MODELING DEFORMATION PROCESSES IN FLEXIBLE WOVEN COMPOSITES. PART 1. STRUCTURAL MODELS

Abstract

Research papers on modeling deformation processes in flexible woven composites have been analytically reviewed; it has been concluded that the available models describing the behavior of woven composites are mostly applicable to 'rigid' composites based on epoxy, concrete or ceramics. Most models do not account for irreversible deformations and change of form of the internal structure of the material taking place in the process of deformation. The main attention in the theoretical and experimental studies on woven composites under static external loading is given to analyzing uniaxial tension. The available models of flexible woven composites determine only individual mechanical characteristics of the material, such as initial elasticity modulus, strength, etc., without accounting for straightening of the filaments in the process of tension. An approach to developing structural models of the behavior of flexible woven composites is presented, which is based on modeling deformation processes of the internal material structure. Using the present approach, three structural models have been developed: a laminate model, a model of elementary periodic cell and a model of frame analogy. The main idea of the laminate model is in discretizing the internal structure of the reinforcing tissue and constructing a laminated equivalent of the initial material. The model of elementary periodical cell is based on a detailed description of the internal structure of the material. In the frame analogy model, filaments of the reinforcing tissue are represented as plane frames, thus accounting for the changes of the geometrical structure and the interaction with cross-interwoven filaments. The scope of the adequate application of the introduced models is determined.

Keywords: flexible woven composite material, periodic element, change of form, irreversible deformations, structural model, finite element method.