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This paper presents an analysis of stress developed in flex-gear (FG) cup with conventional strain wave generating (SWG) cam and split-cam SWG in strain wave gear/harmonic drive (HD), using initial load distribution by tooth pairs as a boundary condition in finite element method (FEM). The initial load distribution by tooth pairs is achieved with the assembly of ring gear (RG) and deformed FG before the application of any external load. A closed-form solution to the analytical method describes the exact initial load distribution by tooth pairs in the presence of secondary contacts. However, with spit-cam SWG the phenomenon of secondary contact is completely eradicated. Therefore, the load is distributed by contacting tooth pairs that lie only in the line of action and the tooth pair that lies along the major axis of split-cam SWG experiences maximum load compared to conventional SWG. The strain developed in FG cup based on the load distribution with both SWG cams obtained from FEM is verified with the experiment. The comparison shows a rise of 44 microns in circumferential strain around the major axis of deformed FG, when RG is assembled. This testifies the presence of initial load, which is distributed among all interfering tooth pairs before applying external load. [ABSTRACT FROM AUTHOR]

Transient stress and deformation analysis of a functionally graded rotating cylinder made of Al-Sic with short length under thermal and mechanical loads is studied in this paper. It is assumed that the cylinder is located on a friction bed and is subjected to an external torque. The material property is assumed to be variable along the radial direction based on volume fraction distribution. Thermal conductivity equation with time parameter is solved to obtain temperature distribution by Finite Difference Method. First-order shear deformation theory is used to derive kinematic relations. The governing equations are derived using minimum total potential energy and Euler relations. These governing equations are solved using the method of Eigenvalue and Eigenvector. The physical and loading boundary conditions are applied to obtain unknown coefficients. As the main result of this paper, it is concluded that the radial displacement is uniform at the middle of a cylindrical shell and is decreased to zero with an increase of axial coordinate. [ABSTRACT FROM AUTHOR]

Modern advancements and emerging trends in automobile technology have shifted the primary focus of the OEMs to make vehicles lighter, faster, and reliable. Weight has always been a major concern in commercial medium/heavy-duty vehicles. The leaf springs account for 20% of the sprung weight of the vehicle thereby making the suspension system one of the heavy components of an automobile. This paper focuses on analysing the potential of aluminium alloy as a candidate material in leaf spring so as to make the suspension system lighter and more reliable. Aluminium alloy is one of the appropriate materials to proceed with because of its lightweight, strength, and non-significant deformation during load cycles. Three-dimensional CAD model of standard leaf spring was created in DS CATIA V5R19 software and computational analysis were carried out in ANSYS Workbench 18.1 by defining material as plain carbon steel (structural steel) and Aluminium alloy for comparative study. The results of the analysis that the reduction in weight of the leaf spring using aluminium alloy was approximately 64.71% along with a significant reduction in equivalent stress induced at different loading condition with a maximum reduction of 45.30% equivalent stress at the fully loaded dynamic condition. [ABSTRACT FROM AUTHOR]

This paper presents a new investigation of the recirculation channel combined with bleeding channels, where the recirculation airflow recirculates air from downstream high-pressure region to an upstream through a recirculation channel located on shroud surface in rotor domain and the bleeding airflow through 36 bleeding channels sited on the recirculation channels ejects airflow to the by-pass channel in a single-stage transonic axial compressor used in turbofan engine. The object of this investigation is to reduce the vortex flow in the tip leakage region by finding the effects of recirculation and bleeding channels design on aeromechanic performance of a single-stage axial compressor, NASA Stage 37. A parametric study of the recirculation and bleeding channels were performed using various geometric parameters related to the locations and shapes of the recirculation and bleeding channels to find the effects of recirculation and bleeding channels design on aeromechanic performance, such as pressure ratio, efficiency, stall margin, blade tip deformation and Von-Mises stress. The numerical results showed an increase in aerodynamic performance and decrease in blade tip deformation with recirculation-bleeding channels, compared to the smooth casing. [ABSTRACT FROM AUTHOR]

This paper presents sensitivity analysis of stress behaviour in the elements of bicycle frame having diamond structure with respect to design parameters. In order to achieve this goal stress on each element of the diamond frame have been derived in the form of analytical expression in terms of design parameters by imposing static equilibrium condition on 2D representation of the frame. Stresses on all the elements and reactionary forces on the frame are linear combination of two external loads on the frame with coefficients being trigonometric expressions. Stresses on all elements and reactionary forces have a common term which appear as denominator and is termed as Inter-element Interaction Common Factor (IICF). Analytical expressions for stresses on elements have the potential to provide insights into the set of values of design parameters for optimization of bicycle frame with respect to various criteria. Such insights, in addition to being valuable for designers using computer aided engineering softwares like ANSYS, are also helpful for comparative analysis among various design criteria. [ABSTRACT FROM AUTHOR]

This paper presents the parametric design optimisation of the bellows multi-response convolution stresses using multiple attribute decision making (MADM) technique. Grey Relational Analysis (GRA) in conjunction with Principal Components Analysis (PCA) has been employed to find a single response grade (PCA-GRG). Experimental stress analysis was carried out using L25 Taguchi orthogonal array (OA) by considering the design parameters, namely, ply thickness (tp), convolution height (H),convolution pitch (q), and bellows pitch diameter (dp). Analysis of variance (ANOVA) has been implemented to identify the most influenced significant design parameters and optimal design level settings using PCA-GRG. Confirmation test was conducted which proves the improvement in GRG by 0.042 (25.30%) over the initial setting of the factors. Further, multiple regression mathematical models were developed to find the best alternate optimal solutions and verified it by comparing with experimental GRG and Taguchi predictions. Alternate optimal solution signifies the improvement in PCA-GRG over the initial parameter setting from 13.04% to 32.6%, which directs the extensive reduction in the stresses. This verification proves the potential of the integrated PCA-GRG approach for the multi-response parametric optimisation of the convolution stresses. [ABSTRACT FROM AUTHOR]

The objective of this paper is to investigate the mechanical behaviour of the inner sleeve for a new type of hydraulic safety coupling. Based on the theory of space axis symmetric and hollow cylinder problem in elasticity, a comprehensive formulation of a mathematical model is presented. The model takes both the non-bending theory and the bending theory into account. And then the effects of three kinds of boundary conditions on deformation and stress fields in the middle section of the inner sleeve are analysed. The experimental data for a particular model using the screw regulation way are compared with the calculated data. It is shown that any form of constraints on either end of the inner sleeve can ultimately lead to the increase of deformation. When one end is fixed and the other end is free, the maximum deformation occurs at the adjacent zone of the middle cross section of the inner sleeve. The maximum stress under the boundary condition of both ends is simply supported is larger than that under the other two boundary conditions. The model developed in this research will potentially form the framework for a complete model in further research. [ABSTRACT FROM AUTHOR]

This paper carries out the experimental and numerical investigations on the root stress of a light-load spur gear drive. An improved gear test rig is developed to enable the dynamic root stress of a light-load spur gear drive to be wirelessly measured, and the signals of root strain, rotational speeds and torques of input/output gear shafts are sent or received wirelessly. After the random electrical noise is eliminated by multi-point average method, the key parameters of dynamic contact analysis on the root stress (rotational speeds and torque) are obtained, and the root strain signal is converted into root stress. Based on the curve of the measured root stress, the impact of meshing teeth and the alternative variation in the single and double pair gear meshing can be attained quantitatively. The geometric model of gear is developed by the generative machining principle and the coordinate transformation method. Then, the dynamic contact analysis is performed by the display centre difference method to obtain the maximum tensile stress of the tooth root, which is compared with the results in literature as well as the wireless measurement data. It shows that the wireless measurement approach and the developed method of dynamic contact analysis are effective and efficient. [ABSTRACT FROM PUBLISHER]

Contour integral method is the conventional approach in order to characterise main crack parameters in fracture studies. This method is used in verity fields in fractures mechanics because of its capability in linear and non-linear fracture mechanics. Whereas, requirements such as mesh singularity in crack tip and refined layers of elements in surrounding contours, which increase computing time and make it prolix for large components. The main aim of this paper is to develop an extended finite element method-linear elastic fracture mechanics (XFEM-LEFM) model to impart XFEM advantages in survey of fracture mechanics of planetary gear sets. At first main crack parameters of root crack of the planet gear have been obtained and compared with conventional method, and after that crack growth path is predicted, and finally effect of rim thickness is investigated and compared with other researches to illustrate the efficiency of the developed model. For this purpose, Python script code is generated to automatically calculate the stress intensity factors of root crack and after that simulate the crack growth path until final fracture. [ABSTRACT FROM AUTHOR]