Xuesong Xing¹, Renjun Xie¹, Yi Wu¹, Zhiqiang Wu¹, Huanqiang Yang^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1719-1735, 2022, DOI:10.32604/fdmp.2022.019799

Abstract

The bonding quality of the cement sheath interface decreases during well completion because of the change in the casing pressure. To explore the root cause of such phenomena, experiments on the mechanical properties and interface bonding strength of a cement sheath have been carried out taking the LS25-1 high-temperature and high-pressure (HTHP) gas field as an example. Moreover, a constitutive model of the cement sheath has been defined and verified both by means of a full-scale HTHP cement sheath sealing integrity evaluation experiment and three-dimensional finite element simulations. The results show that the low initial cementing surface strength is the… More >

Yantao Xu¹, Yufei Han¹, Jianzhang Li¹, Jing Luo², Sheldon Q. Shi³, Jingchao Li¹, Qiang Gao^1,*, An Mao^4,*

Journal of Renewable Materials, Vol.10, No.10, pp. 2519-2541, 2022, DOI:10.32604/jrm.2022.020750

Abstract Traditional formaldehyde-based adhesives rely excessively on petrochemical resources, release toxic gases, and pollute the environment. Plant-derived soybean protein adhesives are eco-friendly materials that have the potential to replace the formaldehyde-based adhesives used to fabricate wood-based panels. However, the poor water resistance, high brittleness, and poor mildew resistance of soybean protein adhesives limit their industrial applications. This article reviews recent research progress in the modification of soybean protein adhesives for improving the bonding performance of adhesives used for wood-based panel fabrication. Modification methods were summarized in terms of water resistance, solid content, and mildew resistance. The modification mechanisms and remaining problems… More >

Biyao Zhai, Lu Liu, Shunying Ji^*

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.1, pp. 1-22, 2022, DOI:10.32604/cmes.2022.018652

Abstract Freezing in ice rubble is a common phenomenon in cold regions, which can consolidate loose blocks and change their mechanical properties. To model the cohesive effect in frozen ice rubble, and to describe the fragmentation behavior with a large external forces exerted, a freeze-bond model based on the dilated polyhedral discrete element method (DEM) is proposed. Herein, imaginary bonding is initialized at the contact points to transmit forces and moments, and the initiation of the damage is detected using the hybrid fracture model. The model is validated through the qualitative agreement between the simulation results and the analytical solution of… More >

Jinghua Wang¹, Leian Zhang¹, Xuemei Huang^1,*, Jinfeng Zhang², Chengwei Yuan¹

Energy Engineering, Vol.119, No.1, pp. 407-418, 2022, DOI:10.32604/EE.2022.016439

Abstract Transverse crack often occurs in the trailing edge region of the blade when subjected to the excessive edgewise fatigue load. In this paper a refined model was established through local mesh refinement methods in order to investigate the initiation mechanism of crack and its extension in blade trailing edge. The material stress around the crack in trailing edge region under different thicknesses is calculated based on the fracture mechanics theory. The factors affecting the fatigue robustness of blade trailing edge are concluded by investigating the results of finite element analysis and coupons test. Compared with the laminate, the lower fatigue… More >

Zhigang Wu^1,#, Sicheng Chen^1,#, Jiankun Liang², Lifen Li¹, Xuedong Xi^3,4, Xue Deng¹, Bengang Zhang^3,*, Hong Lei^4,*

Journal of Renewable Materials, Vol.9, No.11, pp. 1959-1972, 2021, DOI:10.32604/jrm.2021.016786

Abstract Alkali lignin was processed by plasma and then used in modification of phenol formaldehyde resin in this study. Chemical structural changes of lignin which was processed by plasma as well as bonding strength, tensile property, curing performance and thermal property of the prepared phenol formaldehyde resin which was modified by the plasma processed lignin were analyzed. Results demonstrated that: (1) Alkali lignin was degraded after the plasma processing. The original groups were destroyed, and the aromatic rings collected abundant free radicals and oxygen-containing functional groups like hydroxyls, carbonyls, carboxyls and acyls were introduced into increase the reaction activity of lignin… More > Graphic Abstract

Long Zheng, Yiqiang Wu, Shu Wang, Guoan Sheng, Baorong Sun, Yingfeng Zuo^*

Journal of Renewable Materials, Vol.9, No.10, pp. 1729-1739, 2021, DOI:10.32604/jrm.2021.015143

Abstract This study was designed to solve the problem of large waste volume from bamboo processing residues in recent years. Using magnesium oxychloride (MO) cementitious material as the main material and bamboo residue (BR) as the reinforcing material, a BR/MO composite material was prepared. The effects of BR amount on the molding properties, mechanical strength, and water resistance of BR/MO composites were examined and discussed. Scanning electron microscopy (SEM), X-ray diffractometry (XRD), and thermogravimetric analysis were used to characterize composite microscopic morphology, crystalline structure, and heat resistance. The results showed that, when the BR content was 1.00% (by wt), the flowability… More >

Antonio Pizzi^*

Journal of Renewable Materials, Vol.9, No.8, pp. 1345-1364, 2021, DOI:10.32604/jrm.2021.015663

Abstract Collagen powder hydrolysates were reacted with a solution of commercial mimosa bark tannin extract. The mixture was prepared at ambient temperature and prepared at 80°C to determine what reactions, if any, did occur between the collagen protein through its amino acids and the polyphenolic condensed tannin. The reaction products obtained were analyzed by matrix assisted laser desorption ionization time-of-flight (MALDI ToF) mass spectrometry. Reactions between the two materials did appear to occur, with the formation of a relatively small proportion of covalent and ionic linkages at ambient temperature but a considerable proportion of covalent linkages tannin-protein amino acids and the… More >

Jihong Hu, Mingqing Sun^*, Wei Huang, Yingjun Wang

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.1, pp. 191-207, 2021, DOI:10.32604/cmes.2021.015365

Abstract Strain hardening cement-based composites (SHCC) beam externally bonded with glass fiber-reinforced polymer (FRP) plate was examined under three-point flexural test. The effects of the type of substrate used (plain cement mortar vs. SHCC), the use or not of a FRP plate to strengthen the SHCC beam, and the thickness of the FRP plate on the flexural performances were studied. Results show that the ultimate load of SHCC beams strengthened with FRP plate has improved greatly in comparison with plain SHCC beams. The deformation capacity of beams makes little change with an increase in the thickness of FRP plates. The formation… More >

Suxia Li^1,2, Haiyang Zhang^1,*, Biqing Shu^1,3, Liangsong Cheng¹, Zehui Ju¹, Xiaoning Lu^1,*

Journal of Renewable Materials, Vol.9, No.7, pp. 1225-1237, 2021, DOI:10.32604/jrm.2021.014364

Abstract The wood friction welding technique with its high bonding strength, low cost, high efficiency, and without any adhesive has been increasing concern in China. Moso bamboo (Phyllostachys pubescens) and poplar (Populus sp.) are widely planted and used in the furniture industry, interior decoration, and wood structure construction in China. The aim of this work was to investigate the bonding performance of moso bamboo dowel rotation welded joints with different dowel/receiving hole diameter ratios. The results indicated that the ratio of dowel/receiving hole diameter was an important parameter that influenced the welding performance. The bonding strength of the bamboo-to-poplar welded joints… More >

Zhihang Wang^1,*, Jinyu Xu^1,2, Xin Meng¹, Conigjin Zhu¹

Journal of Renewable Materials, Vol.9, No.6, pp. 1157-1168, 2021, DOI:10.32604/jrm.2021.014878

Abstract In this paper, the specimens of polymer-cement composites after 1 d, 7 d, 15 d, and 30 d aging without aging and UV aging are subjected to fixed extension test and tensile test. By observing the mode of the composite in the fixed-elongation test, and measuring the elastic recovery rate, tensile strength, elongation at break, peak tensile strain, tensile toughness and pre-peak tensile toughness of the composite, the effects of UV aging on the bonding and the tensile properties of the composite were studied. And combining with scanning electron microscopy experiments, the micro-mechanism of the effect of ultraviolet aging on… More >