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Study On Electromagnetic Wave Absorbing Concrete And Its Key Technologies

Posted on:2011-08-31Degree:DoctorType:Dissertation
Country:ChinaCandidate:S M DingFull Text:PDF
GTID:1112330338450085Subject:Radio Physics
Abstract/Summary:PDF Full Text Request
Under the informationization warfare condition, for antagonizing serious threaten caused by electromagnetic pulse weapon and radar scouting technique to the survival of the protective engineering, overcoming the existing problems in the field of EMP protection, the new electromagnetic protective material technique is studied. This paper is author's production in the course of guiding task. The breakthrough and innovative achievements in the field of the basic theory of radar absorbing materials, testing techniques and development of electromagnetic absorbing concrete have obtained. The specific thesis research content and main achievements are as follows:1. Detailed analysis of the problems existing in the stealth and electromagnetic pulse protection of the protective engineering is worked. The solutions and measures are proposed. The idea of this study is established.2. The impedance matching condition of macro electromagnetic parameters of materials is deduced from the Maxwell equation of the plane electromagnetic wave pread in the absorbing materials, a new impedance matching condition on the electromagnetic absorbing material is brought foreword. The impedance matching condition indicates conditions of achieving impedance matching, provides the basis for the development of high-performance absorbing material.3. The electromagnetic fields finite difference time domain method (FDTD) separately combined with genetic algorithm (GA) and particle swarm optimization (PSO) is first applicated to study the relationship of the equivalent electromagnetic parameters between a mixed medium and compositions materials. The calculation method of equivalent electromagnetic parameters of mixed medium is obtained, and has higher accuracy and wider application spectrum compared with the traditional formula and empirical formula. On this basis, a computer-aided design optimization software is developed to computer-aided design for the purpose of absorbing material.4. A set of the suitable materials test systems for electromagnetic shielding, reflection characteristics, electromagnetic parameters are developed such as radar absorbing materials bow reflectivity testing system, rectangular coaxial test system, waveguide test system and coaxial probe with flange test system. The respectively testing methods were studied.5. A new free-space method of measurement of electromagnetic parameters by the resonant characteristics of material reflectance in the free space is proposed, which is rich and make a breakthrough at test method of non-magnetic material electromagnetic parameters.6. The process mechanism of electromagnetic wave absorbing concrete is studied and revealed. Further, the improving the material properties of the methods and measures is proposed. Thus, the principles and methods selected low-cost, high-performance electromagnetic wave absorbing and shielding raw is also given. And base on engineering practice, a method of quick selecting raw is given.7. It is developed the electromagnetic wave absorbing concrete with integration of structure and function, such as electromagnetic shielding, radar stealth and building structural material. It can play important role in the whole electromagnetic pulse protection, and improving utilization of underground space, and reducing symptoms of exposure to the radar surveillance, which has significant military, economic and social benefit.8. During materials development, the detailed factors impacted material electromagnetic wave absorbing properties and strength are studied. And by the use of coarse aggregate of electromagnetic absorbing mineral materials, the technical difficulties in concordance between electromagnetic properties and mechanical properties of electromagnetic wave absorbing concrete are successfully resolved. The technical difficulty of common Electromagnetic shielding materials with high reflectivity is successfully soluted by material preparation and surface molding technology. The technical difficulty of electromagnetic shielding under the full spectrum range of concrete-like materials is solved by composite technologies and materials design. The problems concerned in the practical engineering such as corrosion resistance, long-term stability, durability and material security issues of this materials are effective soluted, so that the electromagnetic wave absorbing concrete has a life as same as ordinary concrete's and stable performance, using unrestricted. The problem of construction technology of this material is studied and solved to make it with the same process of ordinary concrete and to reduce costs.9. A synthesis benefits analysis among electromagnetic wave absorbing concrete and carbon fiber reinforced concrete, carbon powder concrete and so on indicates this material have advantages in the field of its performance, synthesis benefits and other aspects.
Keywords/Search Tags:Impedance matching theory, Electromagnetic parameters, Electromagnetic wave absorbing concrete, Electromagnetic shielding, Military and economic benefits
PDF Full Text Request
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