Theses and Dissertations

The stamping process, of which the punching process is a major division, is one of the most important metal parts production methods in industry. Punching dies are the heart of the punching process. Die performance, as measured by the number of strokes between sharpenings and/or repairs, determines the important per part costs of die depletion and maintenance. Existing quantitative studies are principally on tool wear and punchability.

The stress intensity factors have been shown to control the rate of propagation of a crack when material is subjected to cyclic loading. This experimental study was undertaken to verify the existence of a critical stress intensity factor in bending which controls crack extension.

This hypothesis: a direct correlation exists between methods changes and related productivity changes in non machine-controlled work situations, appeared to be at the root of many problems in applied work measurement. Therefore, the author decided to conduct an objective, quantitative analysis of its validity.

The fundamental relationships among the design parameters of an information system and the utility of the information that a system produces are analyzed in an effort to develop a methodology for measuring the utility of information. The utility of the information is defined as a measure of the effectiveness with which the information can be employed to attain the objectives of the using organization.

The purpose of this research was to further the investigation into GERT output distributions. From the family of GERT networks containing only Exclusive-Or nodes, a generally applicable network form was chosen for simulation. A generalized computer program was written to simulate any specific network of this form.

The aim of this thesis is to present a solution of the problem of thermal stresses in a finite hollow cylinder due to a sudden change in temperature on the inner boundaries.

The solutions to the problems of production forecasting, scheduling, and in-process inventory control for high volume multi-product manufacturing lines are not readily available in current industrial literature. This study proposes simulation as a general approach to solving these problems and proceeds to develop a simulator which is applied to just such a high volume line.

The building industry is perhaps the most fragmented large industrial complex in the country today. Consumers are expressing needs for faster delivery for more functional and sophisticated space at more reasonalble prices. At the same time, the industry in itself is faced with growing internal problems which are making it increasingly more difficult to perform even as well as in the past. This study investigates the area of utility sub-systems in the building industry.

Utilizing CRAFT an optimum plant layout with regard to all products manufactured can be realized. In addition, two manufacturing policies; related to production and inventory control, will be investigated with respect to the effect of said policies on plant layout.

Computational efficiencies of the primal-dual algorithm and the uv-method in solving transportation problems are compared in this thesis. A computer program was written in Fortran IV and run on the CDC 6400 system; it generated random problems with integer constants ranging in the size from 5X10 to 30 X 50, and solved them by both methods.

The order of the stress singularity at its vertex of a wedge of two bonded elastic media under longitudinal shear is solved by use of the Williams method. The similar problem of an elastic wedge bonded to a rigid foundation is also solved using the same method. Next, the problem of a cylindrical elastic media whose boundary is a polygon bonded to a rigid foundation and subjected to various types of longitudinal shear loads on its boundary is considered. A number of examples are worked out and expressions for contact stresses along the bonds are given.

A testing machine has been built for the cyclic bending of thin cantilevered plates for crack propagation studies. The report includes sections covering design considerations of the testing machine, preparation of specimens, observations during testing, and some preliminary test results.

This is a result of an initial investigation to simplify feedback controllers for stochastic processes. The investigation concerns itself with incrimental control as opposed to proportional control.

The problem considered is that of determining the 2-dimensional thermal stresses in a thick-walled finite hollow circular cylinder subjected to an axisymmetric temperature distribution.

This paper concerns itself with quantification of the intangible factors in Product Design Decisions where there is one very big supplier with one very big customer and a unique product. The product design is represented as a state diagram, or curve, with Time as one axis and Product or Material State as the other. Industry affects the product design curve with various levels of decisions. This paper describes four of these levels and investigates a case in which three levels are involved.

A simulation program is presented that develops a risk profile of the intended investment. The risk profile is essentially a return on investment probability analysis developed from the estimated distributions of costs, service life and savings of the intended investment in a computer based, on-line system.

An investigation of the feasibility of applying linear programming to assembly line balancing problems is presented. Salveson and Bowman developed the mathematical models.

The problem of an infinite medium containing a crack near an arbitrarily located circular elastic inclusion and subjected to a uniform longitudinal shear stress at infinity is considered. By embedding a layer of body forces at the interface, the problem for the nonhomogeneous medium is reduced to two problems for homogeneous materials.

The subject considered in this paper is the temporal relationship of data flow through an information system and how this flow may be described by a mathematical model.

A production inventory control model is developed using servo-mechanism principles. This model developed is the result of modifying an existing model which assumes that scheduled production always equal actual production. The modified model is designed to reduce production level fluctuations while maintaining a minimum amount of inventory on hand.

This study was conducted for the purpose of evaluating various safety stock policies in a dynamic, multi-echelon inventory system. The study environment is set in a four level multi-echelon production system. Demands on the system are forecast over a twenty period planning horizon and are treated in the model as deterministic. Safety stock is required to protect against lead time variation which is assumed to be distributed in a Poisson manner. All costs are assumed known with the exception of stockout cost.