Three Dimensional Finite Element Analysis Of Electromagnetic Shielding Of Reinforced Concrete Walls Using Edge-elements

The electromagnetic shielding is an important aspect of modern wireless communication.It is used to insure the security of communication and prevent the pollution of electromagnetism.Now it is widely applied in the field of military, business and industry control fields. Most ofthe modern buildings are constructed by concrete or reinforced concrete, so the study on theelectromagnetic shielding of the concrete walls has a very important value of practicality. Tostudy short-range wireless communications such as IrDA, 802.11, BlueTooth, ZigBee, UWB,RFID, we must know how reinforced walls affect electromagnetic propagation.The paper used the 3D edge element-perfectly matched layer method (FEM-PML) toanalyze the electromagnetic shielding effectiveness (SE) of concrete walls with the frequence of900MHz and 1800MHz based on the results of the previous research from. Floquet's theoremwas used to reduce the calculation of biperiodic structure reinforce concrete wall. Thepropagation influences of the parameters of reinforced concrete wall such as steel diameter,weld point, length of meshes, thickness of the walls and changes of the surface, layers of themeshes and the medium materials were studied. Meanwhile the values of electric field in thepropagation direction into the reinforced concrete walls were given out. The paper studied theelectromagnetic wave of different frequence passing through the walls. It also simulated theeffect of electromagnetic shielding caused by the changes of the layers of reinforcing wire, thediameter of the wire, the size of the gridding, the characteristics of the concrete(with mixedmaterials, humidity, shapes etc). The paper also made some compares of the former studies andthe results showed that we can change the shapes and parameters of the concrete walls to getdifferent shielding effectiveness. The results are useful for the study of indoor wirelesscommunication and the electromagnetic shielding of concrete architectures. At last the paperimproved the 3D edge element method software EMAP4 on the pre-processing andvisualization of the results.