Formability of Tailor Welded Blank (TWB) is an important parameter which limits this kind of blanks usage. A forming criterion for tailor welded blank is presented based on the analytical model in this research. This criterion suggests Limit Strength Ratio (LSR) and Limit Thickness Ratio (LTR) for forming limit of TWB. When thickness ratio or strength ratio in tailor welded blank is greater tha...

In order to optimize the hot forming process of tool steels, further improvement of flow stress prediction and additional knowledge on hot deformability, especially at lower and upper limits of the hot working range, are required. The hot working ranges for these steels are very narrow as a consequence of the role of alloying elements, which form carbides. Carbides improve tool steel’s hardenab...

Many efforts have been made to model the the hot deformation (dynamic recrystallization) flow curves of different materials. Phenomenological constitutive models, physical-based constitutive models and artificial neural network (ANN) models are the main methods used for this purpose. However, there is no report on the modeling of warm deformation (dynamic spheroidization) flow curves of any kin...

In this study, Buckling Limit of Strain (B.L.S.) is introduced as one of the most important limiting factors in cold roll forming process. B.L.S. is calculated by the finite element procedure. Then for two particular processes with existing analysis and experimental results, B.L.S. has been determined and evaluated. LUSAS 12.3 is used for finite element analysis. The results show that when buck...

The forming limit diagram (FLD) is probably the most common representation of sheet metal formability and can be defined as the locus of the principal planar strains where failure is most likely to occur. Low carbon steel sheets have many applications in industries, especially in automotive parts, therefore it is necessary to study the formability of these steel sheets. In this paper, FLDs, wer...

Bacterial detection plays an important role in protecting public health and safety, and thus, substantial research efforts have been directed at developing bacterial sensing methods that are sensitive, specific, inexpensive, and easy to use. We have recently reported a novel "mix-and-read" assay where a fluorogenic DNAzyme probe was used to detect model bacterium E. coli. In this work, we carri...

In sheet metal forming processes with complex strain paths, a part is subjected to large plastic deformation. This severe plastic deformation leads to high plastic strain localization zones and subsequent accumulation of those strains. Then internal and superficial micro-defects and in other words ductile damage is created. This damage causes quality problems such as fracture. Therefore, design...