Papers by Author: R. Ganesh Narayanan

Abstract: The main aim of the work is to analyze the influence of welding speed and tool rotation speed on the forming behavior of FSW blanks. The FSW blanks are made of 6061 Al sheet of 2.1 mm thickness. The welded sheets are made at two different optimized levels of welding speed (90 and 100mm/min) and tool rotation speed (1300 and 1400 rpm). The effect of FSW parameters on the forming limit curve (FLC) and thickness distribution was analyzed by performing limit dome height (LDH) tests at few pre-defined stretching strain paths. It is observed that FSW blanks exhibit more formability as compared to un-welded sheets. The forming limit is found to improve with increase in tool rotation speed and it decreases with increase in welding speed. An attempt has been made to relate the thinning gradient developed during necking with the forming limit at different welding conditions.

Abstract: The forming behavior of Tailor Welded Blanks (TWB) are greatly influenced by blank conditions like thickness ratio, strength ratio, weld conditions like weld orientation, weld location, and weld properties. Designers will be greatly benefited if an ‘Expert system’ is available that can deliver forming behavior of TWB for varied weld and blank conditions. This work primarily aims at developing an expert system based on Artificial Neural Network (ANN) to predict the tensile behavior of TWBs made of DP 590 Steel grade base material. ANN models are developed based on full factorial and L27 orthogonal array design of experiments method and the results are compared. Through out the work, PAM STAMP 2G® finite element (FE) code is used to simulate the tensile behavior. The strain hardening exponent ‘n’ and strength co-efficient ‘K’ are predicted and used to train the ANNs. The results obtained from expert system/ANN models are validated by comparing them with the results obtained from FE simulations for chosen intermediate levels. The results are encouraging with acceptable prediction errors.