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Electromagnetic tomography (EMT) is a non-invasive imaging technique capable of mapping the conductivity and permeability of an object. In EMT, eddy currents are induced in the object by the activation coils, and the receiving coils can measure the EMT voltages. When the activation frequency is significantly large, we can treat the metallic targets as electrically perfect conductors (EPCs). In this situation, a thin skin approximation is reasonable and this type of scattering problem can be effectively treated by the boundary element method (BEM) formulated through integration equations. In this study, we compute three-dimensional (3D) sensitivity matrix between the sensors due to an EPC perturbation. Efficiency improvement is achieved through the utility of scalar magnetic potential. Two EPC objects, one sphere and one cube shaped, are simulated. The results agree well with the H dot H formula. Overall, we conclude that BEM can be used to calculate the 3D sensitivity matrix of an EMT system efficiently. This method is a general one for any shaped objects while the H dot H solution is only capable of producing the response for a small ball. 相似文献
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重大工程一般都具有工程投资额大、技术含量和工程质量要求高、专业性强等特点。如何抓好重大工程施工阶段投资控制与管理,确保工程总投资控制在总盘子范围以内,是工程管理的一项重要内容。 相似文献
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深基坑开挖与锚杆支护FLAC3D数值模拟分析 总被引:1,自引:0,他引:1
运用FLAC3D软件对某市影视城及商办综合楼深基坑进行了开挖与支护的模拟.计算中采用摩尔-库伦弹塑性模型.通过计算得出深基坑的竖直位移、土体水平位移、锚杆的内力、土体应力应变分布,并与实测值进行了比较,最后采用强度折减法对基坑开挖和支护的稳定性进行了评价.可为工程设计与施工提供参考. 相似文献
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为研究低改高高速公路路桥过渡段加宽后路基的沉降特性,通过有限元建模分析,研究低改高高速公路路桥过渡段加宽的横、纵向断面沉降位移.结果表明:在横断面上,道路沉降主要集中在填筑期及工后5a内,地基表面竖向位移整体趋近于"盆"形,距离旧路基越远沉降越明显,拓宽侧工后沉降主要集中在2a内,占工后沉降的64%,在加宽路基中心附近... 相似文献
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