CAJ | 학술논문

构建水滑石(Mg_3Al-LDHs-Cl-nH_2O)周期性计算模型,采用密度泛函理论-赝势平面波法的CASTEP/LDA(局域密度近似)程序,在CA-PZ水平上对模型进行几何全优化和弹性常数计算.从弹性常数G_(ij)、切变模量、杨氏模量和泊松比等方面研究了层间水分子含量(n)对材料力学性质的影响.计算结果表明,层间水分子含量对材料的力学性质有很大的影响.层间水分子能提高体系总体的抗压性能,当n=1时,材料的抗压性能最好;当n=2时,材料的抵抗剪切变形的能力最差,体系最柔软.层间水分子对材料杨氏模量的影响较大,对泊松比的影响并不明显.且层间水分子对材料横向的力学性能起到平均化作用,最终使材料在X轴和Y轴方向上的抗匮陛能和膨胀率趋于一致.
구건수활석(Mg_3Al-LDHs-Cl-nH_2O)주기성계산모형,채용밀도범함이론-안세평면파법적CASTEP/LDA(국역밀도근사)정서,재CA-PZ수평상대모형진행궤하전우화화탄성상수계산.종탄성상수G_(ij)、절변모량、양씨모량화박송비등방면연구료층간수분자함량(n)대재료역학성질적영향.계산결과표명,층간수분자함량대재료적역학성질유흔대적영향.층간수분자능제고체계총체적항압성능,당n=1시,재료적항압성능최호;당n=2시,재료적저항전절변형적능력최차,체계최유연.층간수분자대재료양씨모량적영향교대,대박송비적영향병불명현.차층간수분자대재료횡향적역학성능기도평균화작용,최종사재료재X축화Y축방향상적항궤폐능화팽창솔추우일치.
A periodical model for Mg_3Al-LDHs-Cl-nH_2O has been proposed. A geometry optimization and elastic constant calculation for the layered double hydroxides (LDHs) were carried out using the CASTEP/LDA (local density approximation) procedure at the CA-PZ level. The influence of interlayer water content (n) on the mechanical properties of the materials was investigated by analyzing the elastic constants C_(ij), shear modulus, Young's modulus, and Poisson's ratio, etc. Results indicated that the interlayer water content greatly impacted the mechanical properties of the materials. Interlayer water can enhance the compression properties of the overall system. When n=1, the compression properties of the material was best. When n=2, the capacity of the material to resist shear deformation was the worst and the system was most flexible. Interlayer water molecules greatly impacted the Young's modulus of the material while the impact on Poisson' s ratio was not obvious. Interlayer water molecules played a horizontal role of averaging the mechanical properties of the materials. The compression performance and the expansion of the material in the x-axis and y-axis tended to be the same.