Hong-Seok Park

Structural optimization based on CAD-CAE integration and metamodeling techniques

Traditional structural optimization, which identifies the best combination of geometrical parameters to improve the products performance and to save the material, is often carried out manually. This paper presents a framework that performs the integration between commercial CAD-CAE software by using common scripting, programming languages and Application Programming Interface. The loop of design-analysis-redesign in optimization process was done automatically and seamlessly without interaction with designer. Along with CAD-CAE computer-aided tools, metamodeling techniques including response surface methodology and radial basis function were applied to structural optimization according to the number of design variables. This approach reduces the time for solving computation-intensive design optimization problems and the designers are free from monotonous repetitive tasks. Three case studies were carried out in order to verify the feasibility and general-purpose characteristics of the proposed method for the structural optimization process of mechanical components. The results show that the proposed method facilitates the structural optimization process and reduces the computing cost compared to other approaches.

Design and Simulation-Based Optimization of Cooling Channels for Plastic Injection Mold

Injection molding has been the most popular method for making plastic products due to high efficiency and manufacturability. The injection molding process includes three significant stages: filling and packing stage, cooling stage, and ejection stage. Among these stages, cooling stage is very important one because it mainly affects the productivity and molding quality. Normally, 70%~80% of the molding cycle is taken up by cooling stage. An appropriate cooling channels design can considerably reduce the cooling time and increase the productivity of the injection molding process. On the other hand, an efficient cooling system which achieves a uniform temperature distribution can minimize the undesired defects that influence the quality of molded part such as hot spots, sink marks, differential shrinkage, thermal residual stress, and warpage (Chen et al., 2000; Wang & Young, 2005).

Augmented Reality based Cockpit Module Assembly System

Because of global competition, most of automobile manufacturer try to reduce the cost and time for the implementation of manufacturing system. The AR technology as a new man-machine interface introduces a noteworthy perspective for a new manufacturing system. Because virtual objects are superimposed to real scene, system planner can design and validate the new system without modeling the surrounding environment of production domain during short process planning time. In this paper, the architecture of AR browser is introduced and the optimal environment parameters for practical application of AR system are determined through lots of tests. Moreover, many methods such as multi-marker coordinate system, partition of virtual objects and so on, are proposed in order to solve the problems suggested from the initial practical test. Based on these tests and results, the test bed of a cockpit module assembly system is configured and operation program for cockpit module assembly is generated using the AR system.

Development for automatic control system

Agile and flexible manufacturing systems make it mandatory that control programs have features such as agility, flexibility and reusability to meet fast changing, customer demands. To cope with this, a task-oriented model of the control system provides control code, data mapping and generating PLC code according to assembly sequences. The model is defined with the unit functions which can describe the complex assembly process with function elements. Task-oriented model also means the assigning and combining of unit function to generate the PLC code for assembly process. The artificial intelligence method executes knowledge processing for generating the PLC program. This approach of task-oriented method supports the flexible programming with high level of reusability, expandability, modifiability, and productivity.

Autonomy for Smart Manufacturing

Smart manufacturing (SM) considered as a new trend of modern manufacturing helps to meet objectives associated with the productivity, quality, cost and competiveness. It is characterized by decentralized, distributed, networked compositions of autonomous systems. The model of SM is inherited from the organization of the living systems in biology and nature such as ant colony, school of fish, bee’s foraging behaviors, and so on. In which, the resources of the manufacturing system are considered as biological organisms, which are autonomous entities so that the manufacturing system has the advanced characteristics inspired from biology such as selfadaptation, self-diagnosis, and self-healing. To prove this concept, a cloud machining system is considered as research object in which internet of things and cloud computing are used to integrate, organize and allocate the machining resources. Artificial life tools are used for cooperation among autonomous elements in the cloud machining system.

Collaborative Engineering System Supporting Product Development Process

Since customer’s demand is various and product life cycle is getting shorter, many manufacturing company is trying to reduce product development time and cost. The processes of product development involve a large number of components and the interaction of multiple technologies. For the above reasons, companies make an effort to design product on collaborative environment. The various activities in a product development are highly distributed. This distributed nature of the activities implies that teams will be working in different place and technical environment. Thus at a given time, teams might work on the same product from different perspectives. This will require efficient communication amongst the various individuals and the various software tools that are used by them. Therefore, there is a need for collaborative system that can support distributed design such that participants from different background collaborate towards one common goal. IT (Information Technology) is the foundation for collaborative system. In this paper the development of an enterprise-specific collaboration-strategy including process oriented co-operations in product development will be presented. This strategy particularly comprises new customer-oriented functionalities, tools for supporting collaborative product development as well as a systematic support for an implementation of collaborative system.Copyright

Design For Assembly: An approach to increase Design Efficiency of Electronics Home Appliance

Innovations lead market. In todays computational and technocrat world, product development needs a prompt respond to accomplish market demands in short time and must be economically sustainable. Since the product design strongly affects the assembly process, it must be taken care at the initial stage which results in improving manufacturing process, saving assembly time and thereby cost. In this paper, an active approach to reduce the number of parts and thereby increasing design efficiency has been taken into consideration. Design for assembly (DFA) approach was applied to facilitate product structure without losing its standardization and functionality of product. Comparative analysis between, current and proposed design of refrigerator components like evaporator fan in freezing compartment and door hinge assembly are described out of the many sub assembly part reduction in total number of parts of refrigerator. Using DFA guidelines, we reduced total number of parts from 328 to 172, thereby leading to increase in design efficiency by more than 25%. The results obtained from the analysis leads to achieve our required expectations and can be further applied in manufacturing industries in order to improve the design efficiency.

Finite Element Analysis of roll forming process of aluminum automotive component

Roll forming process is currently used in manufacturing of many automotive components. The material of roll formed product is gradually changed from proper steel to aluminum for reducing the weight of car. The process with aluminum material has many different characteristic to steel and still is not investigated clearly. This paper presents the Finite Element Analysis of roll forming of aluminum automotive component. Many important results, such as distribution of longitudinal strain, analysis of spring back phenomenon, failure in process, or redundant deformation have been obtained. The comparison between process with aluminum and steel is carried out. These results are necessary for determining major factors in optimization procedure of roll forming of automotive component.

Development of Smart Machining System for Optimizing Feedrates to Minimize Machining Time

Abstract Feedrate optimization is an important aspect of getting shorter machining time and increase the potential of efficient machining. This paper presents an autonomous machining system and optimization strategies to predict and improve the performance of milling operations. The machining process was simulated and analyzed in virtual machining framework to extract cutter-workpiece engagement conditions. Cutting force along the cutting segmentation is evaluated based on the laws of mechanics of milling. In simulation, constraint-based optimization scheme was used to maximize the cutting force by calculating acceptable feedrate levels as the optimizing strategy. The intelligent algorithm was integrated into autonomous machining system to modify NC program to accommodate these new feedrates values. The experiment using optimized NC file which generates by our smart machining system were conducted. The result showed autonomous machining system, was effectively reduced 26%.

Doping effect of copper ion (Cu2+) on the conductivity behaviour of ceria (Ce1−xCuxO1−δ) electrolyte

The doping effect of Cu2+ in a ceria matrix has been studied using a microwave assisted synthesis technique. Differential thermal and thermogravimetric analyses (DTA–TG) have been performed to understand the thermal response of Cu2+ doped ceria compositions. Structural and bonding changes in the doped ceria have been analyzed using XRD and FT-IR techniques, respectively. Impedance spectroscopy was performed on silver (Ag) coated pellets, sintered at 1100 °C for 2 hours. The obtained spectra in the temperature range of 300–500 °C and frequency region 1 Hz–1 MHz have been studied, and conductivity behavior has been discussed.