Determination of Johnson Cook Strength and Failure Parameters of EN-GJS-400 Spheroidal Graphite Cast Iron

Year 2024, Volume: 40 Issue: 2, 254 - 269, 31.08.2024

Burak Özcan , Ulvi Şeker

Abstract

In this study, to investigate the mechanical behavior of EN-GJS-400 nodular cast iron material, quasi-static tensile tests were conducted at room temperature and at 300°C, 500°C, and 700°C, along with compression tests at room temperature. To examine the behavior at high deformation rates, Split Hopkinson tests were carried out at four different strain rates, reaching up to approximately 4500/s. To reveal the damage behavior of the materials, tensile tests were conducted with four different notches (R=1.25, 2.5, 5, 10mm). Microstructure experiments and spectral analyses of the materials were performed. Based on the data obtained from the experiments, Johnson-Cook (J-C) material and damage model parameters were calculated. The calculated J-C material and damage parameters were defined in the Abaqus finite element software, and virtual tensile tests were conducted and compared with the actual test data.

Keywords

EN-GJS-400, Johnson-Cook, Split Hopkinson, Finite Element Analysis

EN-GJS-400 Küresel Grafitli Dökme Demir Malzemenin Johnson-Cook Malzeme ve Hasar Parametrelerinin Belirlenmesi

Abstract

Bu çalışma kapsamında EN-GJS-400 küresel grafitli dökme demir malzemenin mekanik davranışlarını incelemek için oda koşullarında ve 300, 500 ve 700° derece sıcaklıklarda yarı statik çekme ve oda koşullarında basma deneyleri gerçekleştirilmiştir. Yüksek şekil değiştirme hızlarında davranışlarını incelemek için dört farklı şekil değiştirme hızında yaklaşık, maksimum 5500/s gerinim hızına kadar Split Hopkinson testleri gerçekleştirilmiştir. Malzemelerin hasar davranışlarını ortaya koyabilmek için 4 farklı çentikte (R=1.25, 2.5, 5, 10mm) çekme deneyleri gerçekleştirilmiştir. Malzemelerin mikro yapı deneyleri ve spektral analizleri gerçekleştirilmiştir. Deneylerde elde edilen veriler doğrultusunda Johnson-Cook(J-C) malzeme ve hasar model parametreleri hesaplanmıştır. Hesaplanan JC malzeme ve hasar parametreleri Abaqus sonlu elemanlar yazılımında tanımlanarak çekme testleri sanal ortamda gerçekleştirilmiş ve gerçek test verileriyle karşılaştırılmıştır.

Keywords

EN-GJS-400, Johnson-Cook, Split Hopkinson, Sonlu Elemanlar Analizi

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