Characterization and simulation of electromagnetically induced preform resting (EIPR) process

Electromagnetically induced preform resting (EIPR) process is a new version of vacuum-assisted resin transfer molding (VARTM) process which allows manipulation of resin flow during the filling step. The EIPR process enhances the permeability of preform locally in case of undesirable flow front situations. This technique ensures the perfect filling despite the existence of permeability variation. To utilize the EIPR process in a better way, its comprehensive characterization to find the optimum value of key factors and filling simulation of it is necessary. Key factors of the EIPR process (i.e., amplitude, frequency of vibration) and permeability of preform as a material index are recognized as independent factors that must be considered to characterize the process. These factors are considered to establish a mathematical model for the permeability of preforms. Maximum and minimum values of the frequency and amplitude are determined based on the observations in acceptable composite material manufacturing and in-plane permeability characterization. Response surface methodology is used to model the permeability of EIPR process to find the optimum response values of the key factors for selected preforms. To assess the process numerically, EIPR process simulation with the optimum values is conducted on two case studies. These case studies involving two different permeability zones are designed in order for evaluation. In each case, a low permeability preform is employed in the middle of high permeability one to create an artificial problem. Simulation results demonstrate an acceptable accuracy.