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Selection of regression models for predicting strength and deformability properties of rocks using GA 被引量:9
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作者 Manouchehrian Amin Sharifzadeh Mostafa +1 位作者 Hamidzadeh Moghadam Rasoul Nouri Tohid 《International Journal of Mining Science and Technology》 SCIE EI 2013年第4期492-498,共7页
Recently,many regression models have been presented for prediction of mechanical parameters of rocks regarding to rock index properties.Although statistical analysis is a common method for developing regression models... Recently,many regression models have been presented for prediction of mechanical parameters of rocks regarding to rock index properties.Although statistical analysis is a common method for developing regression models,but still selection of suitable transformation of the independent variables in a regression model is diffcult.In this paper,a genetic algorithm(GA)has been employed as a heuristic search method for selection of best transformation of the independent variables(some index properties of rocks)in regression models for prediction of uniaxial compressive strength(UCS)and modulus of elasticity(E).Firstly,multiple linear regression(MLR)analysis was performed on a data set to establish predictive models.Then,two GA models were developed in which root mean squared error(RMSE)was defned as ftness function.Results have shown that GA models are more precise than MLR models and are able to explain the relation between the intrinsic strength/elasticity properties and index properties of rocks by simple formulation and accepted accuracy. 展开更多
关键词 Regression models Genetic algorithms Heuristics Uniaxial compressive strength Modulus of elasticity Rock index property
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Mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions 被引量:3
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作者 熊良宵 虞利军 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第3期1096-1103,共8页
To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elas... To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elastic modulus, the mass variation,and the compressive strength of cement mortar increase first, and then decrease with increasing erosion time in sodium sulfate and sodium chloride solutions. The relative dynamic elastic moduli and the compressive strengths of cement mortars with water/cement ratios of 0.55 and 0.65 in sodium sulfate solution are lower than those in sodium chloride solution with the same concentration at the420 th day of immersion. The compressive strength of cement mortar with water/cement ratio of 0.65 is more sensitive to strain rate than that with water/cement ratio of 0.55. In addition, the strain-rate sensitivity of compressive strength of cement mortar will increase under attacks of sodium sulfate or sodium chloride solution. 展开更多
关键词 cement mortar mechanical properties relative dynamic elastic modulus compressive strength
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Thermal and Mechanical Properties of Graphene-Titanium Composites Synthesized by Microwave Sintering 被引量:5
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作者 Wen-Zhi Yang Wei-Ming Huang +3 位作者 Zhi-Feng Wang Fu-Jun Shang Wei Huang Bao-Yu Zhang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2016年第8期707-713,共7页
The x wt%graphene-Ti composites(x = 0,0.2,0.3 and 0.4) were obtained using the powder metallurgy method.The X-ray diffraction results demonstrated that the peak intensity of graphene increased monotonically with inc... The x wt%graphene-Ti composites(x = 0,0.2,0.3 and 0.4) were obtained using the powder metallurgy method.The X-ray diffraction results demonstrated that the peak intensity of graphene increased monotonically with increasing graphene content.Furthermore,the number of grain boundary and interface between graphene and matrix increased as graphene increased,which led to a sharp rise of thermal resistances.The thermal conductivity and specific heat capacity of composites initially decreased drastically with addition of graphene,but then increased with increasing graphene content from 0.2 to 0.4 wt%.This phenomenon was connected with the graphene content and the characteristics of Ti matrix(pores,grain boundary and interface between graphene and matrix).The variation of the compressive strength of composites was attributed to the interaction effects of the average grain size of the Ti matrix(d_m) and the volume fraction(V_f) and aspect ratio(A) of graphene. 展开更多
关键词 Graphene Metal-matrix composites Thermal properties compressive strength
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