Modeling of spring-back in V-die bending process by using fuzzy learning back-propagation algorithm

Spring-back is one of the most sensitive features of sheet metal forming processes, which is due to the elastic recovery during unloading and leads to some geometric changes in the product. Three parameters which are most influential on spring-back in V-die bending process are sheet thickness, sheet orientation and punch tip radius. In this research, a new fuzzy learning back-propagation (FLBP) algorithm is proposed to predict the spring-back using the data generated based on experimental observations. The performance of the model in training and testing is compared with those of the constant learning rate back-propagation (CLBP) and the variable learning rate back-propagation (VLBP) algorithms. Then the best model with the minimum mean absolute error (MAE) is selected to predict the spring-back. The results indicated that the proposed FLBP algorithm has best performance in prediction of the spring-back with respect to the other algorithms.