In-Mold Assembly of Multi-Functional Structures

Combining the recent advances in injection moldable polymer composites with the multi-material molding techniques enable fabrication of multi-functional structures to serve multiple functions (e.g., carry load, support motion, dissipate heat, store energy). Current in-mold assembly methods, however, cannot be simply scaled to create structures with miniature features, as the process conditions and the assembly failure modes change with the feature size. This dissertation identifies and addresses the issues associated with the in-mold assembly of multi-functional structures with miniature components. First, the functional capability of embedding actuators is developed. As a part of this effort, computational modeling methods are developed to assess the functionality of the structure with respect to the material properties, process parameters and the heat source. Using these models, the effective material thermal conductivity required to dissipate the heat generated by the embedded small scale actuator is identified. Also, the influence of the fiber orientation on the heat dissipation performance is characterized. Finally, models for integrated product and process design are presented to ensure the miniature actuator survivability during embedding process. The second functional capability developed as a part of this dissertation is the in-mold assembly of multi-material structures capable of motion and load transfer, such as mechanisms with compliant hinges. The necessary hinge and link design features are identified. The shapes and orientations of these features are analyzed with respect to their functionality, mutual dependencies, and the process cost. The parametric model of the interface design is developed. This model is used to minimize both the final assembly weight and the mold complexity as the process cost measure. Also, to minimize the manufacturing waste and the risk of assembly failure due to unbalanced mold filling, the design optimization of runner systems used in multi-cavity molds for in-mold assembly is developed. The complete optimization model is characterized and formulated. The best method to solve the runner optimization problem is identified. To demonstrate the applicability of the tools developed in this dissertation towards the miniaturization of robotic devices, a case study of a novel miniature air vehicle drive mechanism is presented

Production line: effect of different inspection station allocation under accepts reject inspection policy

Manufacturing system is one of the most important parts in any organization as it produces the output of the company which will generate the profit. It consists partly of the production line which plays the role as the centre of production to create the end product which could be half finished or the full product. It is a big problem for the company to determine which is the better arrangement and combination of the tools or machines available in this area of the organization as different combination will greatly impact the productivity of the production line together with the profit of the company. This research intend to analyze a new production line in a metal stamping company based on the complain from the company and try to explore the better layout or arrangement in the production line in reflect to the complained problem and constrain of the provided of accept the defect and repair inspection policy. The production line is first being analyzed in response to complain through computer simulation. After the problem had been identified, the researcher tried different alternatives in the attempt to seek for the better layout or arrangement in the production line. The effect of different inspection station allocation layout is then being evaluated in term of the production time. The research has resulted in the finding of the cause for the long production time in the factory which is the long inspection steps which consumed much of the production time. After a few alternatives have been explored in allocating the inspection station, it is obvious that the current approach of the production line is the better one. Even by reducing the number of inspection station, interesting enough, the production time does not seem to decrease but yet increased. This finding contradicts the normal thought of fewer stations means shorter time. This finding could be the founding basic in the future research regarding the allocation of the inspection station following certain provided policy. This is also very helpful in real life practice in company as to help them improve their production time. As for the time being, there is yet a research addressing this issue pertaining the given inspection policy

A review on equipment protection and system protection relay in power system

Power system equipment is configured and connected together with multiple voltage levels in existing electrical power system. There are varieties of electrical equipment obtainable in the power system predominantly from generation side up to the distribution side. Consequently, appropriate protections must be apt to prevent inessential disturbances that lead to voltage instability, voltage collapse and sooner a total blackout took place in the power system. The understanding of each component on the system protection is critical. This is due to any abnormal condition and failure can be analyzed and solved effectively due to the rapid changing and development on the power system network. Therefore, the enhancement of power quality can be achieved by sheltering the equipment with protection relay in power system. Moreover, the design of a systematic network is crucial for the system protection itself. Several types of protective equipment and protection techniques are taken into consideration in this paper. Hence, the existing accessible types and methods of system protection in the power system network are reviewed

A review on equipment protection and system protection relay in power system

Power system equipment is configured and connected together with multiple voltage levels in existing electrical power system. There are varieties of electrical equipment obtainable in the power system predominantly from generation side up to the distribution side. Consequently, appropriate protections must be apt to prevent inessential disturbances that lead to voltage instability, voltage collapse and sooner a total blackout took place in the power system. The understanding of each component on the system protection is critical. This is due to any abnormal condition and failure can be analyzed and solved effectively due to the rapid changing and development on the power system network. Therefore, the enhancement of power quality can be achieved by sheltering the equipment with protection relay in power system. Moreover, the design of a systematic network is crucial for the system protection itself. Several types of protective equipment and protection techniques are taken into consideration in this paper. Hence, the existing accessible types and methods of system protection in the power system network are reviewed

Delay driven multi-way circuit partitioning.

Wong Sze Hon.Thesis (M.Phil.)--Chinese University of Hong Kong, 2003.Includes bibliographical references (leaves 88-91).Abstracts in English and Chinese.Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Preliminaries --- p.1Chapter 1.2 --- Motivations --- p.1Chapter 1.3 --- Contributions --- p.3Chapter 1.4 --- Organization of the Thesis --- p.4Chapter 2 --- VLSI Physical Design Automation --- p.5Chapter 2.1 --- Preliminaries --- p.5Chapter 2.2 --- VLSI Design Cycle [1] --- p.6Chapter 2.2.1 --- System Specification --- p.6Chapter 2.2.2 --- Architectural Design --- p.6Chapter 2.2.3 --- Functional Design --- p.6Chapter 2.2.4 --- Logic Design --- p.8Chapter 2.2.5 --- Circuit Design --- p.8Chapter 2.2.6 --- Physical Design --- p.8Chapter 2.2.7 --- Fabrication --- p.8Chapter 2.2.8 --- Packaging and Testing --- p.9Chapter 2.3 --- Physical Design Cycle [1] --- p.9Chapter 2.3.1 --- Partitioning --- p.9Chapter 2.3.2 --- Floorplanning and Placement --- p.11Chapter 2.3.3 --- Routing --- p.11Chapter 2.3.4 --- Compaction --- p.12Chapter 2.3.5 --- Extraction and Verification --- p.12Chapter 2.4 --- Chapter Summary --- p.12Chapter 3 --- Recent Approaches on Circuit Partitioning --- p.14Chapter 3.1 --- Preliminaries --- p.14Chapter 3.2 --- Circuit Representation --- p.15Chapter 3.3 --- Delay Modelling --- p.16Chapter 3.4 --- Partitioning Objectives --- p.19Chapter 3.4.1 --- Interconnections between Partitions --- p.19Chapter 3.4.2 --- Delay Minimization --- p.19Chapter 3.4.3 --- Area and Number of Partitions --- p.20Chapter 3.5 --- Partitioning Algorithms --- p.20Chapter 3.5.1 --- Cut-size Driven Partitioning Algorithm --- p.21Chapter 3.5.2 --- Delay Driven Partitioning Algorithm --- p.32Chapter 3.5.3 --- Acyclic Circuit Partitioning Algorithm --- p.33Chapter 4 --- Clustering Based Acyclic Multi-way Partitioning --- p.38Chapter 4.1 --- Preliminaries --- p.38Chapter 4.2 --- Previous Works on Clustering Based Partitioning --- p.39Chapter 4.2.1 --- Multilevel Circuit Partitioning [2] --- p.40Chapter 4.2.2 --- Cluster-Oriented Iterative-Improvement Partitioner [3] --- p.42Chapter 4.2.3 --- Section Summary --- p.44Chapter 4.3 --- Problem Formulation --- p.45Chapter 4.4 --- Clustering Based Acyclic Multi-Way Partitioning --- p.46Chapter 4.5 --- Modified Fan-out Free Cone Decomposition --- p.47Chapter 4.6 --- Clustering Phase --- p.48Chapter 4.7 --- Partitioning Phase --- p.51Chapter 4.8 --- The Acyclic Constraint --- p.52Chapter 4.9 --- Experimental Results --- p.57Chapter 4.10 --- Chapter Summary --- p.58Chapter 5 --- Network Flow Based Multi-way Partitioning --- p.61Chapter 5.1 --- Preliminaries --- p.61Chapter 5.2 --- Notations and Definitions --- p.62Chapter 5.3 --- Net Modelling --- p.63Chapter 5.4 --- Previous Works on Network Flow Based Partitioning --- p.64Chapter 5.4.1 --- Network Flow Based Min-Cut Balanced Partitioning [4] --- p.65Chapter 5.4.2 --- Network Flow Based Circuit Partitioning for Time-multiplexed FPGAs [5] --- p.66Chapter 5.5 --- Proposed Net Modelling --- p.70Chapter 5.6 --- Partitioning Properties Based on the Proposed Net Modelling --- p.73Chapter 5.7 --- Partitioning Step --- p.75Chapter 5.8 --- Constrained FM Post Processing Step --- p.79Chapter 5.9 --- Experiment Results --- p.81Chapter 6 --- Conclusion --- p.86Bibliography --- p.8

Strong component-based methodology for facility layout design

Among many issues involved within the field of manufacturing systems, the design of facilities layout is an ongoing and interesting research field, where new solutions and approaches are sought to determine the appropriate location and physical organisation of the resources in manufacturing systems. Issues such as space, material handling, machine placement and orientation, utilities location, and environmental factors are important features that may be considered when establishing the requirements of a facility layout design. The facility layout design can be thought of in terms of interconnecting work centres that can be represented by a set of interrelated vertices in a graph. Directed graphs can be used to characterise each product operation sequence, which combined into a single directed graph, be used to represent appropriately a layout design. Doing this together with the material handling system requirements, will allow better facilities planning and may improve process sequences that should be reflected in better designs. The Strong Component Based Methodology proposed here, obtains a graphical structure from the integration of various products and using their operation sequences to produce a relationship diagram. The attributes of the resultant structure are used to create this diagram. The objective is to obtain layouts that minimise material handling, that is, as close as possible to that which can be obtained with dedicated facilities for each product family but without the capital costs involved in the case of the latter. Encouraging results have been obtained by considering strong components, a feature of directed graphs, because less computational resources than in the case of many previous methods, which use Quadratic Assignment Problem approaches, are required to formulate and produce a relationship diagram. Moreover, this approach produces faster designs than other graph theoretic approaches because it avoids using planar and dual graphs. These characteristics allow the Strong Components approach to address more complex situations and obtain comparable or better solutions than previous approaches. The proposed Strong Component approach is a robust and versatile tool to support layout designs. It is a robust methodology because it provides efficient relationship diagrams even in cases when the resultant structure has relatively few strong component relationships. It is a versatile approach, because it can address various situations and can use different criteria to create layouts. Thus, the proposed approach offers effective-economical relationship diagrams to produce the same set of products as when producing them in dedicated facilities

A two-stage structural optimisation and thermal discretisation of non-convective structured insulators: applications in granular-solid structures by additive manufacturing technology

A systematic design procedure for characterising the strength and insulation requirements of a modular unit structure from additive manufacturing has been presented. The proposed 'two-stage' method consists of structural optimisation and thermal 'discretisation', through use of the Metamorphic Development (MD) and Discretisation by Partitioning Method (DbPM), respectively. A structural layout optimisation method of a consolidated granular-solid structure for strength requirements is demonstrated. The reliability of the layout optimized design solution tested using experiments and finite element analysis (PEA) are reproduced with reasonable accuracy. Layout optimisation yielded 40% savings in build material, whilst satisfying the targeted deflection. [Continues.

A complete design path for the layout of flexible macros

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