A strut tower brace is one of the components that can improve the driving stability of a vehicle. This component has received steady attention for a long time due to its affordable price and easy installation. However, strut tower braces sold in the market have different structures. Moreover, most of them do not contain sufficient information related to safety or stability. Thus, this study aimed to analyze and compare structural behaviors of strut tower braces having various body shapes under bending and compressive scenarios. For this purpose, this study selected six representative models in the market and calculated structural behaviors (stress and deformation) using finite element analysis. Results revealed the body shape had a decisive effect not only on the durability of the strut tower brace, but also on the safety and stability of the vehicle. Among the six models tested, the model having a body shape with a single-axis form utilizing a wide rectangular cross-sectional showed the best bending and compressive performances. This study also confirmed that bending and compressive performances could be simultaneously improved depending on body shape.

With advancements in semiconductor manufacturing processes and the development of precision processing technology, flexure hinge-based ultra-precision positioning stages are widely used. In the flexure hinge, axial and bending stiffness properties greatly influence positioning performance. This study examined the stiffness properties of elliptic and parabolic 2-degrees-of-freedom (DOF) hinges, which have not been extensively discussed. The Timoshenko beam theory was applied to derive the stiffness equations for the axial and bending directions of each hinge. The stiffness properties were examined in several design conditions by comparing theoretical and finite element analyses. Based on the results of the analyses, an empirical formula in exponential form for the design of an elliptic hinge was constructed through surface-fitting. The elliptic hinge was found to be a better alternative to a circular hinge under certain design conditions by adjusting two design parameters. In the future, we will develop sophisticatedly designed hinges with improved axial and bending stiffness properties compared to the existing circular and elliptic hinges.

A theoretical and numerical FSI approach is used to predict the mass flow in a Coriolis flow meter. By comparing with the experimental results according to the relationship between mass flow and the time phase difference at the inlet and outlet of the tubes, the authors could determine the reliability of the present results from a theoretical and numerical approach in this paper. The mass flow has a linear relationship with the time phase difference, which is a unique parameter to measure true mass flow; therefore, for more precise measurement, it should be long enough to detect the signal within the given time resolution afforded by the detecting system and control system. Compact size and manufacturability, which are the important factors that decide the product competitiveness, should also be considered. In this paper, inversed triangle shaped and conventional U shaped Coriolis flow meters are designed, their time phase difference performances are predicted, and the results from experiments are well matched with the predicted results from the above-mentioned analysis.

Research on the application of additively manufactured polymer (AMP) to the conventional manufacturing process is underway. In this study, an additively manufactured die-set (AMDS) was used and applied to the warm forming of the magnesium alloy. Heat transfer and coupled temperature-displacement analysis were conducted in the V-Bending and UBending processes to study the applicability of the AMDS to the warm-forming process of the magnesium alloy sheet (AZ31B). A heat transfer experiment was conducted to determine the thermal contact conductance between the AZ31B material and two types of die-set, the metal and AMP. V-Bending and U-Bending experiments were conducted at 373 and 423 K; reduction in temperature between metal die-set and the additively manufactured polymer die-set were compared. The springback after the bending process with different initial temperatures and die materials was investigated. The simulation model showed good agreement. The springback of AZ31B was more decreased with the additively manufactured polymer die-set than with the metal die-set. The stress of the additively manufactured polymer die-set in the bending process was very small. It was confirmed that in the AZ31B material, the additively manufactured polymer die set helps increase the formability and decrease springback by keeping the temperature of AZ31B better.

Since earth pressure changes depend on soil depth and surrounding situations, the construction of earth retaining temporary structures should be able to measure the change of the earth pressure and cope with the changes. When the underground excavation and construction of earth retaining temporary structure repeatedly occur, the excavation should be less interfered by the earth retaining structure. A PS synchronize wale measures the horizontal deflection of the structure and generates tension on the wire rope by controlling the hydraulic cylinder so that the wale is in safe range. Since the horizontal load is canceled by pre-stress bending moment, the number of struts the horizontal load is reduced making the excavation interference is small. We evaluated the horizontal deflection of the PS synchronize wale with increasing tension and verified that the deflection of the PS synchronize wale can cancel out the horizontal load in the safety range of 5 mm. This occurs through a universal testing machine experiment simulating earth pressure. We are in the process of applying the PS synchronize wale to a test bed and expect it to be safer and more efficient than existing methods.

Laparoscopic surgical instruments have been used widely since 1980s and they are still important tool to the medical field as the surgical robot systems spread. In this study we devised three types of motorized mechanism to reduce the user hand fatigue. We detailed the mechanism of each type and compared the performances with several indices such as a bending angle, response time and number of mechanical components. And also we show the movement relationships among the jaw joint, passive gimbal set and motors in the case of MPDG (Motor Drive with a Push Disk and Driven Disk of Gimbal Mechanism) type during the typical jaw joint motions. MTPS (Modified Two Parallel Semicircle Guide Mechanism) type excels others in response time and number of components while showing the increase of load and kinematic occlusion during the diagonal movement. MBDG (Motor Drive with a Ball-Screw, Link and Disk Type Gimbal Mechanism) type shows the medium level bending performance with slow response time and large number of components. Lastly MPDG type excels in jaw joint bending performance with an unstable rotation motion transfer between pushing disk and driven disk at the large disk rotation angle.

Recently, the metal grid electrode drew attention as a flexible transparent conductive electrode for touch screen panels. In metal grid electrodes, various shapes of grid patterns were used to avoid the moiré phenomenon. In this study, we investigated the effects of the metal grid shapes - such as the honeycomb, diamond, and square - on the flexibility and durability of the metal grid film using an experimental and numerical analysis. The flexibility of the metal grid film was evaluated via the following: bending, cyclic bending fatigue and stretching tests; it was compared with the numerical stress analysis. In the bending test, the resistance of the honeycomb grid sample increased by 10% at a bending radius of 10 mm. On the other hand, the diamond grid showed almost no change in resistance up to a bending radius of 6 mm. When the substrate was stretched to 5%, many cracks appeared on the surface of the honeycomb pattern sample. On the other hand, no cracks were found in the diamond pattern sample. Therefore, the diamond pattern exhibited superior flexibility and durability to the honeycomb pattern. The numerical stress analysis also showed that the honeycomb pattern had the highest stress and the diamond pattern had the lowest stress during bending and stretching, which corresponded with the experimental results.

The applicability of flexible OLED devices has been expanding to rollable or foldable displays and lighting. At this time, a system to measure the durability of flexible OLEDs needs to be developed to successfully launch flexible OLEDs in future electronic devices. In this paper, we develop a bending lifetime tester to measure the performance of flexible OLEDs by measuring the luminance of the device in real-time during the bending test. A fixed distance between the bent OLEDs and detector during the bending test improves the accuracy of the measured brightness in real time. This bending tester can measure the lifetime of flexible OLEDs with a mean deviation of less than 0.23% over a temperature range of -30 to 80℃. This performance is sufficient to measure the accelerated lifetime test of flexible OLEDs for reliability engineering.

The flexural characteristics of corrugated sandwich panels are anisotropic and depend on its corrugation geometry and load position. The objective of this paper is to examine the influence of corrugation angle and load position on the flexural characteristics of plastic sandwich panels with trapezoidal corrugated cores subjected to ASTM three-point bending via finite element analysis. The stress distributions at mid span have been plotted to determine the stress concentration at different corrugation angle and load position. The specific flexural stiffness and modulus have been estimated from the loaddisplacement and stress-strain curves, respectively. The failure of the specimen due to stress or strain limit has been examined via maximum limit stroke. Results have shown that the specific flexural stiffness and modulus improve as the corrugation angle decreases. The load position has influenced the flexural characteristics due to the occurrence of local bending and local tension.