In the present work is proposed a methodology for parametric modeling of a bolted joint including four separate components, each of which is described with tabular dimensions according to current standard. The parametric model can automatically create a bolted assembly unit with a selected fastening size used for creating metal construction and bigger assemblies. Solutions are performed for the bolted joints used mostly in the industry.

In the present work, a study has been conducted on the possible kinematic configurations of a given gear mechanism with intermeshing satellites to compare the values of the transmitted torques. As a result of this analysis, principal schemes of compound epicyclic gear mechanisms achieving high values of transmitted torques at the output have been proposed. Kinematic synthesis of the mechanisms with optimal gear ratios achieving the highest values of output torques has been performed.

This study presents an in-depth kinematic and dynamic analysis of an epicyclic gear mechanism with mutually engaged satellites, aiming to optimize its characteristics and overall efficiency. The primary objective is to analyze its operational performance and propose optimization solutions to enhance its effectiveness. The research focuses on the complex interactions between the satellites, which ensure even load distribution, reduce localized stresses, and increase load capacity. Key parameters of the gears, including the shape of the involute profile, have been analyzed to minimize wear and extend the service life of the mechanism. Mathematical models based on the finite element method (FEM) were utilized to conduct simulations that illustrate the impact of various loads and operating conditions on the mechanism's durability and performance. Additionally, simulations conducted in the CAD environment of SolidWorks allowed for the optimization of the gear design and other system components, achieving significant efficiency under high-load operating conditions. The results indicate that this type of mechanism is particularly suitable for applications in industries such as automotive engineering, aerospace technology, and the energy sector, where reliability, durability, and precision in operational processes are of critical importance.

This study develops an analytical description of the motion of dilute solid particles in the boundary layer of laminar horizontal flows subjected to weak transverse pulsations. The analysis is formulated for dilute spherical solid particles subjected to transverse velocity pulsations in a laminar boundary-layer flow. A coupled matrix representation of the governing equations is formulated, and closed-form solutions are obtained using Laplace transformation. The analytical expressions capture transient evolution, forced oscillations, resonance effects, and long-term behaviour for particles with different density ratios. Numerical evaluation shows that light particles migrate toward faster regions of the boundary layer and accelerate longitudinally, while heavy particles move toward slower layers and decelerate. Transverse pulsations generate oscillatory trajectories whose amplitude increases near resonance. Impulsive perturbations superimposed on the continuous motion lead to discontinuous transitions consistent with the linear matrix system. The results provide a unified physical interpretation of particle redistribution mechanisms in boundary layers and offer a compact analytical tool for dilute multiphase flow modelling.

This paper presents a reliability-oriented analytical framework for the quantitative assessment of fragment-resistant multilayer protective equipment subjected to impulsive fragment loading. The study is motivated by the stochastic nature of fragment generation and impact conditions in industrial and occupational accident scenarios, where deterministic penetration criteria are insufficient to describe protective performance. Fragment interactions are modelled as stochastic spatial events, with impact locations and kinematic characteristics treated as random variables and mapped onto a predefined protected region. System failure is formulated using an energy-based limit-state criterion defined by comparison between the absorbed energy demand induced by fragment impact and a critical admissible energy threshold. The fragment–PPE interaction is described using a reduced-order dynamic formulation with concentrated parameters, capturing the dominant normal deformation response under short-duration impulsive loading. Closed-form analytical expressions are derived that relate fragment mass and velocity to impact impulse and absorbed energy. The resulting formulation establishes a direct link between impulse-driven dynamic response, progressive multilayer engagement, and failure probability under single and repeated impact events. Application of the proposed framework to a representative multilayer protective configuration demonstrates physically consistent reliability trends and confirms its computational efficiency. The framework provides a practical tool for reliability-informed assessment and preliminary design of fragment-resistant multilayer protective equipment.