The tendency of portable telephone and miniaturization of electronic equipment that it is supposed in book-size personal computer, etc., portable type is remarkable in recent years. The impact breakdown in the soldered joints division by the falling surfaces with it as a new problem. However, the elucidation of the effect of the whole package of the behavior on soldered joints divisions is insufficient to the destruction, and it is necessary to clarify the behavior, when the impact breakdown in the soldered joints division is evaluated. Then, it is necessary to clarify the behavior, when the impact breakdown in the soldered joints division in evaluated.

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The currently biomechanical trend seems to be that unless mechanics are applied at the cell or on the nano level, there is lack of originality, innovation, and depth in research. However, many things are still unknown or not fully understood, and therein lies the attraction of the biomechanical field. Theory of elasticity is as relevant to living organisms as to physiology and biosolid mechanics, and mechanical engineers are making contributions to the understanding of cell biology, physiology, as well as to the establishment of rehabilitation treatment and genetic engineering. In this paper, some research approaches to clinical and orthopaedic biomechanics in the musculoskeletal system were demonstrated in oreder to introduce the important and basic role of mechanics in the development of new medical techniques in near future.

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This paper presents the noise generation mechanisms for dry Hybrid type CVT(Continuously Variable Transmissions) at steady state. Tracking analyses were conducted to identify locations of noise sources by using a simple two pulleys belt system. The variation of noise characteristics with respect to the pulley rotational speed was measured. The frequency of noise generated in the CVT agrees with the number of contact of H-shaped blocks of the dry hybrid belt. This coincidence indicates that the noise with high frequencies like an impact sound is generated due to collision between CVT blocks and the pulley at both entrance and exit of the pulley groove. The influence of clearance between the tension member and the block was investigated on the sound pressure. It is considered that the clearance between the tension member and the block alters the contact condition between the block and the pulley. It also increases noise containing high frequencies.

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Form factor is an important inducement to explain a generating mechanism of warpage in injection molding product. Especially, fiber orientation state and shrinkage is affected by product form. Character of warpage deformation is determined by fiber orientation state that is caused by form factor in PBT-GF ribbed plate.

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The measurement accuracy of dynamic material testing is required for the development of design and numerical simulation based on the accurate model of stress-strain relation which is applicable to various strain-rate conditions. In this study, the size and geometry of specimen suitable for dynamic tension tests are evaluated by using finite-element method. At first, a basic cylindrical-shaped specimen with grip parts is examined, and then a plate specimen with the tab parts which are pulled by testing apparatus is modeled to evaluate the actual configuration of the non-coaxial Hopkinson bar method. The results obtained from those analyses show some requirements of specimen used for dynamic material testing concerning the aspect ratio of parallel part, the relation between its length and strain rate, and so forth.

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With a one-bar-method type dynamic tensile testing machine, dynamic behavior of Al alloy thin plate specimen was affected by the materials of the testing machine. An initial peak was appeared frequently on the stress-strain curve. Varying with the testing machine materials, that is, steels and Al alloys, the most reliable behavior of the specimen was obtained by the machine of all Al alloys, for 7075-T6 Al alloy specimen of 1mm in thickness.

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In this work, repeated impact test by glass beads of which diameter is 4mm were carried out for a silicon nitride plate. The impact angles of a glass bead against the silicon nitride plate surface were changed from 90 to 45 degrees. The plate specimen was fractured due to a corn type of crack propagation. The impact angle effect on the number of cycles to fracture was reasonably explained if the normal component of the impact velocity onto the specimen plate surface was considered. In addition, the two-point impact test was carried out to understand multi-site impact damage. The second impact points were sifted by 0.5mm, 1.0mm and 2.0mm from the first impact point. The first impact was continued until 150times and 200times. Then, the second impact was continued until the fracture took place in the specimen. When the second impact point was 0.5mm far from the first impact point. the number of the second impact repetition was apparently decreased as compared with the result of the virgin specimen. Those experimental results could reasonably be understood from the dynamic stress analysis results.

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The present study deals with impact fatigue of materials subjected to repeated stress due to impact loading. It has been pointed out by investigators that the behaviour of materials under the impact sterss is different from that under the static one. In this study, we observed the slip bands of the metal surface of specimen by optical microscope after test for a given repeated impact tension. The stress of specimen was measured by the two point gage method based on the stress wave propagation. As a result, we showed that the number of repetitions to fracture has a close relation with slip bands.

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The radiated sound from the impacted body must have the information with respect to the impact force. We have proposed the method in order to identify the impact force by analyzing the radiated sound from the impacted body. This sound is measured by the microphone and the impact force can be given by the inverse analysis using FFT. In this paper, the transform function between the impacted force and sound pressure will be obtained by the FEM simulation. Thus, the impact force can be obtained one time measurement of the impacted sound without any experiment for the calibration.

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