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论文类型：会议论文

发表时间：2007-03-19

收录刊物：EI、CPCI-S、Scopus

卷号：6530

关键字：OFBG sensor; mono-scalar; isotropic; damage; constitutive model; strain interface transferring; error rate; microcrack; inclusion; void

摘要：This paper presents the interface transferring mechanism and error modification of the Optical Fiber Bragg Grating (OFBG) sensors based on the mono-scalar isotropic damage constitutive model. The OFBG sensor is made up of optical fiber and encapsulated materials which include protective coating, adhesive layer et al. The accuracy of OFBG sensor is highly dependent on the physical and mechanical properties of the optical fiber and encapsulated materials. The encapsulated materials were regarded as scatheless continuum in the prevenient researches and the elastic modulus, for example, the Young's modulus (E) or shear modulus (G), was keeping constant from the beginning to the end of transformations. However, there is lots of damage, such as microcracks, inclusions and voids, in the encapsulated materials. And these inicro-defects can become cores, expand and joint up with together which induce the gradual bad in the materials. Hence, the modulus (E and G) is no longer assumed as a constant but as a variable with the damage. So the mono-scalar isotropic damage model (damage modulus D) is employed to describe the shear constitutive equation of the encapsulated materials along the optical fiber axes. The general expression of multilayer interface strain transferring mechanism of OFBG sensor is given based on the isotropic damage theory. And the error rate and error modification coefficient of OFBG sensor are obtained under the defining of average strains. The results indicate that the damage of encapsulated materials affects the interface strain transferring property of the OFBG sensor.