Nowadays, press-fitting is widely used in the manufacturing industry because it allows easy and fast installation and is repetitive, strong, and inherently reliable. The quality of a press-fitting assembly can be verified from the press-fitting curves and forced monitoring. This study aims to investigate the characteristics of the press-fitting curve with various interference railway wheelset models and determine the interference limit that axles can withstand at the maximum holding torque without slipping and without plastic deformation. A three-dimensional finite element analysis examined the maximum press-fitting force and stress distributions using Abaqus FEA software. The press-fitting curves of the railway wheel and axle assembly obtained from finite element simulation were classified following European Standard EN 13260. The press-fitting curves showed whether they fell within the boundary limits in the EN standard to allow their practical application. This study also showed when plastic deformation would occur, within the recommended interferences in the EN standard. Moreover, the effect of interference was numerically simulated for the maximum holding torque capacity within the EN standard interference range. Numeric simulation was compared with the theory: the deviation was 15–6%.

Press fitting is one of the common fastening methods used to assemble mechanical components. It has also received considerable critical many industrial applications, for example, railway wheel and axle are usually assembled by press-fitting. This process generates high stress on the axle-fillet area and fatigue is generally initiated due to the stress concentration. This paper attempts to propose the stress distribution and deformation of a railway axle. Various interference clearances were analyzed using finite element method. The contact pressure at the axle wheel seat along the axial direction was examined as it significantly influences the press-fitted components life. The analytical results from Lame’s theory [1] were compared with finite element analysis results for the wheel and axle press-fitting process. The results obtained from both methods were in good agreement and the maximum relative error of the contact pressure is by 11.08 %. Additionally, the results show that the Von-Mises stresses on the axle wheel seat and fillet areas were found to be increased if the interference increased.

Fractures of the distal radius often require surgical intervention, with plate fixation being a standard stabilization method. Screw loosening and pull-out propose significant complications, necessitating comprehensive understanding of fixation stability factors. This study introduces a novel approach by the combination of finite element analysis (FEA) and experimental investigations on Thiel cadavers to evaluate screw pull-out behavior from plate fixation in en bloc distal radius resection with ulnar reconstruction. In comparison with previous investigations that used computational modeling or fresh-frozen cadaveric specimens, in the present research, FEA predictions specifically experimentally confirm the usage of Thiel cadavers, which better preserve soft tissue elasticity and hydration, thus more closely reflect in vivo conditions. Experimental set-up consisted of bending tests on cadavers and screw pull-out tests in Thiel-cadaveric radius specimens mimicking physiological conditions that induce the effects of screw pull-out. Finite element analysis and simulation were conducted using realistic clinical cases. Biomechanical test results indicated locking-plate deformation and screw loosening, particularly at locations closest to the ulnar bone gap. Torque measurements established various degrees of screw loosening, with the screws closest to the bone gap indicating maximum loosening. FEA demonstrated critical distributions of stresses in screws and locking plates, with good correlations to experimental findings. Screw pull-out force analysis showed vulnerability to loosening, particularly in the area of bone gaps, with findings consistent between biomechanical testing and FEA. This study offers valuable information on the surgical implications and biomechanical considerations of plate fixation for en bloc distal radius resection with ulnar reconstruction.

Although railway axles are a crucial part of railway vehicles, they are susceptible to long-term failure because of repeated loads. The aim of this research is to investigate the stress intensity factor (SIF) of a surface elliptical crack on a high-speed railway axle under various operating conditions. The study employs numerical analysis to explore the impact of press-fitting, rotary bending, stable and adverse running conditions on the SIF solutions. The main findings demonstrate that adverse running conditions, such as the press-fitting force, asymmetric vehicle weight, lateral force and wheel-rail contact force, can significantly increase the SIF values and result in axle failure. The press-fitting effect and rotary bending also have a significant impact on the SIF values, highlighting their importance in the railway axle design and analysis. The outcome of this research emphasizes the significance of accurately estimating SIF values to ensure the safe and reliable performance of railway axles in adverse operating conditions.