published_or_final_version / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

In this research, an approach is developed to automate the design for sheet metal parts that are not only novel and manufacturable but also satisfies multiple objective functions such as material cost. Unlike commercial software tools such as Pro/SHEETMETAL which aids the user in finalizing and determining the sequence of manufacturing operations for a specified component, our approach starts with spatial constraints in order to create the component geometries and helps the designer design. While there is an enormous set of parts that can feasibly be generated with sheet metal, it is difficult to define this space systematically. To solve this problem, we currently have 108 design rules that have been developed for five basic sheet metal operations: slitting, notching, shearing, punching and bending. The technique revealed here represents candidate solutions as a graph of nodes and arcs where each node is a rectangular patch of sheet metal, and modifications are progressively made to the sheet to maintain the parts manufacturability. They are presented in the form of Standard Tessellation Language files (.stl) that can be transferred into available modeling software for further analysis. The overall purpose of this research is to provide creative designs to the designer granting him/her a new perspective and to check all the solutions for manufacturability in the early stage of design process. The abovementioned automation approach uses a new topological optimization technique to solve graph based engineering design problems by decoupling parameters and topology changes. This technique namely Topological and Parametric Tune and Prune (TP²) is the first topology optimization method that has been developed specifically for domains representable by a graph grammar schema. The method is stochastic and incorporates distinct phases for modifying the topologies and modifying parameters stored within topologies. Thus far, with the problems that been tested, (TP²) had proven better than genetic algorithm in terms of the quality of solutions and time taken to acquire them. / text

In March 1983, the General Electric Company Drive Systems Operations Division introduced the Distributed Micro-Controller (DMC) to the automation industry. The processor is used for high speed digital control of a number of devices. One of the first applications of the DMC was control high speed motor positioning for metal industry plant automation. In many attempts to control high speed position regulation, the problems that prevented the use of digital controllers included high cost, slow processing time, or poor mathematical capabilities. Usually to obtain two of these constraints, the third constraint became inhibitive (i.e., if processing time and mathematical capabilities were acceptable, then the cost of the controller was to high to make the use of the control device desirable). By incorporating the co-processor capabilities of the Intel 8087, a new era of digital control was available. By using the mathematical capabilities of the 8087 in conjunction with the logical processing capabilities of the 8086, a device was available to perform the mathematical calculations desired within an acceptable price range. The use of the two processes as parallel processors (at times synchronous processors, and at other times asynchronous processors) decreased the position regulation execution time to the point that the device met all three requirements needed. The parallel programming techniques that made the DMC acceptable as a high speed position regulation device are discussed in this thesis. / Master of Science

Today's manufacturing environment is characterized by competition and continuous change in product and process requirements. The concept of "design for manufacturability" integrates product specifications with manufacturing capabilities by considering the design and manufacturing phases as an integrated system, evaluating the combined system during the design phase of a product , and adjusting the design for maximum efficiency and production economics. This research focuses on one aspect of design for manufacturability, that of process technology evaluation for a specified product design. The objective of the proposed system developed in this study is to evaluate technology alternatives for manufacturing a specified part design and to identify the best combination of product-process characteristics that would minimize production costs within the constraints set by the product's functional requirements and available processing technology. The research objectives are accomplished by developing a simulation based analysis system. The user inputs product specifications through structural screens. The system maintains data bases of work and tool materials, and machining operations. Based on user input, the system then extracts appropriate information from these data bases, and analyzes of the production system in terms of production economics, and other operational measures such as throughput times and work-in-process inventories. Sensitivity analysis may then be performed to explore tradeoffs in design and production parameters. The system is completely integrated, and a user with no prior experience of either simulation or data base technology can use the system effectively. / Graduation date: 1992