Jun Wu^1,*, Kui Hu¹, Yiwei Cheng², Ji Wang¹, Chao Deng^2,*, Yuanhan Wang³

Structural Durability & Health Monitoring, Vol.13, No.3, pp. 317-329, 2019, DOI:10.32604/sdhm.2019.05571

Abstract Residual useful life (RUL) prediction is a key issue for improving efficiency of aircraft engines and reducing their maintenance cost. Owing to various failure mechanism and operating environment, the application of classical models in RUL prediction of aircraft engines is fairly difficult. In this study, a novel RUL prognostics method based on using ensemble recurrent neural network to process massive sensor data is proposed. First of all, sensor data obtained from the aircraft engines are preprocessed to eliminate singular values, reduce random fluctuation and preserve degradation trend of the raw sensor data. Secondly, three kinds of recurrent neural networks (RNN),… More >

Guang Chen^1,*, Keqin Ding¹, Qibo Feng², Xinran Yin¹, Fangxiong Tang¹

Structural Durability & Health Monitoring, Vol.13, No.3, pp. 289-301, 2019, DOI:10.32604/sdhm.2019.05144

Abstract The grating ends bonding fiber Bragg grating (FBG) sensor has been widely used in sensor packages such as substrate type and clamp type for health monitoring of large structures. However, owing to the shear deformation of the adhesive layer of FBG, the strain measured by FBG is often different from the strain of actual matrix, which causes strain measurement errors. This investigation aims at improving the measurement accuracy of strain for the grating ends surface-bonded FBG. To fulfill this objective, a strain transfer equation of the grating ends bonding FBG is derived, and a theoretical model of the average strain… More >

Rui Lu¹, Zhanjun Wu¹, Qi Zhou¹, Hao Xu^1,*

Structural Durability & Health Monitoring, Vol.13, No.3, pp. 267-287, 2019, DOI:10.32604/sdhm.2019.06323

Abstract Structural health monitoring (SHM) is a research focus involving a large category of techniques performing in-situ identification of structural damage, stress, external loads, vibration signatures, etc. Among various SHM techniques, those able to monitoring structural deformed shapes are considered as an important category. A novel method of deformed shape reconstruction for thin-walled beam structures was recently proposed by Xu et al. [1], which is capable of decoupling complex beam deformations subject to the combination of different loading cases, including tension/compression, bending and warping torsion, and also able to reconstruct the full-field displacement distributions. However, this method was demonstrated only under… More >

Alex Kost¹, Wael A. Altabey^2,3,4, Mohammad Noori^1,2,*, Taher Awad⁴

Structural Durability & Health Monitoring, Vol.13, No.3, pp. 247-266, 2019, DOI:10.32604/sdhm.2019.07025

Abstract A proof-of-concept indirect tire-pressure monitoring system is developed using artificial neural networks to identify the tire pressure of a vehicle tire. A quarter-car model was developed with MATLAB and Simulink to generate simulated accelerometer output data. Simulation data are used to train and evaluate a recurrent neural network with long short-term memory blocks (RNN-LSTM) and a convolutional neural network (CNN) developed in Python with Tensorflow. Bayesian Optimization via SigOpt was used to optimize training and model parameters. The predictive accuracy and training speed of the two models with various parameters are compared. Finally, future work and improvements are discussed. More >

Xiaoyu Chen*, Jie Zhu

Journal of Renewable Materials, Vol.7, No.10, pp. 983-996, 2019, DOI:10.32604/jrm.2019.07325

Abstract With the rapid development of textile industry, a large amount of dye-contaminated effluents was produced and caused serious environmental problem. To remove the dye from effluents, adsorption materials have been applied because of their relatively cheap, high efficiency, and easy handling. In this study, a novel composite hydrogel bead with unique multilayer flake structure was fabricated by alginate, acrylamide and attapulgite for dye adsorption. Acrylamide was grafted polymerization onto alginate to obtain alginate-g-poly(acrylamide). Then alginate-g-poly(acrylamide) was cross-linked by Ca²⁺ ions in present of attapulgite to form composite hydrogel bead. Scanning electron microscopy (SEM) results show that the freeze dried composite… More >

Joyce de P. Cipriano², N. C. Zanini¹, I. R. Dantas¹, D. R. Mulinari^1,*

Journal of Renewable Materials, Vol.7, No.10, pp. 1047-1053, 2019, DOI:10.32604/jrm.2019.00001

Abstract The use of natural fibers as an additive in polymeric matrices has attracted interest of the automotive industries, for its low cost, mechanical properties, biodegradability and lightness. However, the hydrophilic nature of the fiber makes polymer compatibility difficult. Fiber surface treatments can be used to enhance the fiber/matrix interface. In the present work, polypropylene (PP) composites reinforced with fibers from macadamia nutshell were obtained and characterized. Macadamia nutshell fibers were treated by an alkaline treatment with sodium hydroxide (NaOH 4%) to improve adhesion between fibers and matrix. Fibers were characterized by techniques of Scanning Electron Microscopy (SEM) and X-Ray Diffraction… More >

Yingchun Gong^1,#,*, Fenglu Liu^2,#, Zhaopeng Tian¹, Guofang Wu¹, Haiqing Ren¹, Cheng Guan²

Journal of Renewable Materials, Vol.7, No.10, pp. 941-956, 2019, DOI:10.32604/jrm.2019.07354

Abstract Japanese larch is one of the main plantation tree species in China. A lack of engineered wood products made by Japanese larch , limits its application in wood structures. In this study, based on optimum process para meters, such as pressure (1.2 MPa), adhesive spread rate (200 g/m 2 ) and adhesive (one component polyurethane), the mechanical properties of Japanese larch made cross laminated timber ( with different lay ups were evaluated by means of the static method . Results of this study show ed that variations in lay ups significant ly affected the mechanical properties of CLT. The strength… More >

Yufeng Ma¹, Xuanang Gong¹, Bing Xie¹, Xiang Geng¹, Puyou Jia^2,*

Journal of Renewable Materials, Vol.7, No.10, pp. 1037-1046, 2019, DOI:10.32604/jrm.2019.07454

Abstract In order to improve the mechanical properties without reducing its flame retardancy of phenolic foams (PFs), 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was introduced in the structure of cashew nut shell liquid (CNSL) to improve its flame retardant, and the product of DOPO grafting CNSL (DOPO-g-CNSL) was obtained to modify phenolic resin, and to prepare DOPO-g-CNSL modified PFs (DCMPFs). The structures of DOPO-g-CNSL were verified by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H-NMR). Compared with CNSL, thermal stability of DOPO-g-CNSL was decreased and Ti decreased by 3.53%, but the residual carbon (800°C) was increased by 35.05%. Compared with pure PF,… More >

Antonio Greco*, Francesca Ferrari, Raffaella Striani, Carola Esposito Corcione

Journal of Renewable Materials, Vol.7, No.10, pp. 1023-1035, 2019, DOI:10.32604/jrm.2019.07778

Abstract This work is aimed at the development of new green composite materials through the incorporation of the solid organic waste (SOW) in a thermoplastic matrix. After being ground, the organic waste was exposed to a sterilization process, though an autoclave cycle, in order to obtain a complete removal of the bacterial activity. The SOW was found to have a high amount of water, about 65-70%, which made uneconomical its further treatment to reduce the water amount. Therefore, a water soluble polymer, poly (vinyl alcohol) (PVA) was chosen in order to produce SOW based blends. However, in order to reduce the… More >

Fei Song¹, Puyou Jia^1,*, Yanan Xiao², Caiying Bo¹, Lihong Hu¹, Yonghong Zhou^1,*

Journal of Renewable Materials, Vol.7, No.10, pp. 1011-1021, 2019, DOI:10.32604/jrm.2019.08044

Abstract Phenolic foams (PFs) as thermal insulation material with outstanding flame retardancy are required to match society’s ever expanding safety expectations; however, a trade off exists between flame retardancy and toughness. Here, for the first time, we synthesized a novel reactive phosphorus containing tung oil based derivative and used it to toughen PF, resulting in PFs with a combination of excellent mechanical properties and flame retardancy. Compared with pure PF, the modified PFs exhibit enhanced mechanical properties, with specific compressive and flexural strengths as high as 5.67 MPa and 12.46 MPa, which represent increases of 90.67% and 178.7% over those of… More >