基于三角面元法的常磁性复杂形体磁异常正演
|
摘要
近源磁观测中,需要对场源形态和姿态进行精细的刻画,这对磁异常正演计算提出了新要求。针对这一问题,在常磁性条件下基于表面磁荷积分原理,探索了复杂形体高精度三角面元法磁异常正演模拟方法技术。针对工程磁探测中常见的复杂工程构件,借助有限元软件平台,绘制以三通管道、未爆弹为代表的复杂模型,并使用有限元计算模块的前期处理功能,对模型进行自动不规则三角网格剖分。编写平台间的数据接口软件,通过数据接口导出三角网格数据,并进行三角面元法磁异常正演。模型计算结果表明,近源观测时用简化模型代替复杂模型进行磁异常正反演可能会产生较大误差。
Aiming at near-source observation, under the condition of constant magnetism, a fast, accurate magnetic forward modeling method based on surface element integration theory is proposed to meet the new demand of precisely portraying sources′ shape and position in the magnetic forward modeling. To solve the high-precision forward modeling of complex model encountered in engineering magnetic survey, with the help of the finite element platform, common complex engineering components like Tee pipe and UXO(unexploded ordnance) were built. The pre-processing modulus of the finite element calculation give rise to the automatic building of irregular triangular mesh. Meanwhile, import and export channel is built to form a bi-directional channel between two platforms. The irregular triangular mesh data are used to calculate the magnetic anomaly of the complex engineering components. The model tests show that using simplified model to replace complex model can lead to great error in calculation of magnetic forward modeling and inversion.
Aiming at near-source observation, under the condition of constant magnetism, a fast, accurate magnetic forward modeling method based on surface element integration theory is proposed to meet the new demand of precisely portraying sources′ shape and position in the magnetic forward modeling. To solve the high-precision forward modeling of complex model encountered in engineering magnetic survey, with the help of the finite element platform, common complex engineering components like Tee pipe and UXO(unexploded ordnance) were built. The pre-processing modulus of the finite element calculation give rise to the automatic building of irregular triangular mesh. Meanwhile, import and export channel is built to form a bi-directional channel between two platforms. The irregular triangular mesh data are used to calculate the magnetic anomaly of the complex engineering components. The model tests show that using simplified model to replace complex model can lead to great error in calculation of magnetic forward modeling and inversion.
引文
[1] 葛健,陆承达,董浩斌,等.基于Overhauser传感器的近地表UXO磁梯度法探测技术[J]. 仪器仪表学报,2015,36(5):961-974.
[2] Sinex D B.Advancing the state of the art of UXO discrimination for total-field magnetic data[D].Golden:Colorado School of Mines,2006.
[3] Sanchez V,Li Y G,Nabighian M N,et al.Numerical modeling of higher order magnetic moments in UXO discrimination[J].IEEE Transaction on Geoscience and Remote sensing,2008,46(9):2 568-2 583.
[4] Furness P.Modeling magnetic fields due to steel drum accumulations[J].Geophysical Prospecting,2007,55(5):737-748.
[5] Marchetti M,Sapia V, Settimi A.Magnetic anomalies of steel drums:a review of the literature and research results of the INGV[J].Annals of Geophysics,2013,56(1):1 415-1 422.
[6] 吴健生,蒋婉聪.多姿态具磁性未爆弹磁异常快速正演[J].同济大学学报(自然科学版),2018,46(5):687-694.
[7] 施国良,张国雄.宏观场论[M].武汉:中国地质大学出版社,1987.
[8] 管志宁.地磁场与磁力勘探[M].北京:地质出版社,2005.
[9] 纪兵兵,陈金瓶.ANSYS ICEM CFD网格划分技术实例详解[M].北京:中国水利水电出版社,2012.
[2] Sinex D B.Advancing the state of the art of UXO discrimination for total-field magnetic data[D].Golden:Colorado School of Mines,2006.
[3] Sanchez V,Li Y G,Nabighian M N,et al.Numerical modeling of higher order magnetic moments in UXO discrimination[J].IEEE Transaction on Geoscience and Remote sensing,2008,46(9):2 568-2 583.
[4] Furness P.Modeling magnetic fields due to steel drum accumulations[J].Geophysical Prospecting,2007,55(5):737-748.
[5] Marchetti M,Sapia V, Settimi A.Magnetic anomalies of steel drums:a review of the literature and research results of the INGV[J].Annals of Geophysics,2013,56(1):1 415-1 422.
[6] 吴健生,蒋婉聪.多姿态具磁性未爆弹磁异常快速正演[J].同济大学学报(自然科学版),2018,46(5):687-694.
[7] 施国良,张国雄.宏观场论[M].武汉:中国地质大学出版社,1987.
[8] 管志宁.地磁场与磁力勘探[M].北京:地质出版社,2005.
[9] 纪兵兵,陈金瓶.ANSYS ICEM CFD网格划分技术实例详解[M].北京:中国水利水电出版社,2012.