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Copyright of Advanced Textile Technology is the property of Zhejiang Sci-Tech University Magazines and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Whether domestic or foreign, the utilization of phosphogypsum (PG) resources is not satisfactory. A chemical plant in Guizhou produces phosphoric acid through a semi-aqueous process to obtain the byproduct hemihydrate phosphogypsum (HPG), which has a certain gelling activity. If this feature of HPG can be fully utilized, it can replace cement as a cementing material to prepare mine-filling materials. Utilizing HPG for goaf filling can not only reduce the environmental protection problems caused by the surface discharge of PG but also eliminate the hidden safety hazards in the goaf. At present, when HPG is used to prepare mine-filling cementitious materials, HPG will be consolidated into a block and lose its gelling activity when it is stacked for a certain period of time. The gelling performance of the HPG in the storage state appears to decline. Based on the indoor HPG crystal water detection and uniaxial compression test and setting four different storage temperatures (20 ℃, 40 ℃, 60 ℃, and 80 ℃), this study explored the changes in the mass fraction of the crystal water of HPG samples under different storage temperatures. The compressive strength development law of HCM prepared after storage and microscopic analysis methods, such as scanning electron microscopy, were used to study the influence mechanism of the storage temperature on its strength. Results show that the stacking temperature has a significant effect on the gelling performance of HPG. A high stacking temperature will speed up the conversion of free water in the HPG sample to crystal water and inhibit the strength development of the HCM prepared after stacking. Data standardization was used to predict the compressive strength of samples after storage at different temperatures, which is confirmed to be in good agreement with the measured values. The microscopic analysis found that the storage temperature mainly affects the supersaturation of the system, and the microscopic morphology of the HCM prepared after storage at different temperatures is different.

Taking the mechanized mining of a very broken ore body in the Lingshan mining area of Linglong Gold Mine as the research background, 11 measuring areas were selected by using the N-type rebound instrument to carry out the rebound test, and the core drilling at the test point was processed as the standard rock sample for acoustic test and uniaxial compression test. Through the analysis of the test results, the relationship between rebound value, longitudinal wave velocity, and uniaxial strength is obtained. It can be seen that the rebound value is exponentially correlated with the uniaxial compressive strength of rock, while the fitting curve of longitudinal wave velocity and rock strength is poor. On this basis, the binary regression analysis of the acoustic-rebound combination is carried out, and the correlation coefficient of the power function is the best by comprehensive comparison. The research results can provide help for the strength prediction and excavation mining analysis of Lingshan rock mass in Linglong Gold Mine. [ABSTRACT FROM AUTHOR]

The effects of thermo-oxidative aging on the mechanical properties of three-dimensional orthogonal carbon/glass fiber/bismaleimide composite (3D-CF/GF/BMI composite) and laminated carbon/glass fiber/bismaleimide composite (LM-CF/GF/BMI composite) were studied by means of three-point bending and inter-laminar shear tests. The mass loss behavior, infrared spectra, macroscopic and microscopic morphology, bending properties and inter-laminar shear properties of the composites were analyzed at different aging time. The results show that a large amount of resin decomposition caused by thermal oxygen aging produces a large number of cracks on the surface and inside the composites, and the interface properties continue to decline. Eventually, the overall mechanical properties of the composite material decrease, resulting in the decline of the overall mechanical properties of the composite, but the performance retention rate of the 3D-CF/GF/BMI composite is always higher than that the of LM-CF/GF/BMI composite. This is because Z-binder yarns in the 3D-CF/GF/BMI composite exist, and the obstruction of the cracks propagating along the layers by Z-binder yarns can make all fibers together to resist external forces in the case of severe degradation of resin and interfacial properties. The "modified random process model" is used to predict all the bending strength of 3D-CF/GF/BMI composite aged at 200℃ for 180 days. The prediction error is less than 10%, indicating that the model is reliable.

In order to solve the problems of ecological environment caused by the shortage of filling materials and solid wastes in the goaf of coal mine, the paper puts forward some suggestions to solve these problems, in the paper, influencing factors of paste filling body strength were analyzed, and sample strength of filling body was determined by orthogonal test, the correlation between the influence factors and the strength of the filling body was determined with grey relational analysis method, and an improved BP strength prediction model was built, in which the factors affecting the strength of solid waste paste filling are input layer and the strength of the filling body is output layer. The strength test data obtained from orthogonal test were used as training samples and test samples of the network, the fitting ability and generalization ability of network data were tested by analog simulation. Test results show that the established prediction model has fast convergence speed and high accuracy, and its prediction accuracy reaches 93.75%, which indicates accurate prediction of the filling body strength can be realized.

The stress concentration caused by notches is a common engineering issue for composite structure application. 3D braided composite possess excellent damage tolerance compared to common laminates. The tensile properties of 3D braided composite with open-hole and un-notched were experimentally examined. The mechanic properties of 3D braided composite in other directions are predicted using FGM (Fabric Geometry Model) and finite element analysis. The stress distributions around the hole and perpendicular to the loading direction are analyzed based on Abaqus software. The simulation results were compared with Lekhnitskii's analytical study. The open-hole strength of 3D braided composite was predicted respectively using Average stress failure criteria, Point stress failure criteria (PSC), and also the progressive failure analysis based on different failure criteria. The predicted strength results were compared to the experimental values. The results show the PSC predicted strength matched the experiment, while the progressive failure analysis can predict the failure initiation, propagation and final failure mode.

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The moisture absorption properties of carbon fiber reinforced plastics (CFRP) laminates treated with three kinds of hygrothermal environments (relative humidity 85% RH, temperature 25, 70, 85℃ respectively) were investigated by accelerated moisture absorption method. Tensile, compressive and shear tests were carried out to study the effect of hygrothermal conditions on the mechanical behavior of CFRP laminates. Meanwhile, the damage mechanism of CFRP laminates in hygrothermal environment was analyzed by scanning electron microscopy and infrared spectroscopy. Finally, a formula which could predict the mechanical properties of CFRP laminates in hygrothermal environments was proposed by least square method. The results show that the moisture absorption characteristics of CFRP laminates in preliminary stage accords with Fick's law well. At the same humidity, the CFRP's moisture absorption speeds, the moisture saturation contents and times are increased with the increment of the environmental temperature. The mechanical properties of CFRP laminates in 90°tensile test and shear test are decreased most obviously. Water molecules are associated with epoxy resin through hydrogen bonds after the treatment in hygrothermal environment, however, there is no chemical structure change in the components of the CFRP laminate. The formula of mechanical performance degradation under different hygrothermal conditions is basically consistent with the experimental results.

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The uniaxial compressive strength is usually used as a characterization index for quality evaluation of in-situ cemented backfill. The backfill strength couldn't be obtained quickly and accurately in the field engineering, hence, it is necessary to establish an in-situ cemented backfill strength prediction model for easily obtaining parameters. Based on internal links of physicomechanical parameters of in-situ cemented backfill, a relation between UCS and P-wave modulus was established from the perspective of dimensional balance. According to the test data of density, P-wave velocity and coring strength of in-situ cemented backfill of C and I mine, the strength prediction model based on P-wave modulus was obtained by the linear fitting method. The comparative analysis of the fitting effect of the strength prediction models indicated that the P-wave modulus was positively correlated with the coring strength, and the fitting effect was good, which proved the strength prediction model of the in-situ cemented backfill had high accuracy and strong practicability. [ABSTRACT FROM AUTHOR]

The second time develop of the ANSYS was realized by using APDL language, and an ovoid sectional multi-scale unit cell model for fiber bundle section with pre-made defects was established. At first the initial modulus, the strength and the ultimate strain of fiber bundle were calculated. Then the unit cell model of C/SiC woven composites was established according to the SEM photographs. By introducing the periodic boundary conditions, the initial anisotropic constants of C/SiC woven composites were predicted. The failure criteria proposed by Linde was utilized to set up the progressive damage mode,and the C/SiC plain weave composites with defects under unidirectional tension was simulated. So,the damage evolution process of the fiber bundle could be interpreted, when the unit cell of C/SiC plain weave composites was under the unidirection load. The numerical results show that the proposed model accurately captures the data from the experiments, which demonstrates the validity of the present analytical model. Furthermore, the numerical model provides an alternate way to design and predict the mechanical properties of plain weave composites.

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objectives] The reliability of propeller stress has a great influence on the safe navigation of a ship. To predict propeller stress quickly and accurately,[Methods] a new numerical prediction model is developed by coupling the Boundary Element Method(BEM)with the Finite Element Method (FEM). The low order BEM is used to calculate the hydrodynamic load on the blades, and the Prandtl-Schlichting plate friction resistance formula is used to calculate the viscous load. Next, the calculated hydrodynamic load and viscous correction load are transmitted to the calculation of the Finite Element as surface loads. Considering the particularity of propeller geometry, a continuous contact detection algorithm is developed; an automatic method for generating the finite element mesh is developed for the propeller blade; a code based on the FEM is compiled for predicting blade stress and deformation; the DTRC 4119 propeller model is applied to validate the reliability of the method; and mesh independence is confirmed by comparing the calculated results with different sizes and types of mesh.[Results] The results show that the calculated blade stress and displacement distribution are reliable. This method avoids the process of artificial modeling and finite element mesh generation, and has the advantages of simple program implementation and high calculation efficiency.[Conclusions] The code can be embedded into the code of theoretical and optimized propeller designs, thereby helping to ensure the strength of designed propellers and improve the efficiency of propeller design.

In order to predict the strength of a composite only based on the mechanical properties of its constituent fiber and matrix materials measured independently, 3 challenging problems must be resolved with high success rate. First, internal stresses in the fiber and matrix must be accurately evaluated. Second, efficient failure detection of the composite in terms of the internal stresses, i.e., the micromechanical strength theory, must be achieved. Last but not the least, the input data of in-situ strengths of the matrix, which can hardly be measured through experiments, must be correctly determined according to its original counterparts available independently. Each of these problems is by no means easy to deal with. This is why the prediction of composite strength is extremely difficult. The bridging model, originally established by HUANG Zheng-ming and further developed to a powerful theory, presents a systematic approach towards solving all of the 3 problems. This paper briefly summarizes the theory by focusing on some of the latest advancements. A number of further research topics are also highlighted. [ABSTRACT FROM AUTHOR]