Determination of Optimal Machining Conditions: A Coupled Uncertainty Model

1998 ◽  
Vol 122 (1) ◽  
pp. 206-214 ◽  
Author(s):  
S. S. Rao ◽  
Li Chen
Keyword(s):  
Optimization Process ◽  
Objective Functions ◽  
Machining Processes ◽  
Numerical Examples ◽  
Machining Conditions ◽  
Uncertainty Model ◽  
Empirical Relations ◽  
Computational Aspects

The problem of selecting optimal machining conditions, where the formulation involves the use of empirical relations, is considered. Since both randomness and fuzziness are associated with empirical relations, a coupled uncertainty model is proposed for manipulating these uncertainties. Equations are derived to establish the interrelation between the two types of uncertainties present in the objective functions and constraints of the optimization process. This permits a systematic handling of fuzziness in terms of randomness that is usually associated with experiments. The computational aspects of the approach are illustrated by two numerical examples dealing with the optimization of machining processes. [S1087-1357(00)70501-6]

Manipulation of Uncertainties in the Determination of Optimal Machining Conditions Under Multiple Criteria

1997 ◽  
Vol 119 (2) ◽  
pp. 186-192 ◽  
Author(s):  
Li Chen ◽  
S. S. Rao
Keyword(s):  
Experimental Data ◽  
Traditional Approach ◽  
Fuzzy Model ◽  
Computational Approach ◽  
Optimization Process ◽  
Empirical Equations ◽  
Computational Optimization ◽  
Machining Conditions ◽  
Degree Of Certainty

In any real-world manufacturing situation, the problem of determining the optimum machining conditions involves not only empirical data but also imprecise information. Uncertain factors may need to be considered in the computational optimization process due to fuzziness present in the empirical equations and experimental data used. To manipulate the uncertainties in the optimization process, a fuzzy model is introduced and investigated. The fuzzy model quantifies the degree of certainty (or uncertainty) in the range 0 to 1. A numerical example is considered to illustrate the computational approach. The overall impact of the uncertain factors on the optimization process is assessed by comparing the present numerical results with those given by the traditional approach.

scholarly journals Study on Optimal Placement and Reasonable Number of Viscoelastic Dampers by Improved Weight Coefficient Method

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Ji-ting Qu ◽  
Hong-nan Li
Keyword(s):  
Mathematical Model ◽  
Weight Coefficient ◽  
Optimal Placement ◽  
Optimal Method ◽  
Analogy Method ◽  
Numerical Examples ◽  
Viscoelastic Dampers ◽  
Reasonable Number ◽  
Coefficient Method

A new optimal method is presented by combining the weight coefficient with the theory of force analogy method. Firstly, a new mathematical model of location index is proposed, which deals with the determination of a reasonable number of dampers according to values of the location index. Secondly, the optimal locations of dampers are given. It can be specific from stories to spans. Numerical examples are illustrated to verify the effectiveness and feasibility of the proposed mathematical model and optimal method. At last, several significant conclusions are given based on numerical results.

The Determination of the Three-Point Support Design of Machine Tool Based on iSIGHT

2014 ◽  
Vol 607 ◽  
pp. 342-345
Author(s):  
Sheng Hui Zhao ◽  
Xiao Chuang Zhu ◽  
Da Wei Zhang
Keyword(s):  
Machine Tool ◽  
High Precision ◽  
Multidisciplinary Optimization ◽  
Joint Surface ◽  
Objective Functions ◽  
Multi Objective Optimization ◽  
Support Design ◽  
Optimal Position ◽  
Point Support

In order to meet the requirements of high-precision machine tool, it has been an important factor to select an appropriate way to support the bed. By building a multidisciplinary optimization (MDO) process based on iSIGHT, this article select the deformation difference of the guides and the deformation difference of the joint surface between column and bed of the machine tool as the objective functions, and then conduct a multi-objective optimization (MOO) of the positional parameters of the three-point support. Eventually the optimization result is given and the optimal position of the three-point support is determined.

Positive stable realizations of discrete-time linear systems

2012 ◽  
Vol 60 (3) ◽  
pp. 605-616
Author(s):  
T. Kaczorek
Keyword(s):  
Transfer Function ◽  
Discrete Time ◽  
Sufficient Conditions ◽  
Asymptotically Stable ◽  
Numerical Examples ◽  
Discrete Time Systems ◽  
Necessary And Sufficient ◽  
Time Systems ◽  
Time Linear

Abstract The problem of existence and determination of the set of positive asymptotically stable realizations of a proper transfer function of linear discrete-time systems is formulated and solved. Necessary and sufficient conditions for existence of the set of the realizations are established. A procedure for computation of the set of realizations are proposed and illustrated by numerical examples.

Determination of Singularity-Free Zones in the Workspace of Planar 3-P̱RR Parallel Mechanisms

2006 ◽  
Vol 129 (6) ◽  
pp. 649-652 ◽  
Author(s):  
Mehdi Tale Masouleh ◽  
Clément Gosselin
Keyword(s):  
Parallel Mechanisms ◽  
Numerical Examples ◽  
Mathematical Derivation

This paper presents an algorithm for the determination of singularity-free zones in the workspace of the planar 3-P̱RR mechanism. The mathematical derivation of the algorithm is first given. Numerical examples are then included to demonstrate the application of the proposed approach.

scholarly journals Retailer’s optimal ordering policies for EOQ model with imperfective items under a temporary discount

2016 ◽  
Vol 26 (2) ◽  
pp. 219-240
Author(s):  
Wen Lin ◽  
Horng Chang
Keyword(s):  
Economic Order Quantity ◽  
Order Quantity ◽  
Objective Functions ◽  
Inventory Models ◽  
Screening Process ◽  
Numerical Examples ◽  
Closed Form Solutions ◽  
Eoq Model ◽  
Optimal Ordering ◽  
Special Order

In this article, we study inventory models to determine the optimal special order and maximum saving cost of imperfective items when the supplier offers a temporary discount. The received items are not all perfect and the defectives can be screened out by the end of 100% screening process. Three models are considered according to the special order occurs at regular replenishment time, non-regular replenishment time, and screening time of economic order quantity cycle. Each model has two sub-cases to be discussed. In temporary discount problems, in general, there are integer operators in objective functions. We suggest theorems to find the closed-form solutions to these kinds of problems. Furthermore, numerical examples and sensitivity analysis are given to illustrate the results of the proposed properties and theorems.

scholarly journals Improvement of Machining Processes: A Case Study

2019 ◽  
Vol 2 (3) ◽  
pp. 634-641
Author(s):  
Hakan Gökçe ◽  
Ramazan Yeşilay ◽  
Necati Uçak ◽  
Ali Teke ◽  
Adem Çiçek
Keyword(s):  
Material Removal ◽  
Current Practice ◽  
Complex Geometry ◽  
Vital Role ◽  
Machining Process ◽  
Machining Processes ◽  
Machining Time ◽  
Machining Strategy ◽  
Removal Processes

In material removal processes, determination of optimal machining strategy is a key factor to increase productivity. This situation is gaining more importance when machining components with complex geometry. The current practice in the determination of machining strategy mostly depends on the experience of the machine operator. However, poorly designed machining processes lead to time-consuming and costly solutions. Therefore, the improvement of machining processes plays a vital role in terms of machining costs. In this study, the machining process of a boom-body connector (GGG40) of a backhoe loader was improved. Improvements of toolpaths and cutting conditions of 22 different material removal processes were checked through a CAM software. According to the simulation results, the process plan was rearranged. Besides, some enhancements in casting model were conducted to decrease in the number of machining operations. When compared to current practice, a reduction of 55% in machining time was achieved.

Machining

2013 ◽  
pp. 213-270
Keyword(s):  
Electron Beam ◽  
Tool Wear ◽  
Electrical Discharge ◽  
Cutting Fluids ◽  
Machining Parameters ◽  
Machining Processes ◽  
Wire Cutting ◽  
Grinding Operations ◽  
Conventional Machining

Abstract This chapter covers the practical aspects of machining, particularly for turning, milling, drilling, and grinding operations. It begins with a discussion on machinability and its impact on quality and cost. It then describes the dimensional and surface finish tolerances that can be achieved through conventional machining methods, the mechanics of chip formation, the factors that affect tool wear, the selection and use of cutting fluids, and the determination of machining parameters based on force and power requirements. It also includes information on nontraditional machining processes such as electrical discharge, abrasive jet, and hydrodynamic machining, laser and electron beam machining, ultrasonic impact grinding, and electrical discharge wire cutting.

scholarly journals Experimental Study on the Influence of Machining Conditions on the Quality of Electrical Discharge Machined Surfaces of aluminum alloy Al5052

Machines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 12 ◽  
Author(s):  
Angelos P. Markopoulos ◽  
Emmanouil-Lazaros Papazoglou ◽  
Panagiotis Karmiris-Obratański
Keyword(s):  
Aluminum Alloy ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
White Layer ◽  
Machining Parameters ◽  
Machining Processes ◽  
Machining Conditions ◽  
Pulse On Time ◽  
Machined Surfaces

Although electrical discharge machining (EDM) is one of the first established non-conventional machining processes, it still finds many applications in the modern industry, due to its capability of machining any electrical conductive material in complex geometries with high dimensional accuracy. The current study presents an experimental investigation of ED machining aluminum alloy Al5052. A full-scale experimental work was carried out, with the pulse current and pulse-on time being the varying machining parameters. The polishing and etching of the perpendicular plane of the machined surfaces was followed by observations and measurements in optical microscope. The material removal rate (MRR), the surface roughness (SR), the average white layer thickness (AWLT), and the heat affected zone (HAZ) micro-hardness were calculated. Through znalysis of variance (ANOVA), conclusions were drawn about the influence of machining conditions on the EDM performances. Finally, semi empirical correlations of MRR and AWLT with the machining parameters were calculated and proposed.

scholarly journals On the Determination of Meshed Distribution Networks Operational Points after Reinforcement

2019 ◽  
Vol 9 (17) ◽  
pp. 3501 ◽  
Author(s):  
Vasiliki Vita ◽  
Stavros Lazarou ◽  
Christos A. Christodoulou ◽  
George Seritan
Keyword(s):  
Monte Carlo Simulation ◽  
Distributed Generation ◽  
Electric Vehicles ◽  
Maximum Load ◽  
Distribution Networks ◽  
Network Robustness ◽  
Current Load ◽  
Objective Functions ◽  
Calculation Algorithm

This paper proposes a calculation algorithm that creates operational points and evaluates the performance of distribution lines after reinforcement. The operational points of the line are probabilistically determined using Monte Carlo simulation for several objective functions for a given line. It is assumed that minimum voltage at all nodes has to be balanced to the maximum load served under variable distributed generation production, and to the energy produced from the intermittent renewables. The calculated maximum load, which is higher than the current load, is expected to cover the expected needs for electric vehicles charging. Following the proposed operational patterns, it is possible to have always maximum line capacity. This method is able to offer several benefits. It facilitates of network planning and the estimation of network robustness. It can be used as a tool for network planners, operators and large users. It applies to any type of network including radial and meshed.

Sign in / Sign up

Export Citation Format

Share Document