著者

河越 正羽 水谷 義弘 轟 章 松崎 亮介 安岡 哲夫

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集A編 (ISSN:18848338)

巻号頁・発行日

vol.79, no.801, pp.555-562, 2013 (Released:2013-05-25)

参考文献数

27

被引用文献数

1 3

---

In this study, a new welding method which utilizes conductivity of CFRTP (Carbon Fiber Reinforced Thermo-Plastic) is proposed. Electrical current is applied through the CFRTP single-lap joints in thickness direction. Since resistance of joining surface is the highest in the current path, the joining surface is preferentially heated by Joule heating. In this study, spot welding and surface welding were conducted. By applying constant voltage of 5.0V or 10.3V, the joint-surfaces were heated above melting temperature Tm of the material and were welded. In order to evaluate lap-shear strength (LSS) of welded joints, tensile lap-shear strength tests were conducted. As a result, the tensile lap-shear true stress of spot welding is 31.0MPa and LSS of surface welding is 22.0MPa. These strengths were comparable to those that were welded by traditional resistance welding method. It is also found that LSS is changed with welding pressure of joint parts.

著者

轟 章 大浅田 樹 水谷 義弘 鈴木 良郎 上田 政人 松崎 亮介 平野 義鎭

出版者

一般社団法人 日本複合材料学会

雑誌

日本複合材料学会誌 (ISSN:03852563)

巻号頁・発行日

vol.45, no.4, pp.141-148, 2019-07-15 (Released:2020-07-29)

参考文献数

11

被引用文献数

1

---

Continuous carbon fiber composites can be printed with 3D printers. Many studies detailing elucidations of the mechanical properties of such 3D printed composites have been published, all of which employed a conventional tensile specimen configuration with surface resin layers. In the present study, 0º, 90º, ±45º, and lay-up direction type specimens were newly designed for 3D printed composites without surface layers. Using the 3D printer, both conventional and newly designed specimens with serpentine folded fiber bundles were fabricated and investigated experimentally. The lay-up direction specimen was fabricated using 800 layers. The specimens without the serpentine folded fiber bundles were experimentally shown to be adequate for tensile tests. The lay-up direction specimen had the lowest strength and stiffness, which seems to be related to its surface roughness.

著者

島村 佳伸 麦島 新 轟 章

出版者

The Japan Society for Composite Materials

雑誌

日本複合材料学会誌 (ISSN:03852563)

巻号頁・発行日

vol.34, no.4, pp.133-140, 2008 (Released:2010-06-15)

参考文献数

15

被引用文献数

1

---

Moisture absorption affects mechanical properties of CFRP, thus monitoring of moisture absorption ration in CFRP is useful to assess the structural integrity. Besides, health monitoring of CFRP by using an electrical resistance change method has been investigated recently. In order to apply the electrical resistance change method to composite components in service, it is important to understand the effect of moisture absorption on the electrical resistance change. We have reported that the electrical impedance of CFRP increases not only in the transverse direction but also in the fiber. In order to investigate the effect of deformation constraint on the electrical impedance increase in the fiber direction, the electrical impedance changes of constrained and unconstrained CFRP specimens are measured at constant temperature and humidity. The results show that the electrical impedance change of the constrained specimen is much smaller than that of the unconstrained. The experimental results indicate that swelling in the transverse direction affects the electrical impedance in the fiber direction. The mechanism of electrical impedance change is discussed by using finite element analysis. The analytical results show that discrete contacts between carbon fibers and electrodes cause the electrical impedance change.

著者

松崎 亮介 轟 章 島村 佳伸 小林 英男

出版者

一般社団法人日本機械学会

雑誌

日本機械学会関東支部総会講演会講演論文集

巻号頁・発行日

vol.2004, no.10, pp.205-206, 2004-03-03

---

Safety of automobiles is increasingly demanded. To prevent burst of tires, smart tires are currently under development The embedded sensor enables highly precise measurement of road surface friction, and the precise friction measurements make more efficient anti-blocking-system (ABS). In a previous study, the authors proposed a new wireless strain monitoring method that adopts the tire itself as a sensor, with an oscillator circuit. This method is very simple and useful, but it requires a battery to activate the oscillator circuit. In the present study, the previous method for wireless tire monitoring is improved to produce a passive wireless sensor. The capacitance change of tire causes changes of the tuning frequency. This change of the tuned radio wave enables us to measure the applied strain of the specimen wirelessly, without any power supply from outside. This new passive wireless method is applied to a specimen and the static applied strain is measured.

著者

岩崎 篤 桑原 秀剛 轟 章 杉谷 恒也

出版者

一般社団法人日本機械学会

雑誌

日本機械学会関東支部総会講演会講演論文集

巻号頁・発行日

vol.2004, no.10, pp.207-208, 2004-03-03

---

This research is about a statistical diagnostic method for a structural health monitoring which is applicable to existing structures from the present moment. In this method, structural condition is statistically diagnosed by change of a response surface which is regression model of sensor's outputs. Change of response surface is statistically tested with F-test. In the F-test, a threshold value of normal/troubled condition is simply decided from a theoretical F-probability distribution. Therefore, this diagnostic method only requires data of intact condition and does not require the complicated modeling and information of troubled condition. To confirm the effectiveness of the presented method, health monitoring of jet fan is conducted. Load cells are mounted to a supporting system of the jet fan. Response surface is calculated from vibration data measured by the load cells. As a result, structural condition of the jet fan is successfully diagnosed with the method.