Mechanical Engineering Commons^™

Tools For The Design Of Flexible Manufacturind Systems, Prashant A. Patel

Theses

Flexibility in manufacturing systems can broaden the horizons for a company. But the means for achieving it are far more critical. This trend is created by the increase in competitiveness, growth of technology along with demand variations, more customization, and short product life cycles. But "Flexible Manufacturing Systems" to most of the manufacturers sounds like a synonym for automation.

A real Flexible Manufacturing System is designed when every unit of the company is synchronized in such a way to respond in a harmony to any changes that come against it. Fine-tuning of each and every part of the company is …

Object Oriented 3d Dynamic Simulation Of Flow Of Material Through Hopper, Krishnendu Roy

Theses

Development of object oriented 3D dynamic simulation of the particle is considered. This code is based on the soft sphere model dealing with both normal force , tangential force and the friction. The development of such a model and the code is motivated by the need to understand the flow patterns of granular material. The prime effort while developing this code was focused on the data encapsulation and secured access to all the attributes of all physical parameters of the bulk solid, which might be endangered by the random access of the interface of the software. A dynamically bound array …

Design Of An Effective And Timely Product Development Process For Medical Devices, Jean Benoit Almonor

Theses

Effective product development process is one of the most critical issues facing medical devices manufacturing today. There is a need to search for ways to improve or solve the cross organization and company boundaries to enhance the faster release of new medical products to the market. This thesis presents an integrated set of perspectives on the process of new product development of medical devices with dual goals of achieving marketing speed and meet customer satisfaction.

The Attribute Driven Specifications approach described in this thesis, is one of the most valuable tools in the approach to effective product development in medical …

Demanufacturing Metrics For Industrial Fasteners And Disassembly Process, Narendra P. Raj

Theses

As the society progresses towards ecological maturity, the issue of reducing the environmental burden imposed by used products becomes increasingly important Environmental issues are becoming increasingly relevant for product designers and manufacturers. Public awareness of the value and fragility of an intact ecology is constantly growing, and the traditional assumption that the cost of ecological burdens to be shared by a society, as a whole is no longer accepted. Environmental protection legislation requiring manufacturers to "take back" and recycle used products will be a commonplace throughout Europe and the U.S. in the near future.

Demanufacturing involves separating and disassembling a …

Dynamic Friction Measurement, Modeling, And Compensation For Precise Motion Control, Simon Cohn

Theses

In this thesis, measurements of dynamic friction in a hydrodynamic journal bearing were performed for varying sinusoidal velocity excitations, loads, and lubricants. The results indicate that the friction data displays a negative slope in the mixed region of friction vs. velocity (f-v) curves, and also shows that the dynamic friction is not just a function of current velocity, but also a function of velocity history (hysteresis). These results are in agreement with previous experimental investigations by other investigators in lubricated friction.

Secondly, a dynamic friction model is fully explored and partially extended to provide quantitative agreement to measured friction values. …

Optimal Synthesis Of A Planar Four-Bar Function Generator Based On Imderect Measure Of Structural Error, Robert Ellis

Theses

A novel technique for optimal synthesis of a planar four-bar function generator is presented. An indirect measure of structural error is used to formulate an objective function which, along with its derivatives, is straightforward to evaluate and results in an elegant and robust algorithm. Lagrange multipliers are used to incorporate the loop closure constraint into the objective function.

In this thesis, the formulation of the objective function and the minimization algorithm are described, examples are presented, and the virtues and shortcomings of the algorithm are discussed.

Parameter Optimization For Curl Distortion In Building Parts Using 3-D Laser Stereolithography, Laurel A. Hanesian

Theses

The curl distortions in rapid prototyping using 3-D laser stereo lithography occur as the top layers shrink after being drawn and attaching to the bottom layers. The amount of curl is dependent upon the how much shrinkage the layer has finished prior to adhesion. It is also dependent on how deep the cure of the top layer amounts to as it adheres into the bottom layer. This thesis investigated the effect of build parameters on the distortions associated with the diagnostic 'Letter-H' shaped test part. The same parameters were also considered in a time optimization study, using calculated, predicted results …

Kinematic Analysis Of A Swash-Plate Mechanism Using Transformation Matrices, David Edgar Evans

Theses

The swash-plate mechanism is used to transfer rotational motion into translational motion and vice versa. Using transformation matrices to describe each joint, the displacements of the swash-plate mechanism were analyzed. The general transformation matrix model for the plane joint, not previously developed using transformation matrices, was presented. The solution was tested using a computer program. Examples of three different swash-plate angles; 10, 45, and 25' were considered. The solution was found to agree with previous solutions while offering a more complete description of the mechanism. Future work in this area could include a complete static, velocity, and/or dynamic analysis of …

Virtual Reality Modelling Of A Cnc Machine, Damian O'Sullivan

Theses

The increasing importance of training and upgrading skills has led to the use of new interactive technologies in the development of more effective training tools. Previous techniques for training Computer Numerical Control (CNC) machine operators, while excellent for their time, varied from brief inexpensive tutorials to expensive on the job training. A CNC machine uses a computer to perform the functions of the machine using a part program stored in the memory of the computer. This thesis describes a Virtual Reality (VR) model of a CNC milling machine, implemented within a VR environment representing a CNC workshop. Its development and …

An Investigation Using The Finite Element Method Into Bowing & Lean Of The 3rd Stage Turbine Blade Of The Pratt & Whitney Jt8d Gas Turbine Engine, Kevin O'Donoghue

Theses

Following a recent series of failures of overhauled third stage turbine blades in the JT8D- 15A gas turbine engine, new inspection criteria have been introduced by the engine manufacturer Pratt & Whitney. One such inspection checks for airfoil bowing and lean. A blade will bow or lean towards the suction face of the airfoil as a result of creep during engine operation. Third stage turbine blades from the JT8D low pressure turbine have been observed with as much as two millimetres of deflection measured at mid-span. In a geometrically correct T3 blade, the tensile centrifugal load due to engine rotation …

Development Of A Geothermal Heat Pump Test Facility, Chris Collins

Theses

Current environmental concerns have led to large scale research and development in the area of alternative energy supplies. The alternative energy system of interest in this study is the heat pump. Heat pumps extract heat from a variety of sources such as air, water and the earth, upgrade and transmit it to the required location. The aim of this thesis is to develop mathematical and experimental models to evaluate the performance of a heat pump which uses the earth as its thermal source. These models will then form the basis of design aids for installers sizing closed loop collection systems …