Showing papers in "International Journal of Design Engineering in 2023"
TL;DR: In this article , the authors used the R10 method to discretise the amount of oil to explore the evolution of lubricating oil distribution in the support bearing of a helicopter tail drive system under lubrication loss conditions based on the idea of computational fluid dynamics.
Abstract: Double row tapered roller bearings have excellent load-carrying behaviour and are widely used in helicopter tail drive systems. If the helicopter is attacked, the bearings are working at loss of lubrication condition. This study using the R10 method to discretise the amount of oil to explore the evolution of lubricating oil distribution in the support bearing of a helicopter tail drive system under lubrication loss conditions based on the idea of computational fluid dynamics (CFD) and considers the revolution and rotation speed of bearings. The lubricant distribution on the large rollers, small rollers, and inner ring walls on both asymmetrical sides was analysed, and the quantity of oil and lubricant inside the bearing were estimated. It is found that the recommended speed range of bearing is 4,000-5,000 r/min, and the value for the number of rollers in the bearing was determined to be no more than 22 large rollers and no more than 25 small rollers.
TL;DR: In this article , a structural steel spring plate using FEM and design of experiments (DoE) was used for DoE, and FEM was used to model and solve various design points.
Abstract: The current study aims at design exploration of a structural steel spring plate using FEM and design of experiments (DoE). Box-Behnken design (BBD) was used for DoE, and FEM was used to model and solve various design points. First, structural analyses of the spring plate were performed to determine the maximum deformation and von-Mises stress in the model. The study considered bend radius (P1), hole spacing (P6), and internal and external thicknesses (P11, P12) as input parameters. Twenty-five BBD-based numerical experiments were run in ANSYS WB. Regression analysis yielded accurate output parameter regression models based on input parameters. ANOVA was used to determine the importance of each input parameter on the output parameters. Response surface methodology (RSM) was used to determine the change in response variable vs. input parameters. The goodness-of-fit analysis showed good agreement between RSM-predicted and FEM-determined output parameters.
TL;DR: In this paper , the dimensional accuracy of the wax replicas generated by room temperature vulcanisation (RTV) silicon rubber molding for stepped bar pattern to be used in investment casting was investigated.
Abstract: This paper presents the dimensional accuracy of the wax replicas generated by room temperature vulcanisation (RTV) silicon rubber moulding for stepped bar pattern to be used in investment casting. The main purpose of this research work is to investigate the effect of process parameters on dimensional accuracy and test its practical implication in RTV moulding technique. To study the influence of process factors, a 3-factor 4-level (L16) orthogonal array experiment is designed as per Taguchi method and the result is reported. A case study for research of dimensional accuracy of wax patterns created by RTV silicone rubber mould had not been attempted as earlier for stepped bars. As this appends an additional stage in the tooling process, it is evident to estimate and predict the dimensional deviation from RP model and its wax replica. Experimental results show the dimensional accuracy in RTV technique is accurately the same as in traditional moulding. It was realised that RTV tooling technique can be used efficiently to produce wax patterns at optimum condition in investment casting.
TL;DR: In this article , the influence of steel fibres (SFs) on the sorptivity of RC members exposed to a corrosive environment was investigated. But the authors focused on the effect of SFs in concrete on its rate of water absorption.
Abstract: The present paper describes the influence of steel fibres (SFs) on the sorptivity of RC members exposed to a corrosive environment. The concrete because of its inherent microstructure has a tendency to allow the ingress of moisture and other harmful gases into it, which triggers the corrosion of embedded rebars. The presence of other cracks therein further augments the rate of absorption that lead to their accelerated deterioration. With this background and the well-known crack-arresting potential of the SFs, an investigation was carried out on control, pre-loaded, and pre-corroded and loaded RC specimens to establish the effect of SFs in concrete on its rate of water absorption. In order to quantify this effect, sorptivity test was conducted on the cores extracted from the loaded un-corroded and corroded RC beams. It was found that inclusion of fibres alleviates the surface water absorption tendency of the concrete which enhances the durability.