scholarly journals N-policy for a multi-component machining system with imperfect coverage, reboot and unreliable server

2014 ◽  
Vol 2 (1) ◽  
pp. 457-476 ◽  
Author(s):  
Madhu Jain ◽  
Chandra Shekhar ◽  
Varsha Rani
Keyword(s):  
Unreliable Server ◽  
Machining System ◽  
Imperfect Coverage

scholarly journals Multi-Machine Repairable System with One Unreliable Server and Variable Repair Rate

Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1299
Author(s):  
Shengli Lv
Keyword(s):  
Steady State ◽  
Transient State ◽  
Repairable System ◽  
Repair Rate ◽  
Numerical Illustration ◽  
Transform Method ◽  
Unreliable Server ◽  
Busy Time ◽  
The Mean ◽  
Mean Time

This paper analyzed the multi-machine repairable system with one unreliable server and one repairman. The machines may break at any time. One server oversees servicing the machine breakdown. The server may fail at any time with different failure rates in idle time and busy time. One repairman is responsible for repairing the server failure; the repair rate is variable to adapt to whether the machines are all functioning normally or not. All the time distributions are exponential. Using the quasi-birth-death(QBD) process theory, the steady-state availability of the machines, the steady-state availability of the server, and other steady-state indices of the system are given. The transient-state indices of the system, including the reliability of the machines and the reliability of the server, are obtained by solving the transient-state probabilistic differential equations. The Laplace–Stieltjes transform method is used to ascertain the mean time to the first breakdown of the system and the mean time to the first failure of the server. The case analysis and numerical illustration are presented to visualize the effects of the system parameters on various performance indices.

Usability of Web-Based Design and Manufacturing Systems: Case Study of Micro Machining

2005 ◽  
Author(s):  
Hyung-Jung Kim ◽  
Won-Shik Chu ◽  
Hyuk-Jin Kang ◽  
Sung-Hoon Ahn ◽  
Dong-Soo Kim ◽  
...  
Keyword(s):  
Manufacturing Systems ◽  
Processing Time ◽  
Micro Machining ◽  
User Friendliness ◽  
Web Based ◽  
Design And Manufacturing ◽  
Cad Cam ◽  
Machining System ◽  
Web Based System ◽  
The Web

In this paper, web-based design and manufacturing systems are compared with a commercial CAD/CAM system from the point of usability. The web-based systems included in this study were MIcro Machining System (MIMS) and SmartFab. In the MIMS architecture, a 3D model in STL format was read via a web browser, sent to the web server for toolpath planning, and NC codes were generated to be fed back to the designer through the web connection. In the SmartFab system, SolidWorks was used as the design interface with provided modified menus for micro machining. These additional menus were created by SolidWorks API that also provided web-based links to the toolpath planner. In the commercial CAD/CAM case, without using any web connection, SolidWorks or CATIA was used for design, and PowerMill was used as a CAM tool. For each design and manufacturing system, accessibility, user-friendliness, toolpath-reliability, and processing time were compared. Total 91 students tested these systems in undergraduate CAD class, and the feedback showed better performance of the web-based system in accessibility, user-friendliness, and processing time. However, reliability of the web-based system showed necessity of further improvement.

scholarly journals Implementation of a micro-electrical discharge machining system to fabricate TiO2 nanocolloid

Mechatronics ◽  
2021 ◽  
Vol 79 ◽  
pp. 102649
Author(s):  
Kuo-Hsiung Tseng ◽  
Kuo-Hui Chen ◽  
Chaur-Yang Chang ◽  
Yagus Cahyadi ◽  
Meng-Yun Chung
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Micro Electrical Discharge Machining ◽  
Machining System

Videooptical Surface Shape and Integrity Estimation in Robots Machining

2013 ◽  
Vol 332 ◽  
pp. 270-275 ◽  
Author(s):  
Tadeusz Mikolajczyk
Keyword(s):  
Surface Roughness ◽  
Industrial Robot ◽  
Surface Shape ◽  
Engineering System ◽  
Machined Surface ◽  
Reflectivity Method ◽  
Machining System ◽  
Grinding Tool ◽  
Smart Machining ◽  
Usb Camera

Paper shows system to surface shape and quality control in machining using industrial robot. To surface control videooptical methods were used. Surface shape was controlled using the special reverse engineering system. To surface roughness measure machined surface reflectivity method was used. Used own constructions non contact system was equipped with red laser light and USB camera. Wrist of robot was equipped with grinding tool. In paper shows some algorithms of presented processes. Shown too examples of experiments results in surface roughness measure in start end of grinding process. First trials of presented system shows possibility to build smart machining system for finishing of surface with unknown shape.

Hybrid CO2 Laser/Waterjet Machining of Polycrystalline Diamond Substrate: Material Separation Through Transformation Induced Controlled Fracture

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Dinesh Kalyanasundaram ◽  
Andrea Schmidt ◽  
Pal Molian ◽  
Pranav Shrotriya
Keyword(s):  
Co2 Laser ◽  
Polycrystalline Diamond ◽  
Substrate Material ◽  
Stress Fields ◽  
Separation Mechanism ◽  
Raman Spectrometry ◽  
Waterjet Machining ◽  
Machining System ◽  
Material Separation ◽  
Controlled Fracture

This paper presents a combined experimental and computational investigation of a novel material separation mechanism in polycrystalline diamond (PCD) substrates. A hybrid CO2 laser/waterjet (CO2-LWJ) machining system that combines a CO2 laser for localized heating and an abrasive-free waterjet to rapidly quench the heated area is utilized for cutting experiments on PCD substrates. Scanning electron microscopy (SEM) and micro-Raman spectrometry characterization performed on the cut surfaces show that cut surfaces were divided into two zones—a thin transformed zone near the top where the PCD grains have transformed to graphite and diamond-like carbon; and a fracture zone with the same composition as-received substrate. The experimental results indicate that the PCD substrates were cut through a “score and snap” mechanism—laser heating leads to localized damage and phase transformation of surface layers; and subsequently, stress fields developed due to constrained expansion of transformed material and waterjet quenching act on the laser made “score” to propagate crack through the thickness. Analytical solutions for thermal diffusion and force equilibrium are used to determine the temperature and stress fields in the PCD substrate during CO2-LWJ cutting. Fracture mechanics analysis of crack propagation is performed to demonstrate the feasibility of the “score and snap” mechanism for cutting of PCD substrates.

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