Research on the influence of process parameters in multi-point forming of complex curved thick blades

As a key component in energy conversion equipment, blades meet strict requirements for geometric accuracy and surface quality. To balance production efficiency and cost, a novel process has been proposed for forming complex curved thick blades using multi-point dies. In this study, the room-temperature flow stress curve of the blade material FV520B was obtained through experiments and corrected for friction. A finite element model was developed to capture the entire process of blade forming and springback. A novel program was developed to enable the precise extraction and display of dimplings during post-processing. A single-factor analysis was conducted to investigate the influence of pad material, pad thickness, plate thickness, punch size and forming speed on the maximum dimpling depth, total number of dimplings, maximum load and root mean square error deviation after springback in multi-point forming. The results indicate that the four factors exert varying degrees of influence on the response except forming speed. Second-order models predicting different responses based on pad material, pad thickness and punch size were established using response surface methodology, and optimal process parameters were obtained. Finite element analysis and actual process experiments were conducted using the optimal process parameters, and the results of the two were compared. The surface of the formed blade in the process experiments showed no significant dimplings. The maximum load differed by 2.65% between the two methods, and the root mean square error deviation after springback differed by 9.08%, confirming the accuracy and reliability of the finite element simulation.