Лако-красочные материалы — производство

The full laminate was modeled in FE analysis using 2D solid elements with partitions having the properties of the corresponding plies. A thin layer of solid elements was inserted between the adherends, to simulate the presence of the adhesive layer. By gradually removing elements in the adhesive layer, the crack propagation was modeled. The variation of the BFS (indicated by red line in Figure 6) was extracted for each crack length. The BFS profile has a minimum negative peak and the corresponding position of that negative peak coincides with the crack position (Figure 7). In order to take into account the effect of the non-uniform strain field upon the response of the FBG sensors, the T-matix technique [48, 49] was also applied. Other causes of non­uniformity of the strain field can be the macrostructure of the composite material, particularly in the case of woven laminates [50]. In this case, size and position of sensors should be chosen according to the characteristics of the material’s macro-structure, in order to minimize these effects.