为了准确求解交替方向隐式时域有限差分(Alternating Direction Implicit Finite-Difference Time-Domain,ADI-FDTD)方法实现理想电导体边界和理想磁导体边界的待求场分量系数,通过在获得该系数前应用理想导体边界条件,推导出了相应的...为了准确求解交替方向隐式时域有限差分(Alternating Direction Implicit Finite-Difference Time-Domain,ADI-FDTD)方法实现理想电导体边界和理想磁导体边界的待求场分量系数,通过在获得该系数前应用理想导体边界条件,推导出了相应的修正系数.计算了单个金属立方体和对称的两个金属立方体的双站雷达散射截面.结果表明:理想导体边界作为理想导体表面,采用修正系数的计算结果与时域有限差分(Finite-Difference Time-Domain,FDTD)方法计算结果更为吻合;理想导体边界作为截断计算空间对称面,采用修正系数的计算结果与ADI-FDTD方法计算结果相同,与理论推导结论一致.展开更多
采用分段线性电流密度递归卷积(P iecew ise L inear C u rren t D en sity R ecu rsive C onvo lu tion)方法将交替方向隐式时域有限差分方法(AD I-FDTD)推广应用于色散介质—等离子体中,得到了二维情况下等离子体中的迭代差分公式,为...采用分段线性电流密度递归卷积(P iecew ise L inear C u rren t D en sity R ecu rsive C onvo lu tion)方法将交替方向隐式时域有限差分方法(AD I-FDTD)推广应用于色散介质—等离子体中,得到了二维情况下等离子体中的迭代差分公式,为了验证该方法的有效性和可靠性,计算了等离子体涂敷导体圆柱的RC S和非均匀等离子体平板的反射系数,数据仿真结果表明,此算法与传统的FDTD相比,在计算结果吻合的情况下,存储量相当,计算效率更高,时间步长仅仅由计算精度来决定.展开更多
Square piles of reinforced concrete(RC)in marine environments are susceptible to chloride-inducedcorrosion.A novel reverse-seepage technique(RST)is applied to square piles to block the intrusion of chlorides.Thisresea...Square piles of reinforced concrete(RC)in marine environments are susceptible to chloride-inducedcorrosion.A novel reverse-seepage technique(RST)is applied to square piles to block the intrusion of chlorides.Thisresearch introduces a computational model designed to predict the lifespan of corrosion initiation in reinforced concretesquare piles when applied reverse-seepage pressure.The model considers the impacts of chloride binding and the tripletime-dependence property among the permeability,the corrected surface chloride concentration,and the diffusioncoefficient.The proposed numerical model is solved using the alternating direction implicit(ADI)approach,and itsaccuracy and reliability are evaluated by contrasting the computational outcomes with the analytical solution andexperimental results.Furthermore,the primary factors contributing to the corrosion of reinforced concrete square pilesare analyzed.The results indicate that applying RST can decrease the chloride penetration depth and prolong the lifespanof corrosion initiation in square piles.The water-cement ratio and reverse seepage pressure are the most influentialfactors.A water pressure of 0.4 MPa can double the life of concrete,and the durable life of concrete with a water-cementratio of 0.3 can reach 100 years.展开更多
文摘采用分段线性电流密度递归卷积(P iecew ise L inear C u rren t D en sity R ecu rsive C onvo lu tion)方法将交替方向隐式时域有限差分方法(AD I-FDTD)推广应用于色散介质—等离子体中,得到了二维情况下等离子体中的迭代差分公式,为了验证该方法的有效性和可靠性,计算了等离子体涂敷导体圆柱的RC S和非均匀等离子体平板的反射系数,数据仿真结果表明,此算法与传统的FDTD相比,在计算结果吻合的情况下,存储量相当,计算效率更高,时间步长仅仅由计算精度来决定.
基金Projects(52178371,52108355,52178321)supported by the National Natural Science Foundation of ChinaProject(202305)supported by the Research Project of Engineering Research Centre of Rock-Soil Drilling&Excavation and Protection,Ministry of Education,China。
文摘Square piles of reinforced concrete(RC)in marine environments are susceptible to chloride-inducedcorrosion.A novel reverse-seepage technique(RST)is applied to square piles to block the intrusion of chlorides.Thisresearch introduces a computational model designed to predict the lifespan of corrosion initiation in reinforced concretesquare piles when applied reverse-seepage pressure.The model considers the impacts of chloride binding and the tripletime-dependence property among the permeability,the corrected surface chloride concentration,and the diffusioncoefficient.The proposed numerical model is solved using the alternating direction implicit(ADI)approach,and itsaccuracy and reliability are evaluated by contrasting the computational outcomes with the analytical solution andexperimental results.Furthermore,the primary factors contributing to the corrosion of reinforced concrete square pilesare analyzed.The results indicate that applying RST can decrease the chloride penetration depth and prolong the lifespanof corrosion initiation in square piles.The water-cement ratio and reverse seepage pressure are the most influentialfactors.A water pressure of 0.4 MPa can double the life of concrete,and the durable life of concrete with a water-cementratio of 0.3 can reach 100 years.
