North University of China

Shanxi Zhongbei New Material Technology Co., Ltd.

Chaoyang Wu

Guizhe Zhao

Yaqing Liu

Qihui Chen

Guanyu Han

Yanan Liu

Yong Gao

An optimizing method for a molding process of a part made of a fiber-reinforced polymer composite is provided. A finite element method is adopted to perform thermochemical analysis of a macroscopic model of the part and thermomechanics analysis of a microscopic model of the part, so as to simulate temperature gradient, curing degree, and residual stress of the part during the molding process. A genetic algorithm is executed, with simultaneous minimization of temperature gradient, molding time, and residual stress as an optimization goal and a curing process curve as a parameter variable, to achieve the simultaneous multi-objective optimization of molding process parameters, so as to obtain an optimized molding process.

Optimizing method for molding process of fiber-reinforced polymer composite parts

A thermal compensation design and implementation method for near-net-shape molding of a thermoset composite part based on temperature and curing degree fields is provided. A minimum symmetric unit model is established based on sizes of the part and a mold and ambient temperature. A curing kinetic model and a heat transfer model are established. A molding temperature curve is written into a subprogram. A simulated thermal compensation is performed on a region whose temperature is lower than a molding temperature with a difference of greater than or equal to 5% of the molding temperature until the temperature difference of individual regions is less than 5% of the molding temperature. The simulated thermal compensation is then performed on those regions with a curing degree less than or equal to 0.9. A thermal compensation device is assembled according to the thermal compensation scheme for experimental verification.

Thermal compensation design and implementation method for a near-net-shape (NNS) molding of thermoset composite part based on temperature field and curing degree field

A lightweight, low-thickness, durable, and reliable multi-band radar stealth-bulletproof integrated metamaterial includes a ceramic layer, an ultrahigh molecular weight polyethylene (UHMWPE) fiber composite bulletproof layer, a graphene-based metamaterial filter layer, an UHMWPE fiber composite attenuation layer, and a carbon fiber composite reflective layer stacked in sequence. The two UHMWPE fiber composite layers are configured to attenuate radar waves. The circuit resonance of the graphene-based metamaterial filter layer is configured to generate a passband and a stopband simultaneously. The bulletproof layer and the attenuation layer are controlled by the graphene-based metamaterial filter layer in terms of working conditions in different radar frequency bands to establish a structure capable of generating λ/4 resonance at both low and high frequencies, so as to arrive at a stealth-bulletproof integrated metamaterial with small thickness and excellent dual-band radar wave absorption capability.

Lightweight, low-thickness, durable and reliable multi-band radar stealth-bulletproof integrated metamaterial

An efficient microwave-assisted preparation method with one-step simultaneous reduction/embedding of a metal monatomic-doped reduced graphene oxide dielectric material. A metal salt aqueous solution is added to a graphene oxide aqueous dispersion to obtain a mixed dispersion. The mixed dispersion is mechanically stirred, such that the metal salt fully interacts with the graphene oxide, and the metal ions are uniformly loaded on a surface of the graphene oxide sheets through the interaction between metal ions and the oxygen-containing functional groups of the graphene oxide. The mixed dispersion is freeze-dried to obtain a metal salt/graphene oxide complex, which is subjected to a microwave treatment in the presence of an initiator in a microwave oven to allow reduction to obtain the metal monatomic-doped reduced graphene oxide dielectric material. An application of the metal monatomic-doped reduced graphene oxide dielectric material is also provided.

Efficient microwave preparation method with one-step simultaneous reduction/embedding and application of metal monatomic-doped reduced graphene oxide dielectric material

This disclosure relates to slow- and controlled-release fertilizers (S-CRF), and more particularly to a microelement amino acid chelate-urea formaldehyde (UF) slow-release fertilizer and a method for preparing the same by reactive extrusion. The microelement amino acid chelate-UF slow-release fertilizer includes a biodegradable UF polymer and a microelement amino acid chelate. The macromolecular chains of the biodegradable UF polymer interpenetrate in the cross-linked network structure of the chelate, so as to form a polymer composite with a semi-interpenetrating network structure.

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Taiyuan, China

Chaoyang Wu