Modeling a Stressed State in the Vicinity of an Optical Fiber Embedded in a Polymer Composite Material with Allowance for the Structural Features of the Composite

摘要

This work is concerned with two important scientific areas: mechanics of polymer composite materials (PCMs) and the development of new methods for diagnostics and monitoring of the mechanical state of a structure based on fiber-optic sensors. The nomenclature and the range of application of PCMs are expanding very rapidly. Currently, the percentage of the use of composite materials is one of the indicators of the competitiveness of the corresponding products. At the same time, theoretical results concerning the assessment of the workability of PCM structures do not always keep up with the requests of designers developing new products. Therefore, model assessments should be complemented with modern monitoring systems. Fiber-optic sensors offer opportunities for creating new monitoring scenarios. One of them is associated with the use of sensors embedded in a PCM. This gives a new kind of smart material, in which the PCM, along with its basic functions, provides information on its parameters: temperature, strain, etc. The development of this class of smart materials requires solving a number of problems. One of them, which is the subject of the present work, is the evaluation by methods of mathematical modeling of changes in the stiffness and strength characteristics of PCM products due to the integration of fiber-optical sensors into the material. In contrast to the known works, the developed computational models take into account the layered structure of a PCM, the types of layer stacking, the arrangement of layers and optical fiber, the presence of a technological defect in the form of a resin pocket with the elimination of points of stress singularity that are present in the known computational schemes. The model proposed in this work can be used to estimate the stress concentration in the layers of the composite material adjacent to the optical fiber.