Prediction of forming limit curve at fracture for sheet metal using new ductile fracture criterion

Dizaji, Shahram Abbasnejad
Darendeliler, Haluk
The application of ductile fracture criteria (DFCs) in numerical analysis of sheet metal forming processes can lead to the accurate determination of the fracture initiation. In this study, a new uncoupled ductile fracture criterion (DFC) has been developed which considers the effects of material parameters on the forming limit curves (FLCs) and can be easily implemented in the finite element codes. Two different constitutive models have been employed with the new DFC in order to evaluate the results obtained for fracture prediction. Various experimental tests have been utilized to validate the new criterion and its results are also compared with other well-known uncoupled DFCs. It is observed that the new criterion predicts the ductile fracture for all aluminum, steel and stainless steel materials better than the former criteria.


Investigation of the variations in microstructure and mechanical properties of dual-matrix ductile iron by Magnetic Barkhausen Noise analysis
Gür, Cemil Hakan; Erdogan, Mehmet (Informa UK Limited, 2008-01-01)
The variations in the microstructure and tensile properties of dual-matrix ductile irons have been investigated non-destructively by Magnetic Barkhausen Noise (MBN) method. Specimens have been intercritically austenitised at 795 degrees C and 815 degrees C for 20 minutes, and then oil-quenched to obtain different martensite volume fractions. Two specimens, namely as-cast and oil-quenched from 900 degrees C, were prepared for comparison purpose. To investigate the effect of tempering, some specimens were tem...
Assessing the Effects of Mechanical Preventive Measures on Alkali-Silica Reaction Expansion with Accelerated Mortar Bar Test
Musaoglu, Orhan; TURANLI, LUTFULLAH; Sarıtaş, Afşin (ASTM International, 2014-11-01)
This paper presents a modification to the apparatus of the mortar bar test of ASTM C490 in order to assess and compare the influence of mechanical preventive measures in reducing alkali-silica reaction (ASR) expansion in concrete with respect to the traditional measures. For this purpose, reinforced mortar specimens with or without pre-stressing force applied were examined and the effects of the reinforcement ratio and pre-stressing force on ASR-induced expansion and cracking were studied through the accele...
Impact essential work of fracture toughness of ABS/polyamide-6 blends compatibilized with olefin based copolymers
Ozkoc, Guralp; Bayram, Göknur; Bayramli, Erdal (Springer Science and Business Media LLC, 2008-04-01)
The impact fracture toughness of acrylonitrile-styrene-butadiene/polyamide-6 (ABS/PA6) blends compatibilized with 5% by weight carbon monoxide modified ethylene-n butyl acrylate-maleic anhydride (EnBACO-MAH) or ethylene-methyl acrylate-glycidyl methacrylate (EMA-GMA) copolymers were examined as a function of blend ratio by standard Charpy tests, Essential Work of Fracture (EWF) Methodology and fracture surface morphologies. The samples were first processed in twin-screw extruder and they were subsequently i...
A surface crack in a graded coating subjected to sliding frictional contact
Dağ, Serkan; GÜLER, MEHMET ALİ; Gulgec, Mufit (Elsevier BV, 2012-01-01)
This article presents an analytical method developed to conduct fracture analysis of functionally graded coatings that are under the effect of contact stresses. The geometric model considered comprises a functionally graded coating, which possesses a surface crack and is perfectly bonded to a homogeneous half-plane. A two-step solution procedure is put forward in which the contact and crack problems are treated separately. First, the graded coating is assumed to be in sliding frictional contact with a rigid...
Excessive damage increase in dual phase steels under high strain rates and temperatures
Cobanoglu, Merve; Ertan, Rasim K.; Şimşir, Caner; Efe, Mert (SAGE Publications, 2020-09-01)
Damage formation in dual phase steels is a complex process and it may be sensitive to the deformation conditions and mechanisms. In this study, the damage parameter is measured and compared under quasi-static and industrial forming conditions (temperatures: 25 vs 200, 300 degrees C and strain rates: 10(-3)vs 10 s(-1)) for DP590 and DP800 steels. Resonance frequency and ultrasonic sound velocity techniques are utilized for the measurements to test the effectiveness and validity of each technique. At a given ...
Citation Formats
S. A. Dizaji, H. Darendeliler, and B. KAFTANOĞLU, “Prediction of forming limit curve at fracture for sheet metal using new ductile fracture criterion,” EUROPEAN JOURNAL OF MECHANICS A-SOLIDS, pp. 255–265, 2018, Accessed: 00, 2020. [Online]. Available: