A gap-type capacitive displacement transducer is adopted for measuring the elastic deformation of a tool-workpiece interface in cold simple upsetting. A 1-mm-diameter hole is bored straight to the depth of about 1.2 mm from the inside surface of a die and a steel pin is placed in the hole for detecting vertical displacements near the die-workpiece interface. The pin is pushed inward by a spring vertically. The vertical displacement of the die-workpiece interface pushes the detection pin outward. We measure the amount of deformation of the die from the variation of the gap between the head of the extruded pin and the head of the capacitive transducer. Gap-type capacitive displacement transducer has the advantage of high resolution, low noise, and excellent stability. We use 8 transducers in the experiment to measure displacement distribution simultaneously. This measurement system is applied to measure the die deformation in cold simple upsetting of pure aluminum billets. In conclusion, we demonstrate that this measurement method is useful for measuring die deformation in forging.

In this study, the vibration characteristics of an annular sandwich plate with a lattice core were investigated. The lattice cores were placed on Cartesian coordinates, and four different boundary conditions (fixed-fixed, free-free, fixed-supported, and fixed-free) were used for the outer and inner circumference of the disk. Six lattice cores of different geometries were also analyzed to compare the vibration behavior. In order to predict the natural frequencies of the circular plates, the sandwich plates were considered as equivalent homogeneous continuous plates, and the solution was obtained by using the Rayleigh-Ritz method. Also, finite element analysis (FE analysis) was performed to verify the accuracy of the obtained solution. As a result, it was confirmed that the natural frequencies of the low-order vibration modes agreed well with the present predictions regardless of the boundary conditions, provided that the dimension ratio of the model is within a certain range. On the other hand, as higher-order vibration modes and the difference between the outer and inner circumference of the circular plate become smaller, the error between the theoretical and numerical solutions by FE analysis becomes larger, which is due to the greater influence of shear deformation. Furthermore, a circular plate was modeled by a 3D printer and its natural frequencies were experimentally obtained.

In the engineering education field, 3DCAD has been widely adopted for a long time. With rapid advancements, software like SOLIDWORKS and Fusion360, which encompass CAE/CAM, are becoming increasingly convenient. However, balancing this with traditional hand-drawn drafting faces difficulties. Numerous pioneering educational approaches for CAE have been reported. The COVID-19 pandemic in early 2020 brought significant changes to daily life. In education, there's been a major shift from traditional face-to-face classes to online lessons to mitigate infection risks. In the CAD education field, many studies and initiatives have been undertaken. With the pandemic influencing educational formats, there's a surge in research on hybrid and online CAD education. At National Institute of Technology, Tokyo College (Tokyo Kosen), where the autohrs have worked, all students now own laptops and have installed CAD software, enabling them to attend classes from home or school. Some classes have actively adopted the flipped classroom method, allowing students to pre-study materials and engage in discussions during class. This not only enhances online class quality but also promotes self-study among students. This paper outlines CAE education at Tokyo Tech and discusses the author's efforts and challenges in online CAE instruction post-pandemic.

Honeycomb cores are well known and widely used in various fields including construction materials of aerospace structures, buildings, and transportation vehicles owing to their lightweight, high strength and high energy absorption capability. In this study, new bio-inspired honeycomb cores with square tubes were designed with different core sizes and fabricated using craft paper by corrugation method. We conducted quasi-static and dynamic out-of-plane compression tests on them. As a result of the experiments, it was found that the bio-inspired honeycomb cores with high core density exhibited higher strength than the conventional honeycomb cores even though the increase in mass of the bio-inspired honeycomb cores was taken into consideration. Also, fine buckling modes were observed locally around the square tubes and prevented continuous deformation of the cores so that the compressive load of the bio-inspired honeycomb cores remained higher than that of the conventional honeycomb cores during buckling deformation. Thus, the specific energy absorption of the bio-inspired honeycomb cores was improved compared to the conventional honeycomb cores except certain test conditions such as high impact speed and light drop weight.

Small ball bearings can be easily sealed with lubricant by using grease, so they are used in many applications such as bearings for home appliance motors. In addition, as performance requirements, there are increasing demands for higher efficiency and higher speed in electrical motors. To realize higher efficiency in motors, lower torque is required when applied to rolling bearings. Therefore, lower torque in bearings is an increasing demand. However, research on the torque of small ball bearings with grease lubrication has just begun, and it is difficult to say that the problem has been fully understood. Thus, in this study, the authors conducted a lot of torque measurement under the same rotation conditions using a commercially available grease-lubricated deep groove ball bearing 608. This is to investigate the current state of grease-lubricated torque in the bearing. As a result, it became clear that even products from the same bearing manufacturer do not have constant torque, and that there are large variations and fluctuations.

Catheter-based endovascular cerebrovascular therapy is a less physically demanding treatment for patients. In this treatment, a catheter is used to deliver a therapeutic device to the diseased area. X-rays are used to capture images of the device and blood vessels. Therefore, this treatment has the problem of cumulative radiation exposure to the surgeon and staff. A teleoperated robot has been proposed as a solution to this problem. Because cerebral blood vessels are thin and easily torn, the teleoperated robot needs a sensor to measure the insertion force of the treatment device. We have been developing the sensor, the detection accuracy of which was 0.02N in our previous study. The proposed sensor has an improved internal structure and improved detection accuracy to 0.01N. In addition, the practicality of this sensor has been further improved. This paper describes the structure and features of this insertion force sensor, accuracy measurements, and experimental results using a blood vessel model.