The main aim of this Thesis is to examine how the rock mass and intact rock properties influence the excavatability of rock in surface mine. One of the most important decisions in the design of surface mine is the selection of mine equipment and plant. Now that increasing effort is being invested in the design and manufacture of continuous surface miners it is appropriate to examine how their performance can be related to the physical properties of the rock mass and intact rock.Over the years many attempts have been made to develop a means of assessing the excavatability of rock. Most of them are based on an empirical rating system whilst some authorities still propose the use of seismic velocity as a direct predictor of the rippability of a rock mass. On the other hand there are a number of classical models which have been developed to define the cutting force required at the pick or tooth of continuous miners.Whilst these methods have been applied with various degrees of success to the design of excavation systems there is no generally acceptable method of defining the excavatability or cuttability of a rock mass in terms of the machine power required to generate a particular rate of production.An attempt is made to overcome this deficiency by recording the intact and rock mass properties at Limestone quarry in Retznei, Austria; Openpit Gold Mines in Meekatharra and Mt Gibson of Western Australia and Openpit Coal Mine in Air Laya, Indonesia, where VASM-2D and Bucket Wheel Excavator O&K SchRs(800/1.2)15 or O&K S630 were in use in the first mine sites and Air Laya respectively to use this data to examine the relationships between the relevant dimensionless groups developed from a dimensional analysis of the problem.The dimensionless groups are obtained by examining the factors which influence the productivity of a surface miner. These include intact rock and rock ++ / mass properties, and machine power required for a particular rate of production and lead to the development of dimensionless groups namely, Rock Cuttability Index (RCI), Rock Mass Factor (RMF), Brittleness Index (BI), Rock Excavatability Index. The monitoring of machine power was carried out at Mt. Gibson and Air Laya mines.As a part of this study, field seismic tests were carried out at Mt. Gibson and Air Laya with the intention of seeking the most appropriate method of this type of test and analysis for excavation purposes. The test results indicate that borehole tests are the most promising and the output of seismic velocity obtained from a built-in program seismograph needs further thorough examination.The analysis of field data at all the sites proved that the most appropriate measure of discontinuities in the rock mass is the mean distance between discontinuities in a direction parallel to the cutting direction of the machine.Since the lateritic rock mass is different to other ordinary rock masses, a modified RMR is proposed. This is done by adjusting classification criteria on spacing and condition of discontinuity. The results proved that the discontinuity spacing obtained from the proposed method warrants wide application of the power cutting model developed.The RMR, Q-System and Excavatability Index are used to assess the performance of the continuous surface miners investigated. The results indicated that the Excavatability Index is the most acceptable criterion for the excavatability assessment.The outcome of this research has confirmed the significance of the RCI as a predictor of cutting performance of mechanical machines. The relationship between the RCI and REI can be used to good effect in analysing the performance of operating machines. A good example of this is given in the analysis of the performance of the BWE at the Mae Moh mine in Thailand.

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O desenvolvimento de produtos é reconhecido como um processo desafiador em todas as empresas. No entanto, como aeronaves são muito complexas e devem atender à uma multiplicidade de requisitos interligados, seu processo de desenvolvimento representa um desafio ainda maior. Assim, entre os diferentes requisitos a serem atendidos por uma nova aeronave, há os requisitos de custo, desempenho e sustentabilidade. As propriedades de massa da aeronave estão relacionadas com o cumprimento destes três requisitos, dessa maneira, é essencial que as estimativas iniciais de propriedades de massa sejam as mais realistas possíveis e que estas sejam rigorosamente controladas durante as fases posteriores de desenvolvimento. As principais propriedades de massa de uma aeronave são: peso, centro de gravidade, momentos e produtos de inércia. A gestão de propriedades de massa tem diferentes características dependendo da fase de desenvolvimento do produto. O principal objetivo deste trabalho é identificar as principais características da gestão das propriedades de massa durante o desenvolvimento de aeronaves, identificar oportunidades e propor pontos de melhoria no processo executado por uma empresa desenvolvedora de aeronaves. Assim, foi realizada a síntese da revisão da literatura de maneira a permitir a identificação das características e variáveis críticas do processo, considerando suas principais dimensões: atividades e entregas, papéis e responsabilidades, estratégias e metas, e recursos e ferramentas Posteriormente um estudo de caso estruturado foi conduzido em uma empresa desenvolvedora de aeronaves de maneira a identificar divergências entre a síntese do processo de gestão de propriedades de massa e a forma com que esta gestão é conduzida na prática. As divergências encontradas foram analisadas e geraram propostas de melhorias no processo executado na prática. Esta é uma pesquisa descritiva e a metodologia adotada é o estudo de caso participativo, uma vez que a autora participou do processo de desenvolvimento de aeronaves por três anos. Os resultados deste trabalho destacam as diferenças entre teoria e práticas de gestão de propriedades de massa, considerando principalmente a integração técnica, estratégia e responsabilidades no processo de desenvolvimento de aeronaves. / The product development is a challenging process for any product. However, as aircraft are highly complex and should comply with a multiplicity of interconnected requirements, their design process represents a challenge of the highest order. Hence, among the various requirements to be met by a new aircraft, there are cost, performance and sustainability requirements. The mass properties of the aircraft are related to the fulfillment of these three requirements, so it is crucial that realistic estimates of aircraft mass properties be used during early conceptual design, and that it be strictly controlled during later stages of design. The main mass properties of an aircraft are: weight, center of gravity, moments and products of inertia. The Mass Properties Management (MPM) is an iterative process that has to deal with information in the lowest level of the system and yet be robust enough to answer in the aircraft level, it shall provide accurate and timely mass properties data for making design optimization decisions. The MPM has different characteristics depending on the product development phase; it has to be adapted as the maturity of the aircraft increases and it depends on the technical integration status of the development. The main objective of this work is to analyze the MPM characteristics in the aircraft development process, and identify opportunities and propose best practices for MPM process improvement in an aircraft manufacturer. A synthesis of literature review was conducted and the primary result is the understanding of the mass properties relationship within the aircraft development process, considering its main perspectives: activities and deliverables, roles and responsibilities, goals and tools. This is a descriptive research and the methodology adopted is the longitudinal participatory case study, since the author has been participating of the MPM during an aircraft development process for three years. A synthesis of the MPM main characteristic is proposed to represent the perspective mentioned, in order to allow comparing it with the findings of the case study. Research instruments used were a logbook and a questionnaire for interviewing major stakeholders of the product development process. The findings of this work highlight the differences between MPM theory and practices, mainly considering technical integration, strategy and responsibilities in the aircraft development process.

O desenvolvimento de produtos é reconhecido como um processo desafiador em todas as empresas. No entanto, como aeronaves são muito complexas e devem atender à uma multiplicidade de requisitos interligados, seu processo de desenvolvimento representa um desafio ainda maior. Assim, entre os diferentes requisitos a serem atendidos por uma nova aeronave, há os requisitos de custo, desempenho e sustentabilidade. As propriedades de massa da aeronave estão relacionadas com o cumprimento destes três requisitos, dessa maneira, é essencial que as estimativas iniciais de propriedades de massa sejam as mais realistas possíveis e que estas sejam rigorosamente controladas durante as fases posteriores de desenvolvimento. As principais propriedades de massa de uma aeronave são: peso, centro de gravidade, momentos e produtos de inércia. A gestão de propriedades de massa tem diferentes características dependendo da fase de desenvolvimento do produto. O principal objetivo deste trabalho é identificar as principais características da gestão das propriedades de massa durante o desenvolvimento de aeronaves, identificar oportunidades e propor pontos de melhoria no processo executado por uma empresa desenvolvedora de aeronaves. Assim, foi realizada a síntese da revisão da literatura de maneira a permitir a identificação das características e variáveis críticas do processo, considerando suas principais dimensões: atividades e entregas, papéis e responsabilidades, estratégias e metas, e recursos e ferramentas Posteriormente um estudo de caso estruturado foi conduzido em uma empresa desenvolvedora de aeronaves de maneira a identificar divergências entre a síntese do processo de gestão de propriedades de massa e a forma com que esta gestão é conduzida na prática. As divergências encontradas foram analisadas e geraram propostas de melhorias no processo executado na prática. Esta é uma pesquisa descritiva e a metodologia adotada é o estudo de caso participativo, uma vez que a autora participou do processo de desenvolvimento de aeronaves por três anos. Os resultados deste trabalho destacam as diferenças entre teoria e práticas de gestão de propriedades de massa, considerando principalmente a integração técnica, estratégia e responsabilidades no processo de desenvolvimento de aeronaves. / The product development is a challenging process for any product. However, as aircraft are highly complex and should comply with a multiplicity of interconnected requirements, their design process represents a challenge of the highest order. Hence, among the various requirements to be met by a new aircraft, there are cost, performance and sustainability requirements. The mass properties of the aircraft are related to the fulfillment of these three requirements, so it is crucial that realistic estimates of aircraft mass properties be used during early conceptual design, and that it be strictly controlled during later stages of design. The main mass properties of an aircraft are: weight, center of gravity, moments and products of inertia. The Mass Properties Management (MPM) is an iterative process that has to deal with information in the lowest level of the system and yet be robust enough to answer in the aircraft level, it shall provide accurate and timely mass properties data for making design optimization decisions. The MPM has different characteristics depending on the product development phase; it has to be adapted as the maturity of the aircraft increases and it depends on the technical integration status of the development. The main objective of this work is to analyze the MPM characteristics in the aircraft development process, and identify opportunities and propose best practices for MPM process improvement in an aircraft manufacturer. A synthesis of literature review was conducted and the primary result is the understanding of the mass properties relationship within the aircraft development process, considering its main perspectives: activities and deliverables, roles and responsibilities, goals and tools. This is a descriptive research and the methodology adopted is the longitudinal participatory case study, since the author has been participating of the MPM during an aircraft development process for three years. A synthesis of the MPM main characteristic is proposed to represent the perspective mentioned, in order to allow comparing it with the findings of the case study. Research instruments used were a logbook and a questionnaire for interviewing major stakeholders of the product development process. The findings of this work highlight the differences between MPM theory and practices, mainly considering technical integration, strategy and responsibilities in the aircraft development process.

The determination of an aircraft's mass properties is critical during its conceptual design phase. Obtaining reliable mass property information early in the design of an aircraft can prevent design mistakes that can be extremely costly further along in the development process. In this thesis, several methods are presented in order to automatically calculate the mass properties of aircraft structural components and fuel stored in tanks. The first method set forth calculates the mass properties of homogenous solids represented by polyhedral surface geometry. A newly developed method for calculating the mass properties of thin shell objects, given the same type of geometric representation, is derived and explained. A methodology for characterizing the mass properties of fuel in tanks has also been developed. While the concepts therein are not completely original, the synthesis of past research from diverse sources has yielded a new comprehensive approach to fuel mass property analysis during conceptual design. All three of these methods apply to polyhedral geometry, which in many cases is used to approximate NURBS (Non-Uniform Rational B-Spline) surface geometry. This type of approximate representation is typically available in design software since this geometric format is conducive to graphically rendering three-dimensional geometry. The accuracy of each method is within 10% of analytical values. The methods are highly precise (only affected by floating point error) and therefore can reliably predict relative differences between models, which is much more important during conceptual design than accuracy. Several relevant and useful applications of the presented methods are explored, including a methodology for creating a CG (Center of Gravity) envelope graph. / Master of Science

The Cal Poly Spacecraft Simulator is currently being developed for future testing and verifying theoretical control applications. This paper details the effort to balance the platform and remove undesired external torque from the system using System Identification technique developed by Patrick Healy. Since the relationship between the input and output of the system is linear, the least square method is proposed to identify the mass properties and location of center of mass of the system. The tests use four sine wave generators that are out of phase with different amplitudes as the inputs to excite various structural modes of the system. The outputs, angular rates of the platform, are measured by the newly implemented LN-200 Inertial Measurement Unit that helps reducing the measurement noise. Two test cases of 90o yaw rotations with the identified inertia were performed and validated against the computer simulation model; and the result shows that the test cases trajectories followed closely with the computer simulation model.