1,721,002 research outputs found
Comprehensive evaluation of CFRP laminates using NDT methods for aircraft applications
No full textThe evaluation of carbon fiber reinforced polymers (CFRP) laminates during and after the Mode I test was successfully conducted, integrating non-destructive testing of acoustic emission (AE) and ultrasound scanning. Two different specimens [+45°/-45°/0°]2S and [0°/+45°/-45°]2S were used to detect the effects of stacking sequences of the laminates. Results indicated that applying AE sensors to the specimens slightly affect to the laminate performance. Thus, the laminates are validated and showed that for [+45°/-45°/0°]2S laminates, the system can withstand load and increase the displacement at break more than twice of [0°/+45°/-45°]2S laminates. Moreover, the ultrasound scanning showed that the crack trace is visible. [+45°/-45°/0°]2S laminates have smaller crack around 24 mm compared to [0°/+45°/-45°]2S laminates with 30 mm. Image analysis revealed that after specimen are forced to open, the [+45°/-45°/0°]2S laminates can prevent long crack compared to [0°/+45°/-45°]2S laminates. The double cantilever beam (DCB) test, employing various stacking sequences, demonstrated excellent examination results using non-destructive testing. Theoretical calculations regarding residual thermal expansion due to different coefficients of thermal expansion also revealed a slight impact of varying manufacturing temperatures on the laminates. These findings offer valuable insights for detecting, predicting, and preventing specimen failures in aircraft and aerospace structures without resorting to destructive examinations, facilitating appropriate preventive maintenance
Metals and chemical compounds contaminants in diesel engine lubricant with B20 and B100 biofuels for long term operation
No full textImproved environmental stability, electrical and EMI shielding properties of vapor‐grown carbon fiber‐filled polyaniline‐based nanocomposite
No full textFailure Prediction and Surface Characterization of GFRP Laminates: A Study of Stepwise Loading
No full textThe present study explores the failure and surface characteristics of Glass Fiber-Reinforced Polymers (GFRP). Stepwise loading was applied in this study to understand the multi-static loading effect on the laminates before final failure. The loading was set three times to reach 10 kN with loading–unloading movement before final load until failure. The results showed that the angle of the GFRP UD laminates’ position significantly impacts the system’s failure. The results were analyzed using theoretical calculation experiment analysis, and then the failure sample was identified using ASTM D3039 standard failure. The laminates with 0° layer on edge ([0/90]S laminates) underwent preliminary failure before final failure. The mechanism of stepwise loading can be used to detect the effect of preliminary failure on the laminates. The [0/90]S laminates are subjected to stress concentration on the edge due to fiber alignment and discontinued fibers in the 0-degree direction. This fiber then fails due to debonding between the fiber and the matrix. The laminates’ strength showed that [90/0]S specimens have an average higher strength with 334.45 MPa than the [0/90]S laminates with 227.8 MPa. For surface roughness, the value of Ra increases more than six times in the 0° direction and three times in the 90° direction. Moreover, shore D hardness showed that the hardness was decreased from 85.6 SD then decreased to 70.4 SD for [0/90]S and 65.9 SD for [90/0]S. The matrix debonding, layer delamination and fiber breakage were reported as the failure mode behavior of the laminates
Delamination behavior and energy release rate evaluation of CFRP/SPCC hybrid laminates under ENF test: Corrected with residual thermal stresses
No full textMetrologi dalam industri manufaktur
No full textBuku Metrologi dalam Industri Manufaktur ini disusun untuk merangkum dan mendiskusikan ilmu metrologi dalam industri manufaktur. Penulis menyajikan beberapa topik yang relevan dengan kebutuhan dalam proses pengukuran dan inspeksi di industri manufaktur dan menyusunnya dalam serangkaian bab dalam buku ini. Penggunaan metrologi untuk kasus-kasus khusus yang tidak umum juga dijelaskan di buku ini. Seiring dengan perkembangan zaman, nanoteknologi menjadi bagian tak terpisahkan dari dunia industri manufaktur. Oleh karenanya, diulas pula isu nanometrologi yang saat ini menjadi tren dalam dunia industri
High sensitivity flexible strain sensor for motion monitoring based on MWCNT@MXene and silicone rubber
No full textAbstract Research on flexible strain sensors has grown rapidly and is widely applied in the fields of soft robotics, body motion detection, wearable sensors, health monitoring, and sports. In this study, MXene was successfully synthesized in powder form and combined with multi-walled carbon nanotube (MWCNT) to develop MWCNT@MXene conductive network-based flexible strain sensors with silicone rubber (SR) substrate. Combining MWCNTs with MXene as a conductive material has been shown to significantly improve the sensor performance, due to MXene’s high conductivity properties that strengthen the MWCNT conductive pathway, increase sensitivity, and improve sensor stability. The sensor is fabricated by a sandwich method consisting of three layers, which enables more accurate and reliable detection of strain changes. The main innovation of this research is the utilization of MWCNT@MXene as a conductive material that optimizes the performance of flexible strain sensors, overcomes the limitations of previous materials, and makes it a more effective solution for long-term applications. Furthermore, the sensor was evaluated to test its performance through sensitivity, linearity, response time, and durability tests. The results showed that the sensor exhibited excellent performance with a high sensitivity of 39.97 over a strain range of 0-100% and excellent linearity (0.99) over a strain of 0–50%. The sensor also has a fast response time of about 70 ms, it also has good stability during low (1–5%) and high (20–100%) strain cycle testing and can withstand up to 1200 loading and unloading cycles. In addition, the sensor effectively detects a wide range of body movements, including finger, wrist and knee movements. These findings show that the electromechanical properties of strain sensors are significantly improved through the use of MWCNT@MXene as a conductive material, so these sensors are considered a promising solution for applications in wearables and body motion monitoring
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