Determination of LDR in deep drawing using reduced number of blanks

Abstract

Indeed, deep drawing is one of the important sheet metal forming process, widely used in production of cup shaped articles having applications in different engineering and domestic fields such as aerospace, automobile, beverage, kitchenware etc. It is essential to determine the quality characteristics of the process for minimization of rejections as well as cost involved in it. LDR is one such quality characteristic essential to evaluate thoroughly with reduced number of steps in deep drawing. Here, the LDR is determined by means of experimental and simulation method by using the concept of “ punch force is proportional to blank diameter up to limiting drawing ratio” and remains constant over the LDR for all oversized blanks resulting in failure. In this research paper, an attempt has been made to establish a standard and quick method for “determination of LDR”. The LDR tests have been conducted with the use of only three blanks of different sizes; i.e., two of undersize and one blank of oversize. The LDR found through experiments and simulation are in good agreement with only 5.4% variation and this variation may be due to variation in lubrication conditions among the experimental and simulation methods.