The effects of temperature and strain rate on yielding and springback behaviour of DP1000 dual phase steel

This study aims to investigate the effects of the temperature and strain rate on the yielding and springback behavior of DP1000 advanced high strength steel. For this purpose, material properties were defined using tensile tests at several temperatures (25 °C, 100 °C, 200 °C) and strain rates (0.0083 s -1 , 0.16 s -1 ). Yield loci were estimated by using Barlat-89 yield criteria. Springback behavior is specified by performing V bending tests. No significant effect was observed in the assessment of the effect of temperature on the yield locus and springback. Moreover, it was found that the increase in strain rate increased dramatically the yield locus and springback. © 2018 IOP Publishing Ltd

Comparison of drillability and abrasivity properties of rocks [Kayaçlari{dotless}n delinebilirlik ve aşi{dotless}ndi{dotless}ri{dotless}ci{dotless}li{dotless}k özelliklerinin karşi{dotless}laşti{dotless}ri{dotless}lmasi{dotless}]

Boren;DEMiR Export;et al;metso Expect results;Outotec;TMMOB Maden Muhendisleri Odasi23rd International Mining Congress and Exhibition of Turkey, IMCET 2013 -- 16 April 2013 through 19 April 2013 -- Antalya -- 105453Drillability is defined as the penetration rate of a drill bit into the rock. Abrasion is broken off by the tools during the excavation of rocks. Different types of rock formations have different abrasiveness and hardness properties and that is significantly affected excavatability and drillability in the mechanical excavation systems. Because, abrasive rocks and hard rocks lead to an increase of the cost excavation, decrease of the penetration rate and atrophy of the cutter in a short time. This study was carried out in Hopa-Borcka (Artvin) Cankurtaran Highway Tunnel. Rock samples were obtained from Cankurtaran Tunnel at the changing rock formations for the laboratory studies. The test samples were prepared at the appropriate size and quantity. Sievers J-miniature drill test (SJ) and the brittleness tests were carried out and for the drilling rate index values were calculated. Cerchar Abrasivity Index (CAI), Norway Abrasion Value (AV) and Bohme abrasion tests were carried out and for abrasiveness of rock properties. Uniaxial compressive strength, point load strength and Brazilian tensile strength tests were determined for the calculations mechanical properties of rock