scholarly journals A criterion for the fragmentation of bubbly magma based on brittle failure theory

Nature ◽  
10.1038/45210 ◽  
1999 ◽  
Vol 402 (6762) ◽  
pp. 648-650 ◽  
Author(s):  
Youxue Zhang
Keyword(s):  
Brittle Failure ◽  
Failure Theory

The Theoretical Measure of the Ductility of Failure for All Isotropic Materials in All States of Stress1

2016 ◽  
Vol 83 (6) ◽  
Author(s):  
Richard M. Christensen
Keyword(s):  
Stress State ◽  
Brittle Failure ◽  
Failure Stress ◽  
Isotropic Materials ◽  
Failure Theory

The ductile/brittle failure theory for homogeneous and isotropic materials is extended to give a rational and mathematically rigorous measure for the ductility of failure. This new failure number methodology is completely developed and proved to be valid and general. It applies to all isotropic materials as subjected to any and all states of stress. Not only does the failure theory predict the safety or failure for any given stress state, it then projects the quantitative ductility level for the failure stress state. Many important examples are given with detailed interpretations of the results and with guides for general usage.

Evaluation of Ductile/Brittle Failure Theory and Derivation of the Ductile/Brittle Transition Temperature

2015 ◽  
Vol 83 (2) ◽  
Author(s):  
Richard M. Christensen
Keyword(s):  
Transition Temperature ◽  
Brittle Failure ◽  
Evaluation Process ◽  
Isotropic Materials ◽  
Brittle Transition ◽  
Failure Theory ◽  
Ductile Brittle Transition Temperature ◽  
Brittle Transition Temperature ◽  
Materials Failure

A recently developed ductile/brittle theory of materials failure is evaluated. The failure theory applies to all homogeneous and isotropic materials. The determination of the ductile/brittle transition is an integral and essential part of the failure theory. The evaluation process emphasizes and examines all aspects of the ductile versus the brittle nature of failure, including the ductile limit and the brittle limit of materials' types. The failure theory is proved to be extraordinarily versatile and comprehensive. It even allows derivation of the associated ductile/brittle transition temperature. This too applies to all homogeneous and isotropic materials and not just some subclass of materials' types. This evaluation program completes the development of the failure theory.

The Failure Theory for Isotropic Materials: Proof and Completion

2019 ◽  
Vol 87 (5) ◽  
Author(s):  
Richard M. Christensen
Keyword(s):  
Brittle Failure ◽  
Ductile Failure ◽  
Isotropic Materials ◽  
Failure Theory ◽  
History Of ◽  
Failure Properties ◽  
Complete Form ◽  
The Many ◽  
Entire Theory

Abstract This work represents the completion of the many developments in recent years on failure theory for homogeneous and isotropic materials. Presented here is the resulting failure formalism in final and technically complete form. Significant further results are also given for the verification of the failure formalism. The scope of this paper goes from the history of misguided failure theory investigations right up to the present final tested forms ready for applications. For every predicted failure level in terms of the stresses, there is an accompanying ductility level. This ranges from brittle failure up to fully ductile failure. The entire theory is calibrated by only two specified parameters (failure properties). Nothing else is needed. The seemingly interminable, actually centuries long search for the missing theory of failure has finally been brought to a resolute and successful conclusion.

Proof of the Splitting Mode of Compressive Brittle Failure and Integration With General Failure Theory

2019 ◽  
Vol 86 (9) ◽  
Author(s):  
Richard M. Christensen
Keyword(s):  
Uniaxial Compression ◽  
Special Interest ◽  
Brittle Failure ◽  
Difficult Problem ◽  
Theoretical Treatment ◽  
Isotropic Materials ◽  
Failure Theory ◽  
Mode Of Failure ◽  
Technical Capability

The problem of special interest is the nature of the mode of failure in uniaxial compression at the brittle limit. This problem is known by observation to undergo a splitting mode of failure. The present work gives a full theoretical treatment and proof for this mode of failure. The general failure theory of Christensen for isotropic materials provides the basis for the derivation. The solution demonstrates the depth of technical capability that is required from the failure theory to treat such a classically difficult problem.

scholarly journals An evaluation of the failure modes transition and the Christensen ductile/brittle failure theory using molecular dynamics

2018 ◽  
Vol 474 (2219) ◽  
pp. 20180361 ◽  
Author(s):  
Richard Christensen ◽  
Zhi Li ◽  
Huajian Gao
Keyword(s):  
Molecular Dynamics ◽  
Brittle Failure ◽  
Failure Modes ◽  
Shear Bands ◽  
Failure Criteria ◽  
Test Material ◽  
Full Density ◽  
Modes Of Failure ◽  
Failure Theory ◽  
Voids Growth

The Christensen ductile/brittle failure theory can be interpreted in terms of the associated failure modes, those of shear bands and voids nucleation. Their conjunction is then termed as the failure modes transition and it is studied here using molecular dynamics. The test material is taken as a particular metallic glass, CuZr. First the theoretical failure criteria are evaluated and then the theoretical failure modes transition is evaluated. Both are found to perform extremely well. The overall failure theory contains three modes of failure, the two already mentioned plus a fracture criterion. A general conclusion from the work is that the voids nucleation criterion is of unusually broad relevance. Voids nucleation leads to voids growth and then further deteriorating mechanisms and ultimately failure. But the voids nucleation is the precipitating event of all that subsequently occurs in this process. Access to these capabilities is gained through the failure theory for all homogeneous, full density, isotropic materials. Only two standard testing measurements are needed to calibrate the entire failure theory, including the transitions.

scholarly journals The ductile/brittle transition provides the critical test for materials failure theory

2018 ◽  
Vol 474 (2210) ◽  
pp. 20170817 ◽  
Author(s):  
Richard M. Christensen
Keyword(s):  
Uniaxial Tension ◽  
Brittle Failure ◽  
Functional Form ◽  
Three Dimensional ◽  
Failure Surface ◽  
Critical Test ◽  
Full Account ◽  
Brittle Transition ◽  
Failure Theory ◽  
Materials Failure

It is reasoned that any materials failure theory that claims generality must give full account of ductile versus brittle failure behaviour. Any such proposed theory especially must admit the capability to generate the ductile/brittle transition. A derivation of the failure surface orientations from a particular isotropic materials failure theory reveals that uniaxial tension has its ductile/brittle transition at T / C  = 1/2, where T and C are the uniaxial strengths. Between this information and the corresponding ductile/brittle transition in uniaxial compression it becomes possible to derive the functional form for the fully three-dimensional ductile/brittle transition. These same general steps of verification must be fulfilled for any other candidate general failure theory.

ALLOY STEEL 3.5Ni-1.8Cr-0.4Mo-0.1V

Alloy Digest ◽  
1984 ◽  
Vol 33 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Alloy Steel ◽  
Brittle Failure ◽  
Water Immersion ◽  
Heat Treating ◽  
Water Spray ◽  
Heavy Duty ◽  
High Hardenability ◽  
Steel Mills

Abstract Alloy Steel 3.5Ni-1.8Cr-0.4Mo-0.1V is highly suitable for massive components, usually more than four inches thick. It has high hardenability which in a water-spray or water-immersion quench contributes to the formation of sizeable amounts of martensite along with some bainite, and possibly a little ferrite. On tempering, the martensite adds to toughness and lowers the temperature of transition from tough to brittle failure. This steel is suitable for intermediate-duty and heavy-duty generator and turbine rotors, large axles and shafts, large gears and ship forgings. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and machining. Filing Code: SA-404. Producer or source: Alloy steel mills and foundries.

Lamellar Tearing Observations Regarding the Application of European Standards in the Field of Welded Steel Constructions

2018 ◽  
Vol 69 (6) ◽  
pp. 1352-1354
Author(s):  
Anamaria Feier ◽  
Oana Roxana Chivu
Keyword(s):  
Bearing Capacity ◽  
Brittle Failure ◽  
Engineering Practice ◽  
Steel Bridge ◽  
Railway Bridge ◽  
Welded Steel ◽  
Direct Replacement ◽  
Lamellar Tearing ◽  
European Standards ◽  
Comprehensive Study

The problem of corrosion for old steel bridges in operation is often solved by direct replacement of elements or structure. Only a few studies have been done to determine the efforts influenced by corrosion in those elements. In general, it is considered that a corroded element has exceeded the bearing capacity and should be replaced, but if the corroded element is secondary it could be treated and kept. A factor in the rehabilitation of an old steel bridge in operation is the aspect of structure. If the structure is corroded, rehabilitation decision is taken is easier. Lamellar tearing describes the cracking that occurs beneath the weld and can be characterized as a brittle failure of steel, in the direction perpendicular to the plane of rolling. The paper presents a comprehensive study on lamellar tearing and summarizes some conclusions about the prevention of them. The conclusions will be exemplified in the case of a railway bridge, with a main truss girder. The paper presents also some observations regarding the stress analysis in fillet welds, resulting from the engineering practice.

Root Cause Analysis of an Unexpected Brittle Failure in a Carbon Steel Slab

2020 ◽  
pp. 105205
Author(s):  
Ali Keramatian ◽  
Abbas Bahrami ◽  
Amir Hossein Darougheh ◽  
Shahin Zare
Keyword(s):  
Carbon Steel ◽  
Brittle Failure ◽  
Root Cause Analysis ◽  
Cause Analysis ◽  
Root Cause ◽  
Steel Slab
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