Xue-Qin Li¹, Lu-Kai Song^2,3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 665-684, 2024, DOI:10.32604/cmes.2024.048445

Abstract Fatigue reliability-based design optimization of aeroengine structures involves multiple repeated calculations of reliability degree and large-scale calls of implicit high-nonlinearity limit state function, leading to the traditional direct Monte Claro and surrogate methods prone to unacceptable computing efficiency and accuracy. In this case, by fusing the random subspace strategy and weight allocation technology into bagging ensemble theory, a random forest (RF) model is presented to enhance the computing efficiency of reliability degree; moreover, by embedding the RF model into multilevel optimization model, an efficient RF-assisted fatigue reliability-based design optimization framework is developed. Regarding the low-cycle fatigue reliability-based design optimization of… More >

Hayder Kareem Sakran^1,2, Mohd Sharizal Abdul Aziz^1,*, Chu Yee Khor³

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 109-137, 2024, DOI:10.32604/cmes.2024.047245

Abstract The centrifugal pump is a prevalent power equipment widely used in different engineering patterns, and the impeller blade wrap angle significantly impacts its performance. A numerical investigation was conducted to analyze the influence of the blade wrap angle on flow characteristics and energy distribution of a centrifugal pump evaluated as a low specific speed with a value of 69. This study investigates six impeller models that possess varying blade wrap angles (95°, 105°, 115°, 125°, 135°, and 145°) that were created while maintaining the same volute and other geometrical characteristics. The investigation of energy loss was conducted to evaluate the… More > Graphic Abstract

Dongsheng Jia, Yingjie Xu^*, Liangdi Wang, Jihong Zhu, Weihong Zhang

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 171-199, 2024, DOI:10.32604/cmes.2024.046703

Abstract The abalone shell, a composite material whose cross-section is composed of inorganic and organic layers, has high strength and toughness. Inspired by the abalone shell, several multi-layer composite plates with different layer sequences and thicknesses are studied as bullet-proof material in this paper. To investigate the ballistic performance of this multi-layer structure, the complete characterization model and related material parameters of large deformation, failure and fracture of Al₂O₃ ceramics and Carbon Fiber Reinforced Polymer (CFRP) are studied. Then, 3D finite element models of the proposed composite plates with different layer sequences and thicknesses impacted by a 12.7 mm armor-piercing incendiary… More >

Jiaqi Wu¹, Li Zhuo^1,*, Jianliang Pei¹, Yao Li², Hongqiang Xie¹, Jiaming Wu¹, Huaizhong Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 621-645, 2024, DOI:10.32604/cmes.2024.046398

Abstract The surrounding geological conditions and supporting structures of underground engineering are often updated during construction, and these updates require repeated numerical modeling. To improve the numerical modeling efficiency of underground engineering, a modularized and parametric modeling cloud server is developed by using Python codes. The basic framework of the cloud server is as follows: input the modeling parameters into the web platform, implement Rhino software and FLAC^3D software to model and run simulations in the cloud server, and return the simulation results to the web platform. The modeling program can automatically generate instructions that can run the modeling process in… More >

KEMIN WANG, LIFEI HE

Journal of Polymer Materials, Vol.36, No.3, pp. 253-260, 2019, DOI:10.32381/JPM.2019.36.03.5

Abstract This study proposes a simple approach for the fabrication of microspherical catalysts with a hierarchical porous structure. The cross-linked porous microspheres with catalytic ability were prepared directly from small-molecular monomers via low-temperature phase-separation photopolymerization of water/oil suspension. The morphology, pore size, chemical structure, and thermal stability of the obtained porous microspheres were characterized by SEM, Mercury Intrusion Porosimetry, FTIR, and TGA. The porous microspheres directly served as an acid catalyst for the condensation reaction of benzaldehyde and ethylene glycol, which exhibited superior catalytic activity and recyclability. The results indicated that such porous microspheres have great potential in the application of… More >

AMRITA SHARMA, P. P. PANDE

Journal of Polymer Materials, Vol.36, No.2, pp. 175-194, 2019, DOI:10.32381/JPM.2019.36.02.6

Abstract ‘Comb-like polymers’ are a special class of polymers. These are consisting of two types of chains, first one is the backbone chain and second is long side chains. The structure of such a polymer is very similar to hair comb. Usually, every monomer unit in the backbone has a long n-alkyl side chain. Comb like polymers have an intrinsic ability towards forming ordered structure. Now-a-days, these polymers find wide range of applications because of their excellent physicochemical properties. Some applications are in preparation of polysoaps (polymeric disinfectants), as dispersing agent for ink and paints, textile industry, in surface modification of… More >

XIAOYAN LIU^a,*, XU CHEN^a, HONGXING ZHANG^b, CHANGJUN ZHANG^a, SHIYUAN YANG^a, GUANGQUAN LI^a

Journal of Polymer Materials, Vol.36, No.2, pp. 121-132, 2019, DOI:10.32381/JPM.2019.36.02.2

Abstract In this work, three in situ impact polypropylene copolymer(IPC) samples were prepared through Ziegler-Natta catalyst only changing the feed composition (ethylene to ethylene and propylene molar ratio, C2/C2+C3) in gas-phase polymerization reactor. Polymer (IPC) were characterical by solvent classification, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), successive self-nucleation and annealing (SSA), nuclear magnetic resonance(13C-NMR) and scanning electron microscopy(SEM). The mechanical properties of IPC samples were tested.The results indicate that with similar ethylene content, the feed composition which determines the content and structure of EPR and EbP component in IPC, further impacts the rubber phase size and distribution in IPC,… More >

İBRAHIM KARTERI^a,b,*, MUSTAFA ÖZYEŞILDAĞ^b

Journal of Polymer Materials, Vol.38, No.1-2, pp. 167-177, 2021, DOI:10.32381/JPM.2021.38.1-2.13

Abstract This study aims to provide a comprehensive account of chemically reduced graphene oxide (RGO) and decabromodiphenyl ethane (DBDPE) filled acrylonitrile-butadiene-styrene (ABS) multifunctional filaments for fused deposition modeling (FDM) applications. ABS/RGO with DBDPE nanocomposites (ABS-GDM) were fabricated by single-screw extrusion at a diameter of 1.75 mm. The proportion of RGO and DBDPE for the ABS-GDM filaments was set to 0.75 wt%. The properties of the ABS-GDM were determined using optical, mechanical, thermal, and morphological characteristics (using scanning electron microscopy). A three-dimensional (3D) model was successfully printed using the developed ABS-GDM filaments for FDM 3D printing. These ABS-GDM have the potential to… More >

A. MADHAN KUMAR¹, K. JAYAKUMAR^2,*, M. SHALINI³

Journal of Polymer Materials, Vol.39, No.3-4, pp. 269-281, 2022, DOI:10.32381/JPM.2022.39.3-4.7

Abstract Polylactic acid (PLA) is the most popular thermoplastic biopolymer providing a stiffness and strength alternative to fossil-based plastics. It is also the most promising biodegradable polymer on the market right now, thus gaining a substitute for conservative artificial polymers. Therefore, the current research focuses on synthesizing and mechanical characterization of particlereinforced PLA composites. The hot compression molding technique was used to fabricate PLA-based composites with 0, 2.5, 5, and 7.5 weight % of sawdust, rice husk, and bagasse particle reinforcements to enhance the performance of the PLA. The pellets of PLA matrix were taken with an average size of 3… More >

ALOK K. SAHU^a, RAJSHREE VIJAYVARGIYA^a, R. M. SARVIYA^b

Journal of Polymer Materials, Vol.39, No.3-4, pp. 183-193, 2022, DOI:10.32381/JPM.2022.39.3-4.1

Abstract HDPE material is found to be best suited material for the manufacturing of floating bed structure for the solar photovoltaic (PV) system due to its light weight and excellent mechanical & chemical resistant properties. However, the major restriction in this regard is the limited engineering design and also the effect of UV radiations present in the natural environment that leads to the degradation of the plastic materials. Hence, in order to improve its UV stability carbon black is incorporated into it as UV resistant additive and hollow cubical floats of such HDPE/carbon black composite material has been manufactured by rotational… More >