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The pultrusion of large-diameter glass fiber reinforced epoxy rods at high pulling speed is often accompanied by the formation of cracks at the surface of a profile, leading to product rejection. In this study, we investigate the causes of crack formation based on numerical simulations of manufacturing process mechanics, including the temperature distribution, degree of polymerization, and residual stresses. Based on the built model, we solve the problem of temperature condition optimization for maximizing pulling speed. The results show that up to 27% increases in pulling speed are possible provided that the following conditions are met: thermal destruction of the material is avoided; a profile is cooled sufficiently quickly before cut-off; a high degree of polymerization is achieved in a final product; and there are no cracks in a profile.

The calculation of proppant pack properties under load is useful to determine the optimal material parameters and grain size distribution. A simple, yet effective model for simulation of both mechanical deformation and permeability of the pack in specific case of polymeric proppant is presented. The mechanical deformation modeling is similar to the discrete elements method, where permeability is calculated with the lattice Boltzmann method. The simulation imitates the standard procedure for measuring the conductivity of a proppant. Permeabilities for different loads and different grain size distributions are obtained.