Process Analysis of Laser Beam Cladding

2000 ◽  
Vol 123 (4) ◽  
pp. 609-614 ◽  
Author(s):  
A. F. H. Kaplan ◽  
G. Groboth
Keyword(s):  
Laser Beam ◽  
Process Model ◽  
Process Analysis ◽  
Single Step ◽  
Balance Equations ◽  
Energy Redistribution ◽  
Geometrical Properties ◽  
Clad Layer ◽  
Powder Mass ◽  
Balance Equations Of Energy

The technology of laser beam cladding of metals by single-step powder delivery is analyzed with a process model which is based on balance equations of energy and mass. Effects like powder heating, clad layer formation, substrate dilution and overlapping of tracks are discussed in dependence of the process parameters. In particular, the powder catchment efficiency and the beam energy redistribution in the material can be optimized by the powder mass flow rate and by the geometrical properties of the beam and of the powder jet.

Design and Operational Analyses of Activated Sludge Processes Using Respirometrically Calibrated Models

1992 ◽  
Vol 26 (3-4) ◽  
pp. 753-762 ◽  
Author(s):  
A. F. Rozich
Keyword(s):  
Activated Sludge ◽  
Model Calibration ◽  
Process Model ◽  
Process Analysis ◽  
Case Histories ◽  
Model Case ◽  
Operational Strategies ◽  
Analysis Methodology ◽  
Technical Basis ◽  
Activated Sludge Processes

The purpose of this paper is to present the background and examples of methodology which enable environmental engineers and scientists to analyze activated sludge processes much more effectively than is otherwise possible with conventional approaches. Good process analyses are key for devising optimal design and operational strategies. The key features to the technique presented herein are the field-proven predictability of the model and the methodology for collecting data needed for calibrating the process model. Case histories prove the predictability of the model that is associated with the process analysis approach. The advantage of the approach advocated herein is the use of respirometric techniques to calibrate the model. These methods enable the process analyst to collect the requisite data for model calibration in twenty-four hours or less. This feature enables one to use this process analysis methodology for both design and operational applications. The paper will present the technical basis for the process model and how respirometric methods are utilized to compute biokinetic constants in a manner which is consistent with kinetic theory. Case histories will be discussed that demonstrate the predictability of the modeling approach and demonstrate the utility of this tool for process analysis.

scholarly journals Steel Sheets Laser Lap Joint Welding—Process Analysis

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2258 ◽  
Author(s):  
Hubert Danielewski ◽  
Andrzej Skrzypczyk
Keyword(s):  
Numerical Simulation ◽  
Laser Beam ◽  
Steel Sheet ◽  
Process Analysis ◽  
Welding Process ◽  
Parameters Estimation ◽  
Welding Parameters ◽  
Lap Joint ◽  
Beam Radiation ◽  
Keyhole Effect

This article presents the results of steel-sheet lap-joint-welding using laser beam radiation. The use of a laser beam and keyhole effect for deep material penetration in lap joint welding was presented. Thermodynamic mechanism of laser welding is related to material properties and process parameters. Estimation of welding parameters and joint properties’ analysis was performed through numerical simulation. The article presents a possibility of modeling laser lap-joint welding by using Simufact Welding software based on Marc solver and thermo-mechanical solution. Numerical calculation was performed for surface and conical volumetric heat sources simulating laser absorption and keyhole effect during steel sheet welding. Thermo-mechanical results of fusion zone (FZ), heat-affected zone (HAZ) and phase transformations calculated in numerical simulation were analyzed. The welding parameters for partial sealed joint penetration dedicated for gas piping installations were estimated from the numerical analysis. Low-carbon constructional steel was used for numerical and experimental analyses. A trial joint based on the estimated parameters was prepared by using a CO2 laser. Numerical and experimental results in the form of hardness distributions and weld geometry were compared. Metallographic analysis of the obtained weld was presented, including crystallographic structures and inclusions in the cross section of the joint.

A Process Model and Data Mining to Support Designing Families of Services

2007 ◽  
Author(s):  
Seung Ki Moon ◽  
Timothy W. Simpson ◽  
Soundar R. T. Kumara
Keyword(s):  
Data Mining ◽  
Process Model ◽  
Process Analysis ◽  
Product Family ◽  
Cost Effective ◽  
Service Development ◽  
Product Family Design ◽  
New Service Development ◽  
Recent Trends

Product family design is a cost-effective way to achieve mass customization by allowing highly differentiated products to be developed from a common platform while targeting individual products to distinct market segments. Recent trends seek to apply and extend principles from product family design to new service development. In this paper, we extend concepts from platform-based product family design to create a novel methodology for module-based service family design. The new methodology helps identify a service platform along with variant and unique modules in a service family by integrating service-based process analysis, ontologies, and data mining. A function-process matrix and a service process model are investigated to define the relationships between the service functions and the service processes offered as part of a service. An ontology is used to represent the relationships between functional hierarchies in a service. Fuzzy clustering is employed to partition service processes into subsets for identifying modules in a given service family. The clustering result identifies the platform and its modules using a platform level membership function. We apply the proposed methodology to determine a new platform using a case study involving a family of banking services.

Demand-driven Evolution of IT Systems in Healthcare

2005 ◽  
Vol 44 (01) ◽  
pp. 4-10 ◽  
Author(s):  
F. Buessecker ◽  
H. Herlofsen ◽  
F. Hinrichs ◽  
T. Zeiler ◽  
K. A. Kuhn ◽  
...  
Keyword(s):  
Change Management ◽  
Formal Methods ◽  
Process Model ◽  
Reference Model ◽  
Process Analysis ◽  
Application Development ◽  
System Evolution ◽  
It Systems ◽  
Driven System ◽  
It Application

Summary Objectives: To analyze and to optimize interdisciplinary clinical processes, to introduce an IT-supported model for demand-driven system evolution in healthcare, and to demonstrate the feasibility of the approach for a clinical example and to present an evaluation. Methods: System evolution and change management are viewed as two sides of the same coin, thus formal methods for process analysis and IT system evolution were embedded into a goal-oriented change management model. Based on a process model, a Failure Mode and Effects Analysis (FMEA) and a computer simulation were performed. A tool for rapid application development (RAD) was used to incrementally improve the healthcare information system according to newly arising needs. Results: Each of the formal methods used contributed to the successful reorganization of the interdisciplinary clinical process. An evaluation demonstrated significant improvements. An integrated IT application was implemented to support the optimized process. Conclusions: Process improvement is feasible and effective when formal methods for process analysis and requirements specification are used in a reasonable and goal-oriented way. It might be necessary to trade off costs and benefits or simplify a given method in the context of a particular project. As the same information is utilized in different tools, it is supposed that the efforts for process analysis, documentation and implementation of adapted applications could be reduced if different tools were integrated and based on a single coherent reference model for description of clinical processes.

scholarly journals Generating tensions: A multilevel, process analysis of organizational change

2017 ◽  
Vol 17 (1) ◽  
pp. 8-37 ◽  
Author(s):  
Alexia Panayiotou ◽  
Linda L Putnam ◽  
George Kassinis
Keyword(s):  
Organizational Change ◽  
Process Model ◽  
Qualitative Data ◽  
Process Analysis ◽  
Music Industry ◽  
Unintended Consequences ◽  
Dialectical Tensions ◽  
Ongoing Process ◽  
Start Up ◽  
Organizational Levels

Working within a Bakhtinian perspective of relational dialectical tensions, this study seeks to elaborate on current organizational change theories through a rich set of qualitative data collected on an Internet start-up that revolutionized the music industry. Following the company for 12 years, we focused on the tensions arising during the company’s development and on the responses to these tensions. Our results indicate that with a process model, tensions and decisions develop in a reflexive relationship, which shows that change happens, not in spite of unintended consequences, but because of the unintended consequences of the decisions enacted. We show that change is not always the result of deliberate intentions, conscious choices, and purposeful actions of individuals, but rather as an ongoing process that evolves through countervailing dynamics at multiple organizational levels. Tensions and responses to them are pivotal to this process of changing and should be analyzed as directional markers for future oppositional struggles. Consistent with the Bakhtinian position, we find that change occurs within the interplay of tensions as actors live out struggles and decisions in the midst of organizing.

Process Analysis of Ocean Thermal Energy Used for Desalination

2013 ◽  
Vol 724-725 ◽  
pp. 1242-1248
Author(s):  
Zhi Jiang Jin ◽  
Hao Wang
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Process Model ◽  
Process Analysis ◽  
Conventional Technique ◽  
Ocean Energy ◽  
Unit Energy ◽  
Lower Temperature ◽  
Ocean Thermal Energy ◽  
Direct Use

Ocean thermal energy (OTE) is a kind of ocean energy with a large development potential. In this paper, a new method making direct use of OTE for desalination was put forward and its principles and working process were also expounded. Firstly, this paper established the relevant process model of OTE desalination system. The system used OTE to maintain a vacuum and seawater could be evaporated at a much lower temperature and with less energy than conventional technique. Secondly, a parametric study was carried out quantitatively. It analyzed the influence on the system’s operation of three main parameters (temperature, mass flow and energy consumption). Finally, this paper improved the energy efficiency of the system. The lowest unit energy consumption could reach 4.54kWh/m3. The results indicate the feasibility of OTE used for desalination and its competitiveness against common solar desalination method.

scholarly journals Enhancing the Joining Properties of Biodegradable PLA from Fused Deposition Modeling by Infrared Laser Irradiation

2020 ◽  
Author(s):  
J.M. Vazquez-Martinez ◽  
D. Piñero ◽  
J. Salguero ◽  
M. Batista
Keyword(s):  
Additive Manufacturing ◽  
Laser Beam ◽  
Fused Deposition Modeling ◽  
Tensile Tests ◽  
Infrared Laser ◽  
Single Step ◽  
Step Method ◽  
Modeling Technology ◽  
Fused Deposition ◽  
Welding Processes

The development of high complexity geometry parts is one of the main goals of the additive manufacturing technology. However, the failure of printed structures and the joining of different parts to create complex assemblies represents a real challenge in the research of efficient and sustainability techniques for the permanent assembly of polymers. Laser welding processes have been used as a single step method to join metals until years ago. Nowadays, the growing trend in the use of thermoplastics for additive manufacturing has led to the need to adapt this technique to materials with a very specific nature and more sensitive to thermal effects. Also, the possibility of transmitting the laser beam through transparent polymer layers allows to focus the energy supply on internal sections of the assembled components. In this research, an infrared laser marking system was used to join two different samples of polylactic acid manufactured by fused deposited modeling technology. In order to increase the effectiveness of the bonding process, a transparent and a dark sample have been used as assembly material, focusing the laser beam on the interface area of the two parts. By means of tensile tests, dimensional measurement and the use of optical microscopy techniques, a basis was established that links the supplied energy by laser to the joining performance.

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