Journal of Advanced Manufacturing Systems

Undercut feature recognition in automatic mold design requires analyzing the visibility/accessibility of the part along a known parting direction, the existing approaches for which are mostly restricted to polyhedral parts or a particular CAD platform or cannot handle partially accessible faces very well. The present work proposes a projection-based methodology to analyze the visibility of a part from a given parting direction without discretizing the part. An approach to further extract undercut features and generate corresponding side-cores is also presented. The implemented system uses STEP AP214/AP203 part files for input and output and has been successfully validated using parts geometrically similar to those used in literature as well as on a number of industrial parts of greater complexity.

This paper presents a comparative study of three micro-thermal actuators, which differ in their construction and material being used. Model-I is the basic model and Model-II and Model-III are developed with a view to achieve improved performance over Model-I. The main objective of this analysis is to achieve greater deflection from the considered actuator models under a range of applied voltages. Apart from deflection analysis, analyses for temperature distribution and stress developed in the actuator models are also carried out for feasibility study. The materials under consideration are poly-silicon, single crystal silicon, and titanium. The software used for modeling and simulation is Comsol Multiphysics.

Evolution is "understanding and overcoming current constraints in small steps toward optimum." "Understanding" requires elucidation of facts and corroborating theories that can explain those facts in a coherent manner. "Overcoming" requires self-development to suit the environment. In this paper, a case study about how a manufacturing process is improved in terms of productivity and quality using evolutionary improvements is explained. Here "Understanding" is achieved through use of Shainin Technique, PM analysis, Affinity Diagram, and the engineer's ingenuity, along with Relations diagram. "Overcoming" is achieved through Geometrical Analysis and Designed Experiments. The Study has set a new benchmark in the Stator riveting process by proving it can yield the desired results, and the need to adapt welding process is avoided.

In this paper, a genetic and heuristic approach is proposed for nesting of multiple, two-dimensional (2D)-shaped parts in 2D-shaped sheet with the aim of minimizing the wastage of sheet material. It presents a new method that can represent the geometry of sheet and part in a fast and effective way using the concepts of analytical geometry and semi-discrete form of representation. The method proposed to obtain an optimal sequence of parts is a modified genetic algorithm that chooses pre-determined sequence of parts as initial population instead of randomly generated sequence of parts as initial population. The effect of initial population on final optimal sequence and the effectiveness of the proposed scheme of representation are examined by comparing the results obtained to those obtained with the approach proposed by Babu and Babu (2001). Both utilized semi-discrete representation scheme proposed by Ma and Liu (2007).

This paper aims at automatic generation of optimal sequence of machining operations in setup planning by Genetic Algorithm (GA) based on minimizing the number of setup changes and tool changes, subject to various machining precedence constraints. The GA has been reconstructed as the method of representing an operation is not as simple as assigning it a binary digit as in case of a chromosome in traditional GA but it has to be a distinct real number. Accordingly, the GA operators had to be modified. At the end of each GA cycle, there might be chromosomes having high fitness values but not conforming to constraints. Moreover, due to randomness of GA, the conformable chromosomes might tend to get lost. In order to minimize such losses, the elitist model is used for selection of chromosomes. Furthermore, a special subroutine has been developed to check the chromosomes for conformability and modify/repair those that violate the constraints.