scholarly journals E-Textile Systems Reliability Assessment—A Miniaturized Accelerometer Used to Investigate Damage during Their Washing

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 605
Author(s):  
Shahood uz Zaman ◽  
Xuyuan Tao ◽  
Cédric Cochrane ◽  
Vladan Koncar

E-textiles reveal a new and hybrid sector of the industry that is created by the integration of electronic components or textile-based electronics in our daily life textile products. They are facing problems in terms of washability, reliability, and user acceptance. This manuscript explains the mechanical stresses acting during the washing process and their impact on e-textile systems. Different washing programs were investigated in terms of total process duration. This washing process duration is mainly divided into three diverse washing actions: low-speed rotation, high-speed rotation, and stop time. This investigation was performed to highlight the importance of the washing actions and their percentages in the total washing process. A piece of fabric with a flexible PCB (printed circuit board), equipped with an accelerometer with a Bluetooth communication device and a microcontroller, was placed in the washing machine to analyze the movement of fabric provoked by washing stresses. The PCB was used for fabric movements recording to determine the impact of mechanical stress on e-textile systems during the washing process. From the video analysis, it was concluded that the duration of the low-speed and high-speed rotation actions should be privileged comparing to the duration of the whole washing process. A power spectral density (PSD) analysis based on the accelerometer outputs was realized. Mechanical stresses at different frequencies were identified. Based on this analysis, it could be possible to improve the protocols of mechanical tests (Martindale and pilling box) used to simulate the mechanical stress applied to e-textile systems during the washing process.

Author(s):  
Yuefa Zhou ◽  
Tao Li ◽  
Zhiyuan Liu ◽  
Kexin Zheng

Abstract In the ocean environment, the ship is prone to motions in six directions of roll, pitch, yaw, sway, surge, and heave under the influence of the waves. It will affect not only the airworthiness of the ship, but also have an adverse impact for the crew and the board’s equipment. In view of this situation, a new type of ship anti-rolling device has been proposed, which is based on the structural characteristics of the Stewart platform with precise adjustment of the position of the load platform and the stability of the gyroscope under the high-speed rotation of the rotor. Firstly, theoretical analysis of the device conducted with theorem of moment of momentum method shows that the device has practical feasibility and effectiveness. Then, a solid model has been established in Creo2.0 software, and the model has been imported into the dynamic analysis software MSC.ADAMS. Finally, using torque as the exciting force to simulate the impact of the wave, the dynamic simulation of the overall model has been analyzed. The simulation results show that such device has good anti-rolling performance under certain waves, indicating that the new anti-rolling device based on the Stewart platform and the three-axis gyroscope has effective reliability and practicability.


2018 ◽  
Vol 55 (7) ◽  
pp. 071202
Author(s):  
赵义鹏 Zhao Yipeng ◽  
李铁军 Li Tiejun ◽  
王宁 Wang Ning ◽  
王旭之 Wang Xuzhi ◽  
刘今越 Liu Jinyue ◽  
...  

2020 ◽  
Vol 82 (2) ◽  
Author(s):  
K. Jafri ◽  
Rizauddin Ramli ◽  
Abdul Hadi Azman

Geometrical dimensioning and tolerance (GD&T) are an important element of the industry that uses high-speed rotation. Poor geometrical tolerance (GT) to components will cause the rotor to become unbalanced. Unbalanced rotor and shaft misalignment are the two major sources of vibration in the rotating system. This paper compares geometrical characteristics (GCs) to investigate the effects of vibrations generated by different GCs. Only four GC shafts were compared, straightness, parallelism, cylindricity, and concentricity, referring to the GD&T standard as ASME Y14.5-2009. These four GCs were selected owing to their direct involvement in the rotating system. Specimens are constructed with parameters of the same dimensions, length, and GT values only differ from GCs. Specimens were measured using a digital gage to find the GT value near 3000 micron at 3 mm. The magnitude of the shaft vibration during rotation was recorded using a VA-12 vibration analyzer with different rotational speeds: 510, 770, and 900 rpm. From the vibration data, the GCs’ effect on the rotation shaft will be determined. GCs are found to have significant effects on the rotation of the shaft that should be considered in the design, installation, and maintenance of rotating shafts. The impact and degree of damage to critical parts of the system can serve as a benchmark for further studies for the optimization of tolerance values and for the maintenance of component performance.


1978 ◽  
Vol 21 (158) ◽  
pp. 1306-1310 ◽  
Author(s):  
Akio NAGAMATSU ◽  
Masaho FUKUDA

Author(s):  
Luca Bertocchi ◽  
Matteo Giacopini ◽  
Daniele Dini

In the present paper, the algorithm proposed by Giacopini et. al. [1], based on a mass-conserving formulation of the Reynolds equation using the concept of complementarity is suitably extended to include the effects of compressibility, piezoviscosity and shear-thinning on the lubricant properties. This improved algorithm is employed to analyse the performance of the lubricated small end and big end bearings of a connecting rod of a high performance motorbike engine. The application of the algorithm proposed to both the small end and the big end of a con-rod is challenging because of the different causes that sustain the hydrodynamic lubrication in the two cases. In the con-rod big end, the fluid film is mainly generated by the relative high speed rotation between the rod and the crankshaft. The relative speed between the two races forms a wedge of fluid that assures appropriate lubrication and avoids undesired direct contacts. On the contrary, at the con-rod small end the relative rotational speed is low and a complete rotation between the mating surfaces does not occurs since the con-rod only oscillates around its vertical axis. Thus, at every revolution of the crankshaft, there are two different moments in which the relative rotational speed between the con-rod and the piston pin is null. Therefore, the dominant effect in the lubrication is the squeeze caused by the high loads transmitted through the piston pin. In particular both combustion forces and inertial forces contribute to the squeeze effect. This work shows how the formulation developed by the authors is capable of predicting the performance of journal bearings in the unsteady regime, where cavitation and reformation occur several times. Moreover, the effects of the pressure and the shear rate on the density and on the viscosity of the lubricant are taken into account.


2012 ◽  
Vol 542-543 ◽  
pp. 828-832 ◽  
Author(s):  
Jing Fang Yang ◽  
Xian Ying Feng ◽  
Hong Jun Fu ◽  
Lian Fang Zhao

Tire dynamic balance detection plays an important part in tire quality detection area. This paper uses the two-sided balance method to obtain the unbalance of the tire. According to the engineering practice, builds kinetic model and then introduces the calculating principle and operating procedures. In order to accurately determine the influence coefficient, a calibration method without tire is put forward. Further more, this new method is able to eliminate the unbalance caused by non-quality factors to some extent. But this method is presented based on the relative position invariance of the upper rim and lower rim, even both of them are under high-speed rotation situation. Finally, the experimental data acquired from both of the two methods are compared. The calibration method without tire is proved to be more feasible, efficient and accurate.


2003 ◽  
Vol 439 ◽  
pp. 156-162
Author(s):  
A. Da Camara ◽  
Joaquín Lira-Olivares ◽  
Soo Wohn Lee ◽  
H.D. Park ◽  
Y.S. Park

1995 ◽  
Vol 251 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Kazumasa Muramoto ◽  
Ikuro Kawagishi ◽  
Seishi Kudo ◽  
Yukio Magariyama ◽  
Yasuo Imae ◽  
...  

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