Journal of Advanced Manufacturing Systems

The present work aims to develop a genetic algorithm-based approach to solve the scheduling optimization problem in the Job Shop manufacturing environment. A new encoding scheme for chromosome representation has been developed for this purpose that denotes a priority sequence of operations, from which a schedule can be generated if the precedence constraints are known. The successful implementation of the proposed encoding scheme has been presented and its performance has been compared with the existing operation-based scheme found in literatures across different test cases by varying the number of jobs and machines in the shop floor.

Fused deposition modeling (FDM) is a process by which functional parts can be produced rapidly through deposition of fused layers of material according to a numerically defined cross-sectional geometry. Literature suggests that process parameters largely influence on quality characteristics of rapid prototyping (RP) parts. A functional part is subjected to different loading conditions in actual practice. Therefore, process parameters need to be determined in such a way that they collectively optimize more than one response simultaneously. To address this issue, effect of important process parameters viz., layer thickness, orientation, raster angle, raster width, and air gap have been studied. The responses considered in this study are mechanical property of FDM produced parts such as tensile, bending and impact strength. The multiple responses are converted into a single response using principal component analysis (PCA) so that influence of correlation among the responses can be eliminated. Resulting single response is nothing but the weighted sum of three principal components that explain almost hundred percent of variation. The experiments have been conducted in accordance with Taguchi's orthogonal array to reduce the experimental runs. The results indicate that all the factors such as layer thickness, orientation, raster angle, raster width and air gap and interaction between layer thickness and orientation significantly influence the response. Optimum parameter settings have been identified to simultaneously optimize three responses. The mechanism of failure is explained with the help of SEM micrographs.

CNC machines have become popular in the manufacturing sector in the last three decades. It is still expensive to afford all aspects related to the operations of these machines. One important aspect is the programming stage, which requires a skilful programmer and an appropriate programming media. Hiring a good programmer is not the cheap and the best solution, while having a commercial programming media is also not affordable for SME in Indonesia. This research is focusing on the design and development of a program checker to see whether the program for a CNC turning machine is correct and ready to be fed to the machine. At once, this program is also capable of displaying cutting simulation of how the product is to be cut in the machine. Therefore, this program will help a small manufacturing company to avoid hiring an expensive expert or buying special programming media. This program is specifically developed for a CNC Okuma Howa ACT 3 turning machine. Some results show that the program can easily point out error location if there is a logical or syntax error in the NC program. Moreover, the simulation can be executed only if all errors have been corrected. This feature ensures that the simulation can run properly. To run the simulation, one has to set up some variables such as workpiece dimension, tool position with respect to the machine, and cutter dimension.

Assembly sequence planning of a product involves several steps, including generation of precedence constraints, generation of assembly sequences, and selection of assembly sequences. Generation and selection of assembly sequences should be able to guarantee the feasibility of assembly. Assembly will be feasible if there is no collision between components when assembled. Detection of collision-free path of assembly can be done in an automated way. There are a number of collision detection methods that have been developed, but the method requires a complicated process of data geometry analysis. This paper proposes a method for detecting a collision-free path of the assembly component in a more simple way. Geometrical data required, taken from the three-dimensional (3D) solid drawing in the form of stacked drawing in computer-aided design (CAD) systems. Retrieval of geometrical data of components and detection of the collision-free path of an assembly were done in an automated way, directly from the CAD system.

In the automotive industry, sealing quality between two flat joint surfaces is directly affected by the surface flatness. To know how much flatness is caused by machining operations, a traditional trial-and-error method has been used. The prediction for machined surface error/distortion can help to assess the integrity of the structural design as well as develop fixturing scheme to optimize machining quality. In this paper, a finite element method is applied to extract the compliance matrix of milling surface of a workpiece, such as the cylinder deck face, and an encoding MatLab program is used to compute the flatness due to milling forces. The paper focuses on deriving analytical models for evaluating the flatness of the cylinder deck face and optimizing the manufacturing process. Some special considerations have been taken to manufacturing cutting force evaluations according to analysis results of the deck face flatness. Emphasis is also placed on the optimization of machining parameters by iterations of flatness results so that minimization of surface deformations under machining loads can be achieved. The methodology introduced in the paper is the closed-loop iteration by combining structural finite element analysis (FEA) simulation, tooling kinematic simulation, and MatLab data modeling.

This paper presents a state-of-the-art review of high precision finishing of gears by electrochemical honing (ECH) process. It is an electrochemical (EC)-based hybrid machining process combining the faster material removal capability of electrochemical machining (ECM) process and controlled functional surface–generating capability of conventional honing in a single action. The precision finishing of gears by ECH is a productive, high-accuracy, long toollife gear finishing process. The present study contains a detailed description of the process principle, influencing parameters, process capabilities, equipment details, applications, advantages and limitations, and comprehensive literature review of past research work on the ECH of gears along with some guidelines for further research with an objective to revive the interest of the global research community to mature this process further.