Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

<p>This research concerns sound transmission characteristic analysis for human middle ear lesions using finite element method. A large number of patients are suffering from the middle ear lesions, such as the tympanic membrane perforation, the arthrosclerosis, and the tympanosclerosis. These lesions can change the dynamic properties of middle ear, cause various kinds of hearing problems, as well as the decline of the quality of life. For an early detection of illness and the improvement of the cure, it is important to clarify the influence on hearing ability at the time of lesion of the middle ear. However, it is difficult to grasp the dynamic properties of the auditory organ of a human body by an experiment. In this paper, the dynamic analysis of the middle ear at the time of lesions using the finite element method was conducted. Firstly, a finite element model of a healthy middle ear was built up, and used to verify the validity of the model. The analysis results showed good correspondence to the experiment results of other study. Secondly, the influences of tympanic membrane perforations with different size and position are investigated. The analysis results showed that the decrease of hearing ability is proportional to the size of the tympanic membrane perforation. Especially, the perforation at lower part showed an obvious decrease of hearing ability. Thirdly, the influences of arthrosclerosis and tympanosclerosist occurring at different positions are investigated. The results showed that the arthrosclerosis of incudostapedial joint and the tympanosclerosist at upper part of the TM can obviously decrease the hearing ability.</p>

DOI： 10.1299/jsmedmc.2020.402

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：VSP BV  

In the fabric shaping process during resin transfer molding, fabrics are deformed due to inter-fiber sliding and buckling of yarns. We have observed inter-fiber sliding and yarn buckling in the deep drawing of fabrics by a cylindrical punch. The amount of punch traveling and the molding die radius affect the occurrence of inter-fiber sliding and yarn buckling. Comparing simulation results and actual deformation of fabrics, we should take account of inter-fiber-sliding and buckling of yarns.

DOI： 10.1163/156855103322320356

Web of Science

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：高知  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：高知  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：高知  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Akita  

DOI： 10.1299/jsmemecj.2019.J10101P

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Fukuoka  

This research concerns high efficiency propulsion method of multi-articulated robot by decentralized control using local feedback control. Recently, various robots which are useful when disasters happened have been studied. At the time of disaster, these robots need to promote with high efficiency. To answer this demand, the propulsion method using resonance was proposed. On the other hand, natural frequencies of propulsion robot are varying in synchronization with the change of external environment. In this paper, the control method of propulsion robot which drives at the resonance point automatically is proposed. Especially, investigation of the proposed method for large degree of freedom robot is done. Firstly, vibration propulsion mechanism is introduced. This device promotes using the difference of friction coefficient between moving forward and moving backward. It is easy to measure natural frequencies of the device without the difference of friction coefficient. Secondly, the design method controller of decentralized control is shown. The proposed decentralized control uses the local feedback control. The driving method using local feedback control can oscillate natural vibration of vibration propulsion mechanism by self-excited vibration. The decentralized control realizes the synchronization of the actuators through natural vibration mode by the force entrainment of the self-excited oscillator. The propulsion experiment by centralized control and decentralized control is examined to evaluate propulsion efficiency. As the result, the propulsion method by decentralized control is high efficiency as compared with the method by centralized control.

DOI： 10.1299/jsmedmc.2019.136

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡  

Language：Japanese  

Saint-Venant's principle is generally interpreted as the rapid decay of end effects, but we know some systems where the local stress decays slowly. The whole stress field of an elastic body can be expressed as superposition of stress fields, which corresp

Language：Japanese  

Language：Japanese  

The authors developed the finite element method (FEM) for micropolar elastic solids and applied it to the problem of topology optimization. The weighted residual method and 8-node isoparameteric elements were employed for the FEM analysis. The solid isotropic material with penalization (SIMP) method and the gravity control function were employed in the optimization procedure. To test the numerical solutions, the bending problem of the cantilever was used. In this analysis, the effects of the engineering material constants for micropolar elasticity, the coupling number N, which is related to stresses, and the characteristic length 1, which is related to couple stresses, are researched. The optimal structures of micropolar materials are strongly influenced by material properties of bending. Though the optimal topologies of classical elastic solids are truss frames, in general, those of micropolar materials are rigid frames. Since the checkerboard structures are more apt to appear in the optimization process for micropolar solids than in classical elasticity, filtering (the gravity control function employed in this paper) or other techniques are required to obtain practical solutions. The proposed method could potentially solve the optimization problems of biomaterials such as bone tissue.

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：Japanese  

The impact phenomena between golf clubs and golf balls are studied in order to examine the possibility of the shape optimization of clubs. The release velocity and side spin of the ball after impact with golf clubs, whose shapes are arbitrarily changed, are evaluated through FEM simulations. The following results are obtained from some simulations. First, the shape of the club is greatly related to the performance of the release velocity and side spin of the ball as well as the sweet area of clubs. Therefore, effectiveness of the shape optimization of the clubs is confirmed. Secondly, the kind of the club shapes having good performance is clarified from the viewpoint of mechanical energy.