Showing papers by "Taylan Altan published in 2016"
TL;DR: In this paper, an analytical model was developed to predict the springback in air-bending of AHSS, considering the special properties of these materials, and a computer code which was developed based on classical bending theory was updated based on the new model.
64 citations
TL;DR: In this article, the effect of Ram speed and stroking rate (stroke per minutes) upon temperature increase in real production-like operation in single and multiple stroke operations has been investigated.
Abstract: In forming of AHSS the temperature increase at die/sheet interface affects the performance of lubricants and die wear. This study demonstrates that Finite Element (FE) analysis, using commercially available software, can be used to estimate temperature increase in single as well as in multiple stroke operations. To obtain a reliable numerical process design, the knowledge of the thermomechanical properties of the sheet as well as the tools is essential. Using U-channel drawing the FE model has been validated by comparing predictions with experimental results. The effect of ram speed and stroking rate (stroke per minutes) upon temperature increase in real production-like operation have been investigated. Deep drawing of CP800 and DP590 blanks in a servo drive press, using an industrial scale die, has been studied. Thinning distribution and temperatures in the drawn part have been investigated in single and multiple forming operations. It is found that temperatures may reach several hundreds degrees and affect the coefficient of friction (COF). The values of COF under production-like conditions were compared to that obtained from laboratory experiments. This study illustrates that in forming AHSS, a) the temperature increase at the die/ sheet interface is relatively high and should be considered in process design stage b) the lubricant performance is significantly affected by the ram speed and sheet/die interface temperature during deformation.
6 citations