Xuan-Phuong Dang

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).

Development of a retention mechanism for minimizing defective overlap in film-insert molding

Film-insert injection molding is a relative new technique replacing for traditional post-molding decoration in order to cut down manufacturing cost and to avoid environmental pollution. In film insert molding, one of the most important considerations is how the inserted film is held in place in the mold tool for avoiding overlap phenomena. This paper presents a simple and effective mechanism that holds the inserted films in desired places during the injection process. The mechanism consists of adaptive retention pins with special designed shapes and appropriate spring force. The proposed method was applied to the chrome-plated film-insert molding process for an automotive radiator grill. The result shows that the defective rate caused by overlap phenomena reduces from about 20% to 3% when changing from electrostatic holding method to the new proposed design. The manufacturing cost of the radiator grill made by film injection molding method reduces 7.8 % compared to the one made by a traditional chrome-plating method.