A new model to simulate crack arrest behavior in steel plates used for naval structures

2016 ◽  
Author(s):  
Fuminori Yanagimoto ◽  
Katsuyuki Suzuki ◽  
Kazuki Shibanuma ◽  
Shuji Aihara
Keyword(s):  
Crack Arrest ◽  
Steel Plates ◽  
New Model ◽  
Naval Structures

Study on Unstable Brittle Crack Arrest Toughness of Extremely-Low Carbon Bainitic Steel Plates

Materials ◽  
2004 ◽  
Author(s):  
Tsunehisa Handa ◽  
Takahiro Kubo ◽  
Keniti Amano ◽  
Mitsuhiro Okatsu ◽  
Kazunori Miyamoto ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Cross Section ◽  
Test Piece ◽  
Main Crack ◽  
Crack Arrest ◽  
Steel Plates ◽  
Bainitic Steel ◽  
Low Carbon ◽  
Brittle Crack ◽  
Arrest Toughness

The extremely-low carbon bainitic steel (ELCB steel) is a high strength steel with about 0.02 mass% or less carbon. In this research, unstable brittle crack arrest toughness of ELCB steel plates was investigated by temperature-gradient ESSO tests, compared with that of conventional TMCP steel plates. Both of ELCB and TMCP steel plates without pre-straining had sufficient crack-arrest toughness at 0°C. After 10% prestraining, the TMCP steel plate had not sufficient crack-arrest toughness at 0 °C . The ELCB steel plates, however, maintained high crack arrest toughness at 0°C. even after 10% pre-straining. ELCB steel were also different from TMCP steels in the correlation between transition temperature of crack arrest toughness and fracture appearance transition temperature (vTrs) obtained by Charpy impact test. When the vTrs of an ELCB steel and that of a TMCP steel were the same value, crack arrest toughness of an ELCB steel was higher than that of a TMCP steel. In the cross section of the ESSO test piece of the ELCB steels, many sub-cracks and micro-crack branching were observed. However, in the cross section of the ESSO test piece of the conventional TMCP steels, there were few subcracks and branching. Initiation of sub-cracks and branching around the main crack tip reduces the stress intensity factor of the main crack. It was considered that the above features of the ELCB steel were caused by initiation of sub-cracks and branching at the tip of the main brittle crack.

A new model for calculating the elastic local buckling stress of steel plates in square CFST columns

2022 ◽  
Vol 171 ◽  
pp. 108756
Author(s):  
Yue-Ling Long ◽  
Lin Zeng ◽  
Leroy Gardner ◽  
M. Ahmer Wadee
Keyword(s):  
Local Buckling ◽  
Steel Plates ◽  
New Model ◽  
Buckling Stress ◽  
Cfst Columns

Continuous Cooling Transformation of Undeformed and Deformed High Strength Crack-Arrest Steel Plates for Large Container Ships

2019 ◽  
Vol 38 (2019) ◽  
pp. 183-191 ◽  
Author(s):  
Yongfeng Qi ◽  
Jing Li ◽  
Chengbin Shi ◽  
Qintian Zhu
Keyword(s):  
High Strength ◽  
Crack Arrest ◽  
Steel Plates ◽  
Granular Bainite ◽  
Deformation Condition ◽  
Stored Energy ◽  
Transformation Behavior ◽  
Continuous Cooling ◽  
Upper Bainite ◽  
Large Container

AbstractThe phase transformation behavior of crack-arrest steel during continuous cooling either with or without deformation at high temperatures was investigated. By carefully examining the microstructures of continuous cooled samples, we found that pearlite, quasi-polygonal ferrite (QPF), acicular ferrite (AF), granular bainite (GB), upper bainite, lath-like bainite and martensite/austenite will exist depending on cooling rates and transformation temperatures in both conditions of deformation and without deformation after austenization. The transformation curves of AF and GB moved toward the left in deformation condition in comparison with that of without deformation condition, which indicated that deformation promoted the formation of QPF and AF; meanwhile, deformation inhibited the formation of bainite. Finer bainite and the accompanying M/A could be obtained by reducing the bainite nucleation activation energy as follows: (i) increasing the undercooling by increasing the cooling rate; (ii) increasing the stored energy by deformation of the austenite.

Brittle Crack Propagation/Arrest Behavior in T-Joint Structure of Heavy Gauge Steel Plates

2012 ◽  
Vol 706-709 ◽  
pp. 914-919 ◽  
Author(s):  
Tsunehisa Handa ◽  
Kimihiro Nishimura ◽  
Hiroshi Shiomi ◽  
Seishi Tsuyama
Keyword(s):  
Crack Propagation ◽  
Steel Plate ◽  
Crack Arrest ◽  
Steel Plates ◽  
Brittle Crack ◽  
K Value ◽  
Joint Structure ◽  
Large Heat ◽  
Large Container ◽  
Arrest Toughness

Brittle crack arrestability is extremely important in welded joints of heavy gauge steel plates used in large container ships. Recently, much attention has been focused on potential crack propagation along welds using large heat input. This paper examines the application of a T-joint to the strength deck structure of container ships to enhance crack arrestability. The crack arrest toughness, Kca, for crack arrest was varied. The ESSO test of T-joint components showed that brittle crack was arrested at the T-joint if the steel plate used for the flange had a high Kca value in the range from 4900 to 7300N/mm3/2. FE-analysis of the stress intensity factor K indicated that brittle crack propagation was arrested under the condition that the K-value at the running crack tip was less than the Kca of the material. In the T-joint, it was noted that the K-value around the area of the deepest point of the crack decreased and was finally less than the Kca of the flange plate when the brittle crack penetrated suddenly into the flange plate to a 10mm depth. This phenomenon shows the advantage of using a T-joint for brittle crack arrest in the flange plates of strength deck structures.

Welding of thin steel plates: a new model for thermal analysis

1992 ◽  
Vol 27 (1) ◽  
pp. 203-209 ◽  
Author(s):  
B. V. Kumar ◽  
O. N. Mohanty ◽  
A. Biswas
Keyword(s):  
Thermal Analysis ◽  
Steel Plates ◽  
New Model ◽  
Thin Steel

A physics based model to simulate brittle crack arrest in steel plates incorporating experimental and numerical evidences

2019 ◽  
Vol 221 ◽  
pp. 106660 ◽  
Author(s):  
Fuminori Yanagimoto ◽  
Kazuki Shibanuma ◽  
Katsuyuki Suzuki ◽  
Toshiyuki Matsumoto
Keyword(s):  
Crack Arrest ◽  
Steel Plates ◽  
Brittle Crack

scholarly journals Simplified Evaluation Method for Brittle Crack Arrest Toughness of Steel Plates Exploiting Charpy Impact Test

2018 ◽  
Vol 104 (3) ◽  
pp. 155-165 ◽  
Author(s):  
Hiroyuki Shirahata ◽  
Teppei Okawa ◽  
Takehiro Inoue ◽  
Kohsaku Ushioda
Keyword(s):  
Evaluation Method ◽  
Impact Test ◽  
Charpy Impact ◽  
Crack Arrest ◽  
Charpy Impact Test ◽  
Steel Plates ◽  
Brittle Crack ◽  
Arrest Toughness

A Crack Arrest Test Using a Toughness Gradient Steel Plate

1995 ◽  
Vol 117 (4) ◽  
pp. 330-334 ◽  
Author(s):  
H. Okamura ◽  
G. Yagawa ◽  
T. Hidaka ◽  
Y. Urabe ◽  
M. Satoh ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Steel Plate ◽  
Crack Arrest ◽  
Steel Plates ◽  
Brittle Crack ◽  
Four Point Bending ◽  
Heavy Section ◽  
Bending Load ◽  
Plate Specimen ◽  
Arrest Toughness

A crack arrest test was carried out using a toughness gradient steel plate with three layers to study the concept of crack arrest toughness. Four-point bending load with thermal shock was applied to the large flat plate specimen with a surface crack. Five crack initiations and arrests were observed during the test and the propagated crack bifurcated. Finally, cracks were arrested at the boundary of the first and the second layer, except for a small segment of the crack. The first crack initiation took place slightly higher than the lower bound of KIc data obtained by ITCT specimens. That is, the KIC concept for brittle crack initiation was verified for heavy section steel plates. The first crack arrest took place within the scatter band of KIa and KId data for the first layer. That is, the KIa concept appears applicable for crack arrest of a short crack jump.

The Hitachi Model HS-8 Electron Microscope

1967 ◽  
Vol 25 ◽  
pp. 238-239
Author(s):  
H. Akabori ◽  
K. Nishiwaki ◽  
K. Yoneta
Keyword(s):  
Electron Microscope ◽  
New Model ◽  
Predecessor Model

By improving the predecessor Model HS- 7 electron microscope for the purpose of easier operation, we have recently completed new Model HS-8 electron microscope featuring higher performance and ease of operation.

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