International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This work presents a numerical Finite Element Modeling of mechanical behavior of a human vein under influence of medical compression sock. The FE Model is developed in form of structural transient analysis by help of program product Ansys. The geometry of the vein and the muscle is assumed as an idealized, and consists of two coaxial cylinders. The stocking pressure is translated to the vein through the muscles contractions, surrounding tissues and the skin. Moreover, such a pressure and its variations, as well the position of the vein in the muscle environment, should also have influence on the functioning of venous valves and on the lymphatic system drainage. Because of preliminary character of this elaboration, these aspects are not discussed here.
The work set-up aims to establish principally how the stocking pressure loads the vein wall depending on different venous elasticity under given constant muscle elasticity.
The mechanical behavior of vein possessing elastic module E=30kPa and 100kPa is considered under stocking pressure Pst=25mmHg and 60.8mmHg and muscle tissue with elastic module Em=12kPa. The displacements in the vein and muscle with corresponded distributions of stress and strain states are identified in the both two elements.
It is concluded, that these two pressures induce similar stress values in the vein walls depending on the two venous elastic modules, correspondingly. Based on that, it is suggested that a 3-Dimensional space of the geometry, pressure and the elastic modules could be existed. In such a space, optimal patient-orientated values of the pressure depending on the geometrical sizes and elasticity should be available.

Laser Powder Bed Fusion (LPBF) is a prominent additive manufacturing process used for fabricating complex metallic structures, but it often encounters challenges related to thermal distortions and residual stresses, particularly in thin-walled structures. These issues compromise the integrity and dimensional accuracy of the parts. Finite Element Analysis (FEA) has been essential in simulating and understanding the thermal and mechanical behaviors during the LPBF process. This study focuses on validating a refined FEA model developed using ANSYS Additive Print (AAP) to predict the thermal distortions in CoCr thin-wall structures. The validation involves comparing simulation results with experimental data to verify the model’s effectiveness. The study demonstrates the integration of advanced simulation techniques in predicting distortions and stresses, thereby enhancing the reliability and accuracy of the manufacturing process.

This elaboration proposes results obtained during initial stages of numerical modeling of the function of aortic heart valve depending on its elastic module and the aortic elastic module.
The actuality of such an elaboration could be based on the advancing progress in the material sciences, as well as on the increasing opportunities given by the development of the medical diagnostic technics for observation of processes in the human organism and the development of computational technics.
The work and the interactions between the aortic valve and the aorta is here structurally modeled according to Finite Element Method by help of Ansys commercial product. Elastic material models are assumed for the materials of aorta and aortic valve. The geometry of the aortic valve and the aorta are designed as averaged ones according to suggested reference data. The boundary conditions are assumed according to reference data about left-ventricle blood pressure and the aortic blood pressure. These material models, geometry and boundary conditions could be reformulated according each separately given case. That will give possibilities of development of the subject of this work following as called patient-orientated model.
The displacements, the stress and strain distributions in both aorta and valve are established depending on both blood pressures aortic and left-ventricle depending on two aortic elastic modules 0.476 and 1MPa under elastic modules of the sinotubular junction 15.34MPa and sinus of Valsalva 20.24MPa. Pumping functions of the heart and the aorta are numerically observed depending on the two aortic elasticmodules. Some variations in the elastic modules of the sinotubular junction and sinuses of Valsalva are commented.
The proposed finite element model and the obtained results could open future possibilities to enlarge this work, for example, through variations in the four elastic modules, variations in the aortic geometry also including additional branches to the aorta or modeling of interactions between pulsating blood flow and arterial-valve structures, also not excluding real experimental formulation or design and synthesis of new biological materials.

In this study, the design and modeling of a shredding unit intended to fragment nonwoven waste fabrics and prepare them for recycling were carried out. Stress analyses were performed on the shaft attached to the blade, along with motor power and torque analyses required for smooth operation, and mass flow calculations. Mathematical models were developed based on these data. Additionally, structural analyses of the chassis, necessary for stable system operation, were conducted, resulting in a comprehensive mathematical model of the entire system.

The following paper reviews all the possible cases of coupled two-carrier planetary gears with four external shafts. An emphasis is made on the work of these gears with one degree of freedom, one input and one output shaft and brakes on the other two shafts . When switching over the gears, the speed ratio of the gear is changed, thus allowing the use in two-speed mechanical transmissions of technological lifting and other machines. Some relations are deduced for determining the speed ratios and the efficiency of all structural schemes.
Recommendations for the selection of the most appropriate structural scheme according to the current necessities can be made. A 3D model of the S13V3 two-speed, two-carrier gearbox was created to demonstrate the process of determining the viability of a particular gearbox layout.

A Continuum (filled polymer) is inhomogeneous and anisotropic. The Continuum is used in an injection moulding simulation at first (generally unnewton type of fluid). Then the continuum is solid (after cooling) and it is possible to carry out ordinary dynamics structural analysis with it. The solid continuum has different mechanical properties for each of discrete element. A consequent dynamics properties (natural frequencies) will generally have different values when influence of injection moulding is taken into account for analyses.