No abstract

Finite element analysis is extensively used in the design of rubber products. Rubber products can suffer from large amounts of distortion under working conditions as they are nonlinearly elastic, isotropic, and incompressible materials. Working conditions can vary over a large distortion range, and relate directly to different distortion modes. Hyperelastic material models can describe the observed material behaviour. The goal of this investigation was to understand the stress and relegation fields around the tips of cracks in nearly incompressible, isotropic, hyperelastic accouterments, to directly reveal the uniaxial stress–strain relationship of hyperelastic soft accouterments. Numerical and factual trials showed that measurements of the stress–strain relationship could duly estimate values of nonlinear strain and stress for the neo-Hookean, Yeoh, and Arruda–Boyce hyperelastic material models. Numerical models were constructed using the finite element method. It was found that results concerning strains of 0–20% yielded curvatures that were nearly identical for both the neo-Hookean, and Arruda–Boyce models. We could also see that from the beginning of the test (0–5% strain), the curves produced from our experimental results, alongside those of the neo-Hookean and Arruda–Boyce models were identical. However, the experiment’s curves, alongside those of the Yeoh model, converged at a certain point (30% strain for Pieces No. 1 and 2, and 32% for Piece No. 3). The results showed that these finite element simulations were qualitatively in agreement with the actual experiments. We could also see that the Yeoh models performed better than the neo-Hookean model, and that the neo-Hookean model performed better than the Arruda–Boyce model.

No abstract

No abstract

State of the art of hydrodynamic journal bearing lubrication is realized by a significant oversupply with lubricant, causing energy losses due to fluid film friction in the unloaded areas of the bearing. Reducing the lubricant flow however may lead to overheating or collapse of the load carrying fluid film, both resulting in a complete failure of the journal bearing. A new approach to safely reduce the lubricant flow is presented in this paper, by using a broadband piezoelectric acoustic emission sensor to detect ultrasonic structure-borne noise, usually caused by metal-to-metal contact at boundary conditions. The method of structure-borne noise analysis has proven to be suitable for detecting the occurrence of solid friction [1–4]. By combining structure-borne noise analysis with a closed loop control of a proportional flow control valve a condition dependent lubricant flow can be set. Thus lubricant friction in the bearing is reduced and additionally electrical energy in the peripheral devices, such as pumps can be saved.