Hiroaki MORIMURA’s research while affiliated with Tokyo Institute of Technology and other places

In this paper, a new method to evaluate performance of sound insulating plates in closed medium is investigated by using acoustic finite element method (FEM) under such two conditions that plates are having free ends and that plates are simply supported. The proposed method is able to compute sound transmission loss by using sound pressures at the small numbers of properly selected nodes considering acoustical symmetry of modal shapes in the closed medium, which is equivalent to the theoretical transmission loss without using all nodes existing in the medium. By the proposed method, the computed transmission loss does not depend on sizes or shapes of the medium; it is the unique transmission loss of the sound insulating plate itself. As sound insulating plates, the following three models are constructed; a single plate, double-leaf plates and the high-rigid sandwich panel called “trusscore panel”. It is also shown that sandwich trusscore panel works effectively at low frequency range since it is sufficiently rigid and that computed sound transmission loss of the trusscore panel has tendency as observed on a single plate having the equivalent weight and stiffness to the trusscore panel. Trusscore panels can be applied widely in industrial fields in the future such as walls or floors in a car, train or building to reduce interior noise.

Nowadays the earth has been affected and polluted by various environmental problems, therefore reducing CO_2 emission for protecting environment, particular for emission of automobile has became an important issue. There are certain reports have confirmed that lightweight of vehicle had been able to contribute for reducing the CO_2 emission. So we direct our attention to Truss Core Panel as less weighty structure from the engineering application prospect of origami-engineering. The Truss Core Panel has better advantages in bending stiffness and in shear strength aspects. However, so far there are no studies of Truss Core Panel that apply the technology on the aspects of the shear stress and heat. In this study, we evaluate its shear and heat characteristics with Honeycomb Panel through the shear and heat simulation by utilizing multi-purpose analysis software of Nastran. And then we select design variable of Truss Core Panel to examine how the variable affects its shear and heat characteristics.

抄録 Packaging is essential to most kinds of industries. The basic part of the vertical form, fill and seal packaging machine is the forming collar. The forming collar provides the shape over which packaging film is smoothly formed into a cylindrical shape at high speed. Describing the forming collar geometry and hence its design is, however, remarkably difficult. And performance assessment for designing correct forming collar is not exited. This paper presents, for the first time, a method for the assessment by calculating the stress of the film on the geometry of the forming collar. Developable surface and non-developable surface are discriminated with this created method. Effect of mesh size of the finite element method for this analysis is analyzed. And accuracy of this method is confirmed to be put to practical usage.

Kansei design of comfortable and beautiful tableware for camping, traveling, and picnics is the interesting task. This tableware should be light, compact and convenient. In this paper, we suggest to use origami-based approach for designing this kinds of tableware. Cylindrical origami structure is used for creating the patterns for the tableware design. By changing the shape of bottom polygon and angles of folding lines, the different designs are created. Patterns for creating the different model shapes are constructed by applying software "ORIPA". For 3D simulation "Freeform Origami" software is used.

Now, many products are packaged, like foods, medicines, and other groceries. Products like snacks are packaged by package machines. Forming collar, which is a part of the package machine, is very useful to make machine space-saving design and increase in packaging speed. But the current design method has problems in productivity and reliability, because it is based on traditional experiences and trial and error. So we used finite element method to design collar shape. This method could calculate shapes which could minimize the strain energy. Therefore it is thought to be useful to design collar shapes which create few wrinkles. Then, we show the relation between wrinkles, scratches and bending when passing through the forming collar.

Packaging is essential to most kinds of industries. The basic part of the vertical form, fill and seal packaging machine is the forming collar. The forming collar provides the shape over which packaging film is smoothly formed into a cylindrical shape at high speed. Describing the forming collar geometry and hence its design is, however, remarkably difficult. And performance assessment for designing correct forming collar is not exited. This paper presents, for the first time, a method for the assessment by calculating the stress of the film on the geometry of the collar. Developable surface and non-developable surface are discriminated with this created method. And accuracy of this method is confirmed to be put to practical usage. Attention of this method is mesh size of the Finite Elements Method.

The basic part of the vertical form, fill and seal packaging machine is the forming collar. The forming collar provides the shape over which packaging film is smoothly formed at high speed into a cylindrical shape. Describing the forming collar geometry and hence its design is, however, remarkably difficult. This paper presents, for the first time, a flexible methodology for calculating the complete geometry of the film rather than the usually non-complete collar over which the film is formed. That is, a methodology to calculate the film geometry over the collar including the seam along which the film is longitudinally sealed. The film geometry is calculated such that it has minimum deformation energy. Advantages of the proposed methodology include its great flexibility to generate collars with different configurations for different needs. Among the collar generation methods reviewed, the proposed methodology is the first that can systematically consider all collar configuration parameters such as the seam configuration, general package cross-section, flat or straight part of the collar, collar back angle, etc. A means for obtaining the exact collar geometry is also demonstrated. This enables right-first-time and repeatable collar production and reduces the time and cost for producing next generation packaging machines. Copyright © 2010 John Wiley & Sons, Ltd.

Spacecraft inside a fairing experiences severe high-level random acoustic loads during its launch. To confirm that the spacecraft structures and equipment withstand the launch environment, ground acoustic test is performed in the process of design. Spacecraft is exposed to a diffuse sound field in a large reverberant room during ground acoustic test. On the other hand, spacecraft, especially that has a narrow clearance between spacecraft exterior panel and fairing wall, is exposed to the standing wave sound field, which is called 'Fill Effect', instde a fairing during launch. Fill effect has been identified for these few decades, but there have been few reports to discuss the vibration response of a spacecraft induced by the fill effect. In this paper, the simplified approach is proposed to compare the vibration response of a spacecraft induced by standing wave sound field with the one by diffuse sound field. This approach can be dedicated to the desigh of a spacecraft which may be exposed to severe fill effect. One analysis example of a plate structure under these two sound fields is shown.