Dynamic Compression Behavior Of AISI 4340 Steel Under Various Strain Rates And Temperatures

Hakan Hafızoğlu

Makale detayları

Dynamic Compression Behavior Of AISI 4340 Steel Under Various Strain Rates And Temperatures

Yazarlar:

Hakan Hafızoğlu

Yayıncı:

Kirikkale University

Ana Başlıklar:

Numerical Methods in Mechanical Engineering | Material Design and Behaviors | Numerical Modelling and Mechanical Characterisation

Dergi:

International Journal of Engineering Research and Development Vol.16 Issue 2, pp.707-720

Belge Tipi:

Makale

Yayın Tarihi:

6/2024

Belge Dili:

İngilizce

Document ID (Org No.):

2001314831

pISSN:

1308-5506

Anahtar kelimeler:

Özet:

 In this study, dynamic compression behavior of AISI 4340 steel alloy was investigated with split-Hopkinson and Taylor impact tests and numerical studies. Dynamic compression tests at strain rates of 725, 1500, 2000 s-1 at room temperature and at high temperatures of 150 and 250 C were done using split-Hopkinson pressure bar. Taylor impact tests with the impact velocities of 245, 324 and 336 ms-1 were performed with cylindirical specimens to observe dynamic deformation behavior at impact conditions. Numerical studies using Ls-Dyna 3D finite element method were conducted to investigate temperature and stress distribution of specimens during Taylor impact tests. Experimental results revealed that as strain rate increased, yield and ultimate compressive strengths and total strains increased at room temperature at dynamic compression tests. At elevated test conditions, both strengths decreased and total strains increased due to softening effect. Taylor impact test results showed that all the specimens exhibited mushroomed deformation and increase of impact velocity led to shear crack and fracture at the end of deformation process. Numerical results indicates that highest temperatures were obtained at the impact surfaces for three impact velocities. In addition, the increase of impact velocity enhanced the stress distribution at deformed regions near impact surfaces.

 In this study, dynamic compression behavior of AISI 4340 steel alloy was investigated with split-Hopkinson and Taylor impact tests and numerical studies. Dynamic compression tests at strain rates of 725, 1500, 2000 s-1 at room temperature and at high temperatures of 150 and 250 C were done using split-Hopkinson pressure bar. Taylor impact tests with the impact velocities of 245, 324 and 336 ms-1 were performed with cylindirical specimens to observe dynamic deformation behavior at impact conditions. Numerical studies using Ls-Dyna 3D finite element method were conducted to investigate temperature and stress distribution of specimens during Taylor impact tests. Experimental results revealed that as strain rate increased, yield and ultimate compressive strengths and total strains increased at room temperature at dynamic compression tests. At elevated test conditions, both strengths decreased and total strains increased due to softening effect. Taylor impact test results showed that all the specimens exhibited mushroomed deformation and increase of impact velocity led to shear crack and fracture at the end of deformation process. Numerical results indicates that highest temperatures were obtained at the impact surfaces for three impact velocities. In addition, the increase of impact velocity enhanced the stress distribution at deformed regions near impact surfaces.

 In this study, dynamic compression behavior of AISI 4340 steel alloy was investigated with split-Hopkinson and Taylor impact tests and numerical studies. Dynamic compression tests at strain rates of 725, 1500, 2000 s-1 at room temperature and at high temperatures of 150 and 250 C were done using split-Hopkinson pressure bar. Taylor impact tests with the impact velocities of 245, 324 and 336 ms-1 were performed with cylindirical specimens to observe dynamic deformation behavior at impact conditions. Numerical studies using Ls-Dyna 3D finite element method were conducted to investigate temperature and stress distribution of specimens during Taylor impact tests. Experimental results revealed that as strain rate increased, yield and ultimate compressive strengths and total strains increased at room temperature at dynamic compression tests. At elevated test conditions, both strengths decreased and total strains increased due to softening effect. Taylor impact test results showed that all the specimens exhibited mushroomed deformation and increase of impact velocity led to shear crack and fracture at the end of deformation process. Numerical results indicates that highest temperatures were obtained at the impact surfaces for three impact velocities. In addition, the increase of impact velocity enhanced the stress distribution at deformed regions near impact surfaces.

 Bu çalışmada, AISI 4340 çelik alaşımının dinamik basma davranışı ayrık-Hopkinson ve Taylor çarpma testleri ve nümerik çalışmalarla incelenmiştir. Ayrık-Hopkinson basınç barı kullanılarak oda sıcaklığında 725, 1500, 2000 s-1 gerinme hızlarında ve 150 ve 250 C yüksek sıcaklıklarında dinamik basma testleri yapılmıştır. Çarpma koşullarında dinamik deformasyon davranışını gözlemlemek için 245, 324 ve 336 ms-1 çarpma hızlarında Taylor çarpma testleri icra edilmiştir. Taylor çarpma testlerinde numunelerdeki gerilme ve sıcaklık dağılımının incelenmesi için Ls-Dyna 3D sonlu elemanlar yöntemi kullanılarak numerik çalışmalar yapılmıştır. Deneysel sonuçlar oda sıcaklığında yapılan dinamik basma testlerinde gerinme hızının artışı ile akma ve en fazla basma dayanımının ve toplam gerinmenin arttığını göstermiştir. Yüksek sıcaklık koşullarında yumuşama etkisi dolayısıyla her iki dayanım da düşmüş ve toplam gerinmeler artmıştır. Taylor çarpma test sonuçları tüm numunelerin mantarlanma deformasyonuna uğradığını ve çarpma hızı artışının kesme çatlakları ve deformasyon sürecinin sonunda kırılmaya neden olduğunu göstermiştir. Nümerik sonuçlar en yüksek sıcaklıkların üç çarpma hızı için de çarpma yüzeylerinde bulunduğunu göstermiştir. Ek olarak, çarpma hızının artışı çarpma yüzeylerine yakın deforme olmuş bölgelerde gerilme dağılımını artırmıştır.

Makale detayları

Dynamic Compression Behavior Of AISI 4340 Steel Under Various Strain Rates And Temperatures

Yazarlar:

Hakan Hafızoğlu

Yayıncı:

Kirikkale University

Ana Başlıklar:

Numerical Methods in Mechanical Engineering | Material Design and Behaviors | Numerical Modelling and Mechanical Characterisation

Dergi:

International Journal of Engineering Research and Development Vol.16 Issue 2, pp.707-720

Belge Tipi:

Makale

Yayın Tarihi:

6/2024

Belge Dili:

İngilizce

Document ID (Org No.):

2001314831

pISSN:

1308-5506

Taylor impact test

split-Hopkinson pressure bar

AISI 4340 steelTaylor çarpma testi

ayrık-Hopkinson basıç barı

AISI 4340 çeliği

Sayı

Makale detayları

Dynamic Compression Behavior Of AISI 4340 Steel Under Various Strain Rates And Temperatures

Yazarlar: Hakan Hafızoğlu

Yayıncı: Kirikkale University

Ana Başlıklar: Numerical Methods in Mechanical Engineering | Material Design and Behaviors | Numerical Modelling and Mechanical Characterisation

Dergi: International Journal of Engineering Research and Development Vol.16 Issue 2, pp.707-720

Belge Tipi: Makale

Yayın Tarihi: 6/2024

Belge Dili: İngilizce

Document ID (Org No.): 2001314831

pISSN: 1308-5506

Taylor impact test

split-Hopkinson pressure bar

AISI 4340 steelTaylor çarpma testi

ayrık-Hopkinson basıç barı

AISI 4340 çeliği

Sayı

Yazarlar:

Hakan Hafızoğlu

Yayıncı:

Kirikkale University

Ana Başlıklar:

Numerical Methods in Mechanical Engineering | Material Design and Behaviors | Numerical Modelling and Mechanical Characterisation

Dergi:

International Journal of Engineering Research and Development Vol.16 Issue 2, pp.707-720

Belge Tipi:

Makale

Yayın Tarihi:

6/2024

Belge Dili:

İngilizce

Document ID (Org No.):

2001314831

pISSN:

1308-5506