PREDICTION OF SOME PROPERTIES OF WARP KNITTED STRUCTURES BASED ON NUMERICAL SIMULATION

The warp knitted structures are used in wide area of different application, but because of their complexity, their engineering development is still based on the practical experience of the specialists and on the (n)trial and error"method. In the papers are reported analytical or numerical results for the prediction of the properties of the warp knitted samples, based on the machine data, pattern information and yarn properties only for small number of patterns. In order a general approach for solving such problems to be found, new numerical model of the geometry of the warp knitted structures was developed and implemented in specialized CAD software, presented last year. The current work presents an extension of the previous models and it allows the prediction of some important properties of the warp structures like yarn length in the sample, mass density, thickness, pore size etc. Under assumption, that the yarn cross section is circular, all these properties are calculated, using the yarn axis information from the simulations. To verify the results, all the predicted parameters are compared with the experimental ones. The comparison demonstrated a very good correlation for most of the structures. Certain differences are found for special structures, which change their form after the knitting process significantly, because of the stress relaxation