Vinayak Ranjan

Human gait data becomes very helpful in the prediction and correction of movement control while walking. In many areas like medical practices, Physical fitness training programs, rehabilitation techniques and prosthesis performance, gait study has its significant scientific relevance and applications. This study aims to predict the performance of Jaipur knee joint in terms of gait symmetry with transfemoral Indian amputees. First time we tried to calculate gait symmetry of widely used Jaipur knee joint with Indian population. This aspect has not been focused so far with Indian amputees. 11 unilateral transfemoral amputees (9 men and 2 women; average age 45 years, range 31-58 years) participated in the study. Subjects were using prosthesis with Jaipur knee for long time (mean: 16 yrs; range: 5-27 yrs). To investigate the gait function with 6 Vicon cameras 3D motion analysis system (Kinematrix system) participants were asked to walk with their comfortable speed. Gait symmetry, might be the basis of recommendation of knee joint. Kinematics parameter is predicted quantitavely gait symmetry with Jaipur knee joint. This research will result in significant prevention of degenerated musculoskeletal effects in future generally seen in unilateral transfemoral amputees.

Three-point bending test is conducted by help of Finite Element Method to find out mechanical properties of Inconel 718 coating on stainless steel. For doing this ANSYS package are employed to visualise exact situation of bending test so that can find out stress field developed during the test. A 3D modelling of coating and substrate material is used. Load versus displacement relationships is compared with reference results. It is noticed that yield stress of substrate material is higher than the tensile stress of substrate and coating. Due to this reason there is initiation of crack at coating-substrate interface and it is propagated which leads to failure with applied load.

In this paper, comparison of natural undamped frequencies of isotropic plates are investigated by using the dynamics stiffness element for isotropic plates. The DS Matrix for isotropic has been formulated by the application of classical plate theory. The generalized DS matrix has to solve by using Wittrick-Williams algorithm. Results of different aspect ratio have been validated from the existing literature.

Model has been for proposed for estimating the wear rate in dual phase (DP) steel for the run-in and the steady state of wear based on estimated load sharing between the constituent phases i.e., ferrite and martensite. The model has been checked by conducting pin-on-disc sliding wear tests on DP steel, Armco (pure) iron and fully martensitic steel (FMS) samples at normal loads of 14.7, 19.6, 24.5, 29.4 and 34.3 N and at a fixed sliding velocity of 1.15 m/s. Armco iron and FMS simulate the constituent phases in DP steel i.e., ferrite and martensite. The wear rates predicted by the proposed model have been found to match well with the experimentally observed wear rates in the regime of lower loads for the steels containing relatively lower volume fraction of martensite. However, wear rates have increasingly larger difference at higher loads. The difference in the estimated and the observed wear rates has been attributed to the flow of the softer phase of ferrite over the hard martensite islands and its relatively higher rate of wear.

The Shear Thickening Fluid (STF) is a non- Newtonian fluid which comes under dilatant material, STF undergoes phase transition from a low to high viscosity when shear stress is applied on it. In this paper modelling and simulation tools are used to study the STF fluid interaction when subjected to applied shear stress. The Eulerian description used for the fluid flow and the model considered the Lagrangian description of the rigid particles. The numerical analysis inspects important guideline such as acceleration of the flow, particle dispersion and the base of Non-Newtonian fluid. The fluid particles interrelation of STF showed that the shape, arrangement, volume concentration, and size of the particles had a vital effect on the behavior of STF. By adding sand particles in non-Newtonian fluids and applying high shear strain rates showed improvement in the shear thickening effects.

In this study, a comparison of sound radiation characteristic of a clamped free annular circular plate with different parabolically varying thickness with different taper ratios 0.25, 0.50 and 0.75 with different excitation locations are analyzed by keeping the mass of the plate constant. Rayleigh integral is applied to determine the acoustic behavior of the plate. The same problem is also solved by FEM to draw the comparison. It is observed that excitation locations and modes have a significant effect on sound power level in comparison to stiffness variation due to different taper ratios. Further, the variation of peak sound power level is investigated with different taper ratio with different excitation locations. Finally, the design options for peak sound power are suggested for different excitation locations with different taper ratios.

To get better understanding of vortex shedding mechanism, we conducted numerical simulation on NACA 4418 hydrofoil at an angle of attack of 12° for 2D incompressible flow. The numerical method consists of transient, finite volume method using Transient SST turbulent model to capture the turbulent wake flows. At high Reynolds number the occurrence of 2D structures of shed vortices and the modulation of vortex-induced frequency are investigated. The lift, pressure and skin friction coefficients of hydrofoil were studied.