results. With exception for the standard T-plate configuration without the supporting block, the loads up to 1400 N did not result in critical stresses on the outer cortex of the tibia in the remaining four models. There is an objective risk of possible failure of the outer cortex and loss of correction at a load of 2100 N in all configurations. The plate model with the angle stable fixation and the supporting metal block showed the most optimal distribution of stresses on the plate-bone composite compared to other models. Conclusion. The standard T-plate configuration without supporting metal block is not sufficient to stabilize the open wedge osteotomy of the tibia. Numerical models of the angle stable T-plate and the supporting metal block achieved a favorable distribution of stresses on the bone and implant which require further biomechanical testing.

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The paper represents a solution example of a specific engineering problem using thermo-mechanical analysis. The paper provides theoretical basis of numerical solving the problem of heat conducting through continuum using the finite element method. Calculation of heat conducting using the finite element method determines the temperature field used as an input for thermo-mechanical calculation. The basic task of thermo-mechanical calculation was the identification of the cause of cracks on the powder material transport wagon. After the analysis of the wagon crack causes, repair of the cracks is suggested. Repeating of the FEM analysis on the reconstructed model confirms that the wagon satisfies the criteria of static and fatigue strength appointed by the standards. [ABSTRACT FROM AUTHOR]

Copyright of InfoM is the property of Belgrade University, Faculty of Organizational Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of InfoM is the property of Belgrade University, Faculty of Organizational Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper analysis of stress and thermal-elastic-plastic strain of the drum is performed. Influence of modified thickness, yield stress and finite element model of welded joint between pipe and drum on assessment of the remaining lifetime of the drum in the thermal power plant is analyzed. Two analyses are compared. In the first, drum is modeled by shell and by 3-D finite elements with projected geometrical and material data of drum. Then, the drum is modeled by shell and by 3-D finite elements with modified thickness and yield stress. The analysis show that detailed modeling of stress concentration zones is necessary. Adequate modeling gives lower maximal effective plastic strain and increased number of cycles and, in that case, 3-D finite elements are better comparing to shell finite elements. [ABSTRACT FROM AUTHOR]

Background/Aim. Medial open wedge tibial osteotomy is one of the most widely accepted method of treatment for varus knee deformity in younger patient population. Its success depends on the quality of fixation and preservation of the outer cortex of the tibia. The aim of the study was to evaluate stress distribution in five numerically designed plate configurations which can be used in open wedge tibial osteotomy. Methods. The paper describes the 3D numerical model of the tibia with 10° varus deformity correction obtained by an optical scanner ATOS. The simulation anticipated axial compressive loads of 700 N, 1 400 N and 2 100 N. We used a modification of the standard T-plate in all of the five tested models. Modalities were tested with and without a metal block, and with and without a stable angle fixation plates and screws. Software PAK was used in the analysis of stress distribution. Results. With exception for the standard T-plate configuration without the supporting block, the loads up to 1400 N did not result in critical stresses on the outer cortex of the tibia in the remaining four models. There is an objective risk of possible failure of the outer cortex and loss of correction at a load of 2100 N in all configurations. The plate model with the angle stable fixation and the supporting metal block showed the most optimal distribution of stresses on the plate-bone composite compared to other models. Conclusion. The standard T-plate configuration without supporting metal block is not sufficient to stabilize the open wedge osteotomy of the tibia. Numerical models of the angle stable T-plate and the supporting metal block achieved a favorable distribution of stresses on the bone and implant which require further biomechanical testing. [ABSTRACT FROM AUTHOR]