Tetsuo Oya

Method for evaluating mechanical characteristics of biological material for bio-inspired lightweight design

ABSTRACTWith increasing concern about cost reduction and environmental destruction, lightweight structural design is essential in the product design process. As a means of yielding products with more lightweight and efficient structures, in this paper a method of extracting useful features from a biological lightweight structure, that of the American lobster is proposed. Tensile tests were conducted on biological specimens using plastic clamps made by a 3D printer and clarified some rules for the design of lightweight and efficient structures. Using the rules of material design, a novel method for acquiring bio-inspired lightweight designs was proposed and its feasibility was shown by FEM simulation.

High-Quality Shape Fitting for Aesthetic Modeling Based on Class A Condition

ABSTRACTIn this paper, we propose a method of obtaining high-quality shapes from point clouds. We adopted the “Class A” concept, which has been defined as a shape that is monotonic in its curvature. Such high-quality shapes are preferred in product styling; therefore, an efficient method for their generation will be helpful in the style design process. The proposed method is based on a subdivision surface technique, the Class A definition, and a genetic algorithm. The proposed method is tested on some examples of surface generation, and the results demonstrate the effectiveness of our approach.

Robust Design on KANSEI of Product Satisfying Emotion and Preference of Target Customers Using Taguchi Method

It has been difficult to make product differentiations from standpoints on function and quality because each manufacturer has had the same level of manufacturing technologies. In order to provide attractive products for customers, it is essential to product emotional products satisfying a specified target level of KANSEI and preference of restricted customers. Taguchi method is effective for robust design of product functions but it is uncertain for design of product forms. In this paper, Taguchi method is applied for robust form design satisfying a specified KANSEI and preference of restricted customers by proposing and introducing the original S/N ratio. The effectiveness of the proposed form design method is verified by experiments based on questionnaires.Copyright

Framework for springback compensation based on mechanical factor evaluation

Springback is an inevitable phenomenon in sheet metal forming, and many researches on its prediction and compensation method have been presented. The use of high-strength steels is now popular; therefore, the demand for effective springback compensation system is increasing. In this study, a novel approach of springback compensation is presented. The proposed framework consists of a springback solver and design system and optimization process. The springback solver is a finite element procedure in which the degenerated shell element is used instead of the typical shell element. This allows the designer to access directly to the resultant stresses such as the bending moment that is a major cause of springback. By our system, mechanically reasonable springback compensation is possible whereas the conventional compensation method only uses geometrical information that may lead to non-realistic solution. The authors have developed a system based on the proposed procedure to demonstrate the effectiveness of the presented strategy and applied it to some forming situations. In this paper, the overview of our approach and the latest progress is reported.

Study on Method to Generate Wood Grain Pattern Representing Required Impression

Various approaches for generating wood grain patterns using computer graphics have been proposed so far. However, with such conventional methods, it is difficult to reproduce real wood grain patterns, as well as design wood grain patterns with impressions that reflect customer needs.This paper proposes a new approach for generating wood grain patterns. For instance, it can generate virtual trees by simulating tree growth taking into consideration environmental conditions, model fine tree tissues and reflection properties at the wood surface, etc. By applying these modeled factors, more diverse and accurate wood grain patterns can be generated. The authors also propose a method of controlling the grain patterns generated based on Kansei to realize grain patterns that meet customer needs. By building the basic system of the proposed method, various grain patterns could be generated, and grain pattern impressions controlled.Copyright

Low cost mixed reality system using projectors for evaluation of product design (shape and function structure)

Three-dimensional models (CAD models) are constructed in the design processes of products because they are effective for design evaluation processes using CAE systems and manufacturing processes using CAM systems. However, mock-ups or prototypes are still required in the evaluation processes of designability and operability of products because the evaluation of the operations of real products is essential. It is however time-consuming and costly to make prototypes or to develop trial products for evaluation. For this problem, considerable studies have been conducted on the use of mixed reality technology by overlaying an image of the design model onto a physical model using a Head-Mounted Display (HMD) to evaluate the designability and operability of a product. Such technology reduces the need for making physical mock-ups (prototypes and trial products), but HMDs have drawbacks such as causing motion sickness and physical weight, bulkiness of the display, and high costs. In this paper, a method using projectors is proposed to establish mixed reality technology which does not have the drawbacks of HMDs. A mixed reality system was constructed according to the proposed method, and applied for evaluating designability and operability of products without physical mock-ups. In the mixed reality space built by the system, the functions of a product can be held in the hand as if they were real products.Copyright

Style Design System Based on High-Quality Aesthetic Shapes to Support Designer’s Creative Activity

Class A shapes are used as an aesthetic standard mainly in automotive industry. Those used in products’ exterior are closely related to products’ values. Class A shapes have two geometric conditions: The surface has enough geometrical continuity, and smooth and continuous highlight lines. In our previous study, we developed a Class A curve generating method and style design system. Using this system, an user can create a model with several Class A curves. Then, we created a model by this system to evaluate the proposed method. Although we can create an aesthetic shape using this system, some shapes were not good in curvature variation. There is reason why some generated curves didn’t produce Class A shapes. In this study, we investigate more detailed conditions of Class A curve, and improve the Class A shape generating method using Class A curve. In our new method, we extend the range of Class A conditions. By this extension, Class A shape can be generated more efficiently than the previous method. Then, we create a model using this method in order to evaluate the surface quality, and discuss the effectiveness of our system.Copyright