Formation of an incipient crack in the impact fracture of a brittle body by a wedge

1999 ◽  
Vol 35 (1) ◽  
pp. 51-58 ◽  
Author(s):  
G. V. Basheyev ◽  
V. P. Yefimov ◽  
P. A. Martynyuk
Keyword(s):  
Impact Fracture ◽  
Brittle Body ◽  
The Impact ◽  
Incipient Crack

Impact Fracture of Jointed Steel Plates of Bolted Joint of Cars

2014 ◽  
Vol 566 ◽  
pp. 232-237
Author(s):  
H. Ambarita ◽  
M. Daimaruya ◽  
H. Fujiki
Keyword(s):  
Tensile Strength ◽  
Shear Test ◽  
Fracture Criterion ◽  
Shear Fracture ◽  
Impact Fracture ◽  
Bolted Joints ◽  
Steel Plates ◽  
Bolted Joint ◽  
Car Body ◽  
The Impact

The present study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of a lap bolted joint used in the suspension parts of a car body. For the accurate prediction of crash characteristics of car bodies by computer-aided engineering (CAE), it is also necessary to examine the behaviour and fracture of the jointed steel plates subjected to impact loads. Although the actual impact fracture of jointed steel plates of a lap bolted joint in cars is complicated, for simplifying it is classified into the shear fracture and the extractive fracture of jointed steel plates. Three kinds of steel plates, i.e., common steel with the tensile strength of 270 MPa and two high tensile strength steels with the tensile strength of 440 and 590 MPa level used for vehicles, are examined. In the impact shear test, the specimens are made of two plates and jointed by a bolt, and in the impact extractive test the specimens are made of a plate and drilled in the centre for a bolt. The impact shear test of jointed steel plates of lap bolted joints is performed using a modified split Hopkinson bar apparatus, while the impact extractive one is performed using one-bar method. Numerical simulations by a FEM code LS-DYNA are also carried out in order to understand the mechanism of shearing and extractive fractures process of jointed steel plates. The obtained results suggest that a stress-based fracture criterion may be developed for the impact shearing and extractive fractures of jointed steel plates of lap bolted joints used in a car body.

The Effect of Morphology and Distribution of Sulfides on Mechanical Properties and Fatigue Life of Non-Quenched and Tempered Steel

2008 ◽  
Vol 51 ◽  
pp. 11-20
Author(s):  
Ming Tu Ma ◽  
Guo Zhong Li ◽  
Zhi Gang Li ◽  
Hong Zhou Lu
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Fatigue Fracture ◽  
Rolling Direction ◽  
Impact Fracture ◽  
Fatigue Properties ◽  
Bending Fatigue ◽  
Quenched And Tempered Steel ◽  
The Impact ◽  
Tempered Steel

The effect of morphology and distribution of sulfides on tensile, impact and bending fatigue properties of non-quenched and tempered steel 49MnVS3 has been investigated in this paper. Microscopic structure and morphology of sulfides are observed, and impact fracture and fatigue fracture have been analyzed by SEM. The results show that the morphology of sulfides is mostly strip and distributes in ferrite, which affects mechanical properties and fatigue life. The length direction of sulfide strip is parallel to the rolling direction of steel. When the length of sulfide is short relatively and is approximate to the shape of particles. The impact properties and bending fatigue performance of 49MnVS3 are higher. Under those conditions, there are more ductile characteristics in their impact fracture and the fatigue fracture. The reasons for the effect of sulfide morphology on the mechanical and fatigue properties are explained.

Mechanical Properties of La-based Bulk Amorphous Alloys and Composites

2002 ◽  
Vol 754 ◽  
Author(s):  
M.L. Lee ◽  
Y. Li ◽  
W.C. Carter
Keyword(s):  
Mechanical Properties ◽  
Fracture Energy ◽  
Amorphous Alloys ◽  
High Volume ◽  
Intermetallic Phases ◽  
Impact Fracture ◽  
Crystalline Phases ◽  
Bulk Amorphous Alloys ◽  
Glassy Metals ◽  
The Impact

ABSTRACTThe influence of different microstructures of La-based fully amorphous samples and its composites on the impact fracture energy were investigated and discussed. Results showed improvement in fracture energy of glassy metals with intermetallic phases, but deteriorated in the presence of dendrite phases and high volume % of crystalline phases.

Influence of notch severity on the impact fracture behavior of aluminum alloy 7055

1999 ◽  
Vol 20 (6) ◽  
pp. 331-341 ◽  
Author(s):  
Julie Champlin ◽  
J. Zakrajsek ◽  
T.S. Srivatsan ◽  
P.C. Lam ◽  
M. Manoharan
Keyword(s):  
Aluminum Alloy ◽  
Fracture Behavior ◽  
Impact Fracture ◽  
Impact Fracture Behavior ◽  
The Impact

Impact fracture behaviors of three-dimensional braided composite U-notch beam subjected to three-point bending

2018 ◽  
Vol 28 (3) ◽  
pp. 404-426 ◽  
Author(s):  
Baohui Shi ◽  
Shengkai Liu ◽  
Amna Siddique ◽  
Yongcan Du ◽  
Baozhong Sun ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Mouth Opening ◽  
Impact Fracture ◽  
Image Correlation ◽  
Crack Mouth Opening Displacement ◽  
Crack Mouth ◽  
Opening Displacement ◽  
Braided Composite ◽  
Fracture Behaviors ◽  
The Impact

Impact fracture behaviors of three-dimensional braided composites are critical to designing the braided composite parts. Here we report the impact fracture behaviors of three-dimensional braided composite U-notch beam tested on a modified split Hopkinson pressure bar. Crack mouth opening displacement, deformation process, and crack evolutions were recorded with high-speed photography camera. The digital image correlation method was used to calculate deformation contours of the braided composite. A microstructure model of the three-dimensional braided composite U-notch beam was established for analyzing damage evolution and fracture mechanisms. The histories of deformation, the load, and the crack mouth opening displacement were obtained from the impact fracture test and finite element analysis. It was found that the impact fracture resistance and morphologies were influenced by the braided structure and braided yarn orientations. The crack generated at the notch tip and then propagated along the braided angle direction rather than the perpendicular direction that often occurred for isotropic materials, such as the epoxy resin solid. The combinations of different braided angle and yarns are recommended for high impact fracture behavior design.

scholarly journals Non-hardening embrittlement mechanism of pressure vessel steel Ni-Cr-Mo-V welds during thermal aging

2020 ◽  
Vol 12 (2) ◽  
pp. 168781402090456
Author(s):  
Guojun Wei ◽  
Chenglong Wang ◽  
Xingwang Yang ◽  
Zhenfeng Tong ◽  
Wenwang Wu
Keyword(s):  
Weld Metal ◽  
Thermal Aging ◽  
Pressure Vessel ◽  
Impact Test ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Reactor Pressure Vessel ◽  
Impact Fracture ◽  
The Impact ◽  
Reactor Pressure

The mechanical performance of reactor pressure vessel materials is an important factor in the safety and economics of the operation of a nuclear power plant. The ductile-to-brittle transition temperature tested by Charpy impact test is the key parameter for evaluating the reactor pressure vessel embrittlement. In this article, the study of thermal aging embrittlement of temperature sets of reactor pressure vessel surveillance Ni-Cr-Mo-V steel weld metal was conducted by Charpy impact test. The thermal aging effect on the impact fracture behavior was analyzed. The impact test of the three batches of weld surveillance sample indicated that the weld metal embrittled during thermal aging. The study of impact fracture and Auger electron spectroscopy indicated that the element P segregated to the grain boundaries and lowered their cohesion strength during the long-term thermal aging. Therefore, the non-hardening embrittlement of Ni-Cr-Mo-V steel welds in a reactor pressure vessel caused by segregation of impurity elements P occurs during thermal aging.

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