Search results for "Mach"
showing 10 items of 3360 documents
Analysis of Offshore Knuckle Boom Crane - Part One: Modeling and Parameter Identification
2013
This paper presents an extensive model of a knuckle boom crane used for pipe handling on offshore drilling rigs. The mechanical system is modeled as a multi-body system and includes the structural flexibility and damping. The motion control system model includes the main components of the crane's electro-hydraulic actuation system. For this a novel black-box model for counterbalance valves is presented, which uses two different pressure ratios to compute the flow through the valve. Experimental data and parameter identification, based on both numerical optimization and manual tuning, are used to verify the crane model. The demonstrated modeling and parameter identification techniques target…
Environmental Comparison between a Hot Extrusion Process and Conventional Machining Processes through a Life Cycle Assessment Approach
2014
Nowadays manufacturing technologies have to be evaluated not only for the technical features they can provide to products, but also considering the environmental perspective as well. As long as the technological feasibility of a given process is guaranteed, processes minimizing resources and energy consumption have to be selected for manufacturing. With respect to this topic, the research studies in the domain of metal processing technologies predominantly focus on conventional material removal processes as milling and turning. Despite some exceptions, many other non-machining technologies, such as metal forming processes, are still not well documented in terms of their energy and resource …
Assessment of Cost and Energy Requirements of Electron Beam Melting (EBM) and Machining Processes
2017
Additive Manufacturing is under the spotlight as potential disruptive technology, particularly for the production of complex-shaped structural metallic components. However, the actual AM process capabilities present some limitations in achieving the strict part quality requirements imposed by the aerospace and automotive sectors. Therefore, the integration of AM and conventional manufacturing represents an emerging scenario to be investigated. In this paper, a pure machining process and a hybrid production route (based on EBM and finish machining) are compared. The influence of material usage-related factors on costs and energy demand is discussed. The results prove that, despite precise pr…
A Banki–Michell turbine for in-line water supply systems
2017
The design of a novel Banki-Michell type turbine, to be located in existing water pipelines, is proposed. The turbine has a very efficient diffuser which allows the turbine to be compact and, most important, to have in-line flanges for minimal piping modifications at existing sites. This turbine combines a simple geometry with stable efficiency in a wide range of water discharges. The design procedure estimates the outer diameter of the impeller, its width and the geometry of the diffuser. A series of experimental tests has been carried out to measure the efficiency of the proposed turbine prototype. The turbine was tested in two different configurations, with and without rotational velocit…
Determination of temperature distribution in the cutting zone using hybrid analytical-FEM technique
2006
Abstract In this study, the temperature distribution in the cutting zone was determined by integrating thermal analytical and simulation models of orthogonal cutting process with uncoated and coated carbide tools. Primarily, 2D FEM simulations were run to provide numerical solutions of temperatures occurring at different points through the chip/tool contact region and the coating/substrate boundary under defined cutting conditions. In addition, an analytical model for heat transfer in the cutting tool and its partitioning, proposed in References [W. Grzesik, P. Nieslony, Physics based modelling of interface temperatures in machining with multilayer coated tools at moderate cutting speeds, I…
Machining Economics in FMS by a Fuzzy Approach
1995
Abstract In a conventional manufacturing system, cutting parameters have to be fixed in order to pursue the economical and productive target related to each cutting operation. In a Flexible Manufacturing System (FMS), as a consequence of the unbalanced workload due to the mutual interaction among the shared resources, the optimization of each operation does not allow the optimum of the global production system to be reached. A fuzzy programming model is developed in this paper in order to select cutting speeds of the operations in the production plan as a satisfying compromise solution between single operation and the integrated system targets.
Computer assisted techniques for the incremental forming technology
2013
The Asymmetric single point incremental forming (ASPIF) is a manufacturing technology with a high degree of novelty. Even if there are a significant number of research results reported in the literature, the industry has not been very enthusiastic to adopt and implement it on large scale. One of the main reasons for that is the lack of specific computer aided techniques and tools, which could be used to design and optimize the ASPIF process. The paper presents some methods to overcome this drawback, either by using some general purpose computer assisted tools or by developing new simple, yet effective methods. The proposed methods can be used in the preparation stage of computer automated m…
Tuning Decision Support Toolsfor Environmentally Friendly Manufacturing Approach Selection
2017
Awareness about the environmental performance of manufacturing approaches has arisen. Comparative analyses of different manufacturing approaches as well as decision support methods should be developed in the field of metal shaping processes. The present paper aims at tuning a decision support tool for identifying when mass conserving approaches (forming based) are actually preferable over machining processes for manufacturing aluminum based components. A full LCA is developed for comparing the environmental performance of forming and machining approaches as the batch size and geometry complexity hang. The impact of the used metric on the comparative results is analyzed. Results reveal that …
Event Reconstruction
2014
Event reconstruction is one of the most important step in digital forensic investigations. It allows investigators to have a clear view of the events that have occurred over time. Event reconstruction is a complex task which requires exploration of a large amount of events due to the pervasiveness of new technologies nowadays. Any evidence produced at the end of the investigative process must also meet the requirements of the courts, such as reproducibility, verifiability, validation, etc. After defining the most important concepts of event reconstruction, a survey of the challenges of this field and solutions proposed so far is given in this chapter. Irish Research Council Science Foundati…
Identification of a static tool force model for robotic face milling
2014
In this paper two different process models which can predict the mean value components of the tool forces when milling aluminium, bronze and steel with an industrial robot have been estimated. The parameters in the process models were depth and width of cut, while feedrate and cutting speed were found from the tool manufacturer's datasheets. The models were estimated from a large set of machining experiments. Different measurement sets were used for parameter estimation and for model verification. The estimated models were found to be accurate. For the experiments in aluminium and the model using only the depth of cut as parameter, the average error was about 18N. For the model using both d…