The Split, Layered, Cup-and-Cone Tensile Fracture

1968 ◽  
Vol 90 (1) ◽  
pp. 8-12 ◽  
Author(s):  
R. J. Hrubec ◽  
L. A. Jackman ◽  
W. R. Clough
Keyword(s):  
Flat Plate ◽  
Tensile Testing ◽  
Stress Conditions ◽  
Tensile Fracture ◽  
Plate Steel ◽  
Electron Fractography ◽  
Longitudinal Cracks

Quenched and tempered plate steel is capable of modified cup-and-cone fractures involving one or more longitudinal cracks “parallel” to the flat plate surfaces. The occurrence was verified by tensile testing of three steels at a variety of temperatures. Electron fractography revealed that quasi-cleavage, shear lips, tearing, and normal rupture were active, being identified by modified river patterns and by elongated and equiaxed dimples resulting from the coalescence of microvoids. The brittle longitudinal cracks are formed shortly before final rupture. Application of the Bridgman plasticity solution for necked tensile specimens shows that the split, layered, fracture occurs under unique stress conditions.

Neck-and-Split Tensile Fracture of Anisotropic Plate Steel

1969 ◽  
Vol 91 (1) ◽  
pp. 39-43 ◽  
Author(s):  
W. R. Clough ◽  
J. L. Solomon
Keyword(s):  
Rolling Direction ◽  
Void Formation ◽  
Testing Temperature ◽  
Tensile Fracture ◽  
Plate Steel ◽  
Electron Fractography ◽  
Alloy Plate ◽  
Temperature Ranges ◽  
Longitudinal Split ◽  
Distinct Temperature

Rolling-direction tensile specimens of 0.31 C quenched and tempered alloy plate steel displayed cup-and-cone, split-layered, neck-and-split, and square-break fracture configurations over distinct temperature ranges as testing temperature was lowered from 300 to −320 F. Formation of the neck-and-split configuration was investigated in terms of stress state, temperature, void formation, and anisotropy. Electron fractography identified quasicleavage as the fracture mode of the initially occurring longitudinal split. The brittle fracture phenomenon resulting in the neck-and-split fracture of plate specimens occurs under a unique combination of conditions.

The Rosette, Star, Tensile Fracture

1968 ◽  
Vol 90 (1) ◽  
pp. 21-27 ◽  
Author(s):  
W. R. Clough ◽  
R. M. Vennett ◽  
R. J. Hrubec
Keyword(s):  
Electron Microscope ◽  
Tensile Testing ◽  
Tensile Fracture ◽  
Fracture Modes ◽  
Fracture Topography ◽  
Fracture Configuration ◽  
Temperature Ranges ◽  
Fracture Theory ◽  
Quenched And Tempered Steel ◽  
Tempered Steel

A type of tensile fracture topography encountered fairly often in certain temperature ranges with specimens from forgings, billets, rod, and bar of quenched and tempered steel, is the “star” or “rosette.” Having available several steels which had been shown to be capable of exhibiting the rosette, star, fracture, tensile testing was done to establish the temperature ranges for which this fracture configuration was applicable. Explanations of the fracture, and determinations of the fracture modes, were sought through experimentation involving metallography and the electron microscope, and by application of continuum mathematical plasticity-fracture theory.

Study on Forming Mechanism of Lamination Defect of AH36 Shipbuilding Plate Steel

2012 ◽  
Vol 562-564 ◽  
pp. 106-110 ◽  
Author(s):  
Rui Feng ◽  
Rui Tang Zhang ◽  
Sheng Li Li ◽  
Guan Hong Kong ◽  
Xin De Zhu
Keyword(s):  
Steel Plate ◽  
Solidification Process ◽  
Tensile Fracture ◽  
Surface Zone ◽  
Plate Steel ◽  
Forming Mechanism ◽  
Deformation Stage ◽  
Continuous Casting Slab ◽  
Transmission Electron ◽  
Deformation And Fracture

The lamination defect makes the mechanical properties deterioration along the thickness of steel plate and therefore finding out the forming mechanism is of great significance for production of shipbuilding plate steel. The tensile fracture and microstructure characteristics on AH36 shipbuilding plate steel of lamination defect were studied with Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), etc. The results show that the strength-toughness properties vary widely at different thickness of the steel plate due to different ferrite grain size, and the center zone firstly yields and steps into plastic deformation stage due to coarse ferrite grain subjected to tensile stress, while the surface zone is still in elastic deformation stage due to relatively fine ferrite grain. The inconsistency of deformation and fracture leads to fracture separation, namely lamination. The continuous banded Widmanstätten structure, strip-shaped sulphide inclusions and mixed ferrite grain distributed at the center of shipbuilding plate steel create conditions for the lamination defect, which are important reasons for fracture separation. Widmanstätten structure at the center of steel plate has relationship with coarse austenite grain, and strip-shaped sulphide inclusions have relationship with centerline segregation of continuous casting slab during solidification process.

A 30 ton biaxial tensile testing machine

1969 ◽  
Vol 4 (1) ◽  
pp. 22-26 ◽  
Author(s):  
H Fessler ◽  
J K Musson
Keyword(s):  
Flat Plate ◽  
Tensile Testing ◽  
Testing Machine ◽  
Tensile Testing Machine ◽  
Test Pieces ◽  
Biaxial Tensile ◽  
Form Pressure ◽  
Biaxial Tensile Testing

The machine is intended for a flat-plate testpiece, one face of which has to be unobstucted throughout the test. Plates up to 36 in long, 27 in wide, and 3/4 in thick can be accommodated. Hydraulic rams actuated by air-hydraulic pumps exert completely independent tensions on cruciform test pieces through spherical bushes. Satisfactory direct-load readings were obtained form pressure gauges.

CASS Fracture Tests Using Flat Plate Specimens With a Surface Flaw

2015 ◽  
Author(s):  
Kiminobu Hojo ◽  
Wataru Nishi ◽  
Shotaro Hayashi
Keyword(s):  
Stainless Steel ◽  
Flat Plate ◽  
Thermal Aging ◽  
Limit Load ◽  
Surface Flaw ◽  
Tensile Fracture ◽  
Ferrite Number ◽  
Fracture Tests ◽  
Depth Curve ◽  
Two Parameter

JSME rules for fitness for service have flaw acceptance rules for cast austenitic stainless steel (CASS) pipes. They allow applying two-parameter and elastic-plastic fracture mechanics methods using Z-factor. However they do not clearly describe whether limit load method is applicable for the case of no or low thermal aging condition. The authors performed tensile fracture tests using flat plate specimens with a surface flaw and confirmed that limit load method is applicable in the conditions of no thermal aging and even fully saturated thermal aging with high ferrite number. Also the plate with a shallow flaw ruptured at the critical stress defined by nominal stress at rupture-flaw depth curve in the code case which was determined by the similar flat plate tests of stainless steel or nickel alloy specimens. These results will be reflected to the revision of the code.

Microstructure and Mechanical Properties of Heavy Gauge Plate by Vacuum Cladding Rolling

2010 ◽  
Vol 97-101 ◽  
pp. 324-327 ◽  
Author(s):  
Guang Ming Xie ◽  
Zong An Luo ◽  
Hong Guang Wang ◽  
Guo Dong Wang ◽  
Li Jun Wang
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Tensile Testing ◽  
Steel Plate ◽  
Electron Beam Welding ◽  
Tensile Fracture ◽  
Vacuum Level ◽  
Interface Defects ◽  
Microstructure And Mechanical Properties ◽  
Rolling Method

The cladding steel plate was successfully produced using vacuum cladding rolling method. In cladding steel plate, cladding interface vanished and was replaced new recrystallized grains, and no interface defects or inclusions were detected. Z direction tensile testing indicated that tensile fracture occurred in basal materials, i.e. strength and contraction of cross area are those of basal materials. Furthermore, with decreasing vacuum level of electron beam welding, size and amount of interface inclusions would obviously increase.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

Self-Injurious Behavior vs. Nonsuicidal Self-Injury

Crisis ◽  
2012 ◽  
Vol 33 (2) ◽  
pp. 106-112 ◽  
Author(s):  
Christopher M. Bloom ◽  
Shareen Holly ◽  
Adam M. P. Miller
Keyword(s):  
Positive Reinforcement ◽  
Empirical Investigation ◽  
High Stress ◽  
Animal Research ◽  
Stress Conditions ◽  
Human Populations ◽  
Pharmacological Interventions ◽  
Self Injury ◽  
Cns Stimulant ◽  
Nonsuicidal Self Injury

Background: Historically, the field of self-injury has distinguished between the behaviors exhibited among individuals with a developmental disability (self-injurious behaviors; SIB) and those present within a normative population (nonsuicidal self-injury; NSSI),which typically result as a response to perceived stress. More recently, however, conclusions about NSSI have been drawn from lines of animal research aimed at examining the neurobiological mechanisms of SIB. Despite some functional similarity between SIB and NSSI, no empirical investigation has provided precedent for the application of SIB-targeted animal research as justification for pharmacological interventions in populations demonstrating NSSI. Aims: The present study examined this question directly, by simulating an animal model of SIB in rodents injected with pemoline and systematically manipulating stress conditions in order to monitor rates of self-injury. Methods: Sham controls and experimental animals injected with pemoline (200 mg/kg) were assigned to either a low stress (discriminated positive reinforcement) or high stress (discriminated avoidance) group and compared on the dependent measures of self-inflicted injury prevalence and severity. Results: The manipulation of stress conditions did not impact the rate of self-injury demonstrated by the rats. The results do not support a model of stress-induced SIB in rodents. Conclusions: Current findings provide evidence for caution in the development of pharmacotherapies of NSSI in human populations based on CNS stimulant models. Theoretical implications are discussed with respect to antecedent factors such as preinjury arousal level and environmental stress.

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