Mechanical Engineering

Chemical vapour deposition (CVD) is a widely used method for depositing thin films of a large variety of advanced materials. Applications of CVD range from the fabrication of microelectronic devices to the deposition of protective coatings but also optoelectronic films, decorative coatings.

The problem of robot selection plays an important key role concern to various fields of different applications since three decades. This problem has become more difficult in recent years due to increasing complexity of applications of the environment, features and specifications, and facilities offered by various manufactures. The primary objective of this paper is to select the suitable type of robot based on various factors such as type of application, payload, working environment, accuracy, lifespan, weight, purchasing cost etc. The selection procedure is developed for selection of particular type of robot based evaluating the various alternative selection factors using AHP technique and systems of equations of the matrices i.e. Eigen values and Eigen vectors. The ranking evolution will provide a good guidance for the robot selection to the end user. The concept of this work is an attempt has been made to create exhaustive database for identifying maximum possible number of attributes.

The present paper addresses the concept of CSF in the development of new products. More specifically, the aim of this research is to study how performance is perceived and measured within the companies, and how this can be improved. The target respondents are Indian SMEs. 18 critical factors are identified and with the help of semi structured questionnaire the data is collected. The collected data is being analyzed in SPSS software. The results show that the identified factors are related to success of new product in the Indian SMEs.

A numerical model has been formulated to simulate the capillary tube in split air conditioners of 1 and 2 TR capacities under high outdoor air temperatures. The outdoor air temperature was varied from 35 to 55°C with 5 °C increments. Three environment friendly refrigerants were used as alternatives to R22. They are R290, R407C and R410A. Finite difference method has been adopted in conjunction with EES software. This model is capable of predicting pressure, temperature, quality, velocity and viscosity distributions through the capillary tube for all refrigerants. The geometrical parameters and input conditions to the capillary tube model are extracted from experimental data. These include inner diameter, mass flow rate, surface roughness, temperature and pressure of the subcooled liquid refrigerant.The results show that the capillary choking length increases with increasing outdoor air temperature. Results of the simulation show that R290 needs more capillary length than the other refrigerants investigated, whereas R410A needs less capillary tube length.

In this study, the deformation behavior of 93Tungsten alloy under the hydrostatic extrusion has been investigated. The hydrostatic extrusion process of 93 Tungsten alloy has been analyzed by means of finite element method (FEM). The numerical results were highly corresponded to the experimental ones. Also the effect of die angle on the extrusion pressure and applied damages to the 93 Tungsten alloy during the process of hydrostatic extrusion has been investigated according to the Cockcroft & Latham damage criterion. As was deduced from results, when the die angle has been considered as 30°, the applied damages to the material during the process were negligible in comparison with higher values of die angle.

Topology is a branch of geometry concerned with the properties remains unchanged when the figure is deformed. The significance of topology is which will help to develop light weight components which are used in manufacturing of two wheeler carts, etc., the result is we get better automobile fuel efficiency. This in turn results to energy conservation and global environmental preservation. In industries several attempts are made to produce lightweight designs. In order to manufacture light weight component our first step is to decrease the weight of the wheel rim. The wheel is designed using CATIA and Imported CATIA 3D Model into Altair Hyper Mesh V13 for doing Pre-processing and ALTAIR Optistruct Software for doing optimization and structural analysis of the wheel rim. The aim of this work is to develop an optimization procedure in order to reduce the weight of rim component. The focus of this project has been the weight reduction of an aluminium wheel by means of a topology analysis.

Groundwater resources are essential to maintain a stable water supply to growing cities for the efficient farming region and for domestic purpose. Due to simplicity of the techniques, the Vertical Electrical Sounding (VES) has proved very popular with groundwater prospecting and engineering investigations. The main objective of the investigation is to delineate the subsurface lithology and to assess the groundwater resources of the study area. It also aims to focus on the identification of fracture zone and its thickness by using VES method. The life of a button bit in bore well drilling depends mainly on hardness of rock. As the hardness varies at different locations, the reliability of the button bit also varies accordingly. In order to arrive at the reliability, the life of the button bit in terms of depth of drilling has to be obtained. This can be converted in terms of time from the known velocity of drilling. It is proposed to arrive at the drill bit reliability from the obtained failure rate.

Analysis of Reversed Hazard Rate (RHR) can provide insights in making it suitable for industrial applications. From the published literature it is learnt that Nature of reversed Hazard rate for standard continuous distributions is a decreasing function. Obviously this makes RHR suitable in the field of maintenance engineering to address hidden failures in a given system. One of its most useful applications lies in the assessment of waiting time of hidden failures. RHR is closely related to another important concept known as the mean waiting time. This concept is useful in casualty insurance, reliability, and medicine including forensic science to predict times of occurrences of events. For instance, the incubation times of diseases, are difficult to measure because the infection time is unobserved in general. Mean waiting time will offer its great help in such situations, which are analyzed and incorporated appropriately in this paper.

This paper reports the effects of sintering schedule to the mechanical properties and microstructure of warm formed powder compacts. Iron powder ASC 100.29 was used as main powder constituent whereas zinc stearate was used as lubricant. The premixed powder mass was compacted at 180ºC by applying 130 kN axial loading and sintered in an inert gas fired sintering furnace at different sintering schedule. The sintered samples were characterized to evaluate their mechanical properties and microstructures. The effect of sintering schedule was studied in terms of mechanical properties, focusing in particular on the relative density, flexural strength and hardness. The microstructure analysis was performed to determine the pore shape, size and distribution. The results revealed that the mechanical properties and microstructures of sintered products were affected by the sintering temperature, holding time as well as the heating/cooling rate.

The main purpose of this study is to analysis the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase. The thermal-structural analysis is then used coupling to determine the deformation and the Von Mises stress established in the disc, the contact pressure distribution in pads. The results are satisfactory when compared with those of the specialized literature.