In this work, the crushing behavior of a combined honeycomb structure is studied based on the numerical results of finite element method analysis. It is found that the compressive process of the combined honeycomb, which consists of two honeycombs H-1 and H-2 arranged in different directions, can be divided into two steps corresponding to compression of the constituent honeycombs separately. As a result, the compressive load of the combined honeycomb can be predicted from the theoretical results for each honeycomb H-1 and H-2. Also, the scale of the impactor affects the amount of compressive load, and if the radius of the impactor is 7 times larger than the length l of the cell wall, the compressive load reaches the value for the case of impact by a rigid wall.

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This study is conducted to verify the technique of fatigue limit evaluation through numerical simulation. Temperature evolution of a notched stainless steel specimen subjected to cyclic loading is simulated by elasto-plastic finite element analysis. Both amplitude of second harmonic and mean temperature rise are obtained from the temperature evolution. It has been shown that the fatigue limits evaluated from the second harmonic amplitude and from the mean temperature rise agree fairly well with the fatigue limits obtained by thermography experiment and Wöhler method.

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To display information, flexible displays are a promising device. We present energy methods in conjunction with the calculus of variation to obtain deflections of flexible substrates subject to torque. In addition to analytical derivation, in experiments an electric motor under computer control exerts torque to generate display torsion, whose twist angles are obtained by using both optical encoder measurement and theoretical calculation. Comparisons are made between experimental and theoretical results for PET (polyethylene terephthalate) and PEN (polyethylene naphthalate) polymer substrates. Both experimental and theoretical results show that the required torque due to unit twist angle increases with the twist angle. A larger PET substrate is not as easy to be twisted as smaller one. In addition, a square PET substrate is not as easy to be twisted as rectangular one with the same width.

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Usually, automobile brake and power steering hoses have been developed through investigating several actual prototype hoses experimentally. Recently, high durability has been required for brake hose because periodic renewing has not been requested anymore for personal automobiles. In this study, FEM stress analysis has been applied to the crimped portion of hydraulic brake hose in order to promote developing the automobile hoses more efficiently. It is found that the large normal stress σ_n, which may control the sealing performance, appears at the crimped portion between the nipple and inner rubber. The results suggest that several grooves putting at the surface of nipple are effective for causing large σ_n, which may improve the sealing performance and hose lifetime. The effect of compression set of the rubber on the sealing performance is investigated, and the lifetime of hydraulic brake hose is estimated form the maximum stress appearing at the groove on the nipple.

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Clinching is a mechanical joint for fastening sheet metal components, and it is widely used in automotive industry. In this paper, the application of mechanical clinching to a built-up aluminum beam is studied. At first, tensile-shear tests and fatigue tests are carried out on clinched joints of 6063-T5 aluminum alloy sheet to investigate the tensile-shear strength and fatigue strength. Then, based on the joint strength results of clinched joint, the joint pitch of the built-up beam is designed under the specified bending load. Lastly, static bending test and cyclic bending test are carried out on the built-up beam to investigate the deformation behavior and the flexural rigidity. It is found that load-deflection relation and load-bending stress relation of the built-up beam are equal to those of one type beam calculated using Euler-Bernoulli beam theory. The built-up beam is proved to have the same flexural rigidity as that of one type beam. Cyclic bending test results show that cyclic loading gives no influence to clinched joints and the flexural rigidity of the built-up beam. All results demonstrate that mechanical clinching is an effective connection method in a built-up beam.

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In this paper, the effects of notch radius for different notched specimens have been studied on the values of stress concentration factor, notch strength reduction factor, and fatigue life duration of the specimens. The material which has been selected for this investigation is Al 2024-T3. Volumetric approach has been applied to obtain the values of the notch strength reduction factor and results have been compared with those obtained from the Neuber and Peterson methods. Load controlled fatigue tests of mentioned specimens have been conducted on the 250kN servo-hydraulic Zwick/Amsler fatigue testing machine with the frequency of 10Hz. The fatigue lives of the specimens have also been predicted based on the available smooth S-N curve of Al2024-T3 and also the amounts of the notch strength reduction factor which have been obtained from volumetric, Neuber and Peterson methods. The values of stress and strain around the notch roots are required to predict the fatigue life of notched specimens, so Ansys finite element code has been used, and non-linear analyses have been performed to obtain the stress and strain distributions around the notches. The plastic deformations of the material have been simulated using multi-linear kinematic hardening and cyclic stress-strain relation. The work here shows that the volumetric approach does a very good job for predicting the fatigue life of the notched specimens.

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