fracture mechanics concepts

2008 ◽  
pp. 150-150
Keyword(s):  
Fracture Mechanics ◽  
Mechanics Concepts

Fracture Mechanics in Pavement Engineering: The Specimen-Size Effect

1997 ◽  
Vol 1568 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Anastasios M. Ioannides
Keyword(s):  
Fracture Mechanics ◽  
Size Effect ◽  
Specimen Size ◽  
Pavement Design ◽  
Crack Model ◽  
Design Procedures ◽  
Engineering Discipline ◽  
Pavement Engineering ◽  
Slow Progress ◽  
Mechanics Concepts

Application of fracture mechanics concepts developed in various branches of engineering to the pavement problem can address current limitations, thereby advancing considerably existing pavement design procedures. The state of the art in fracture mechanics applications to pavement engineering is summarized, and an in-depth discussion of one of the major concerns in such applications, the specimen-size effect, is provided. It is concluded that the fictitious crack model proposed by Hillerborg appears most promising for computerized application to pavements. The similitude concepts developed by Bache will be very useful in such efforts. Both the desirability and the scarcity of suitable candidates to replace Miner’s cumulative linear fatigue hypothesis in conventional pavement design are confirmed. Fracture mechanics is shown to be a very promising engineering discipline from which innovations could be transplanted to pavement activities. Nonetheless, it is pointed out that rather slow progress characterizes fracture mechanics developments in general. Pavement engineers clearly need to remain abreast of and involved in fracture mechanics activities.

scholarly journals Critical Stresses in Materials with Cracks

2019 ◽  
Vol 70 (7) ◽  
pp. 2442-2446
Author(s):  
Simona Eugenia Manea ◽  
Vali Ifigenia Nicolof ◽  
Teodor Sima
Keyword(s):  
Fracture Mechanics ◽  
Critical Stress ◽  
Crack Width ◽  
Crack Depth ◽  
Equivalent Stress ◽  
Critical Energy ◽  
Material Behavior ◽  
Experimental Results ◽  
Critical Stresses ◽  
Mechanics Concepts

The fracture mechanics concepts, as well as the concepts introduced on the basis of principle of critical energy, correlated with strength of materials with cracks is analysed. The equivalent stress method of strength was applied to cracked materials, by using the concept of local critical stress. This one depends on the material behavior and the deterioration due to crack. Experimental results have been obtained with specimens of OL304 steel with different cracks. The influence of crack depth and crack width is put into evidence.

scholarly journals A DAMAGE PROGNOSIS METHODOLOGY FOR A SIMPLE CRACKED BEAM

2018 ◽  
Vol 48 (1) ◽  
pp. 43-49
Author(s):  
E. A. PRESEZNIAK ◽  
J. E. PEREZ IPIÑA ◽  
C. A. BAVASTRI
Keyword(s):  
Fracture Mechanics ◽  
Nonlinear Optimization ◽  
Optimization Techniques ◽  
Crack Identification ◽  
Remaining Life ◽  
Damage Prognosis ◽  
Mechanics Concepts ◽  
Dynamic Structures ◽  
High Level

Damage prognosis uses numerical and experimental responses to identify damage in structures or part of them, thus allowing the remaining structural life estimation at a high level of precision. Current methods focalize on crack identification; however, a complete methodology to estimate the remaining life of a cracked structure is less developed. A methodology is presented in this paper drawing on concepts such as wavelets transform, dynamic structures, and vibration signals for crack identification; and fracture mechanics and nonlinear optimization to obtain the remaining life. Finite element theory was applied to obtain its vibration modes. The crack was modeled as a flexural spring connected to the elements in the crack position and the crack identification was performed in the wavelet domain. Nonlinear optimization techniques and fracture mechanics concepts were used to estimate the remaining fatigue life. A numerical-experimental case study is solved to show the fundamentals of this methodology.

Application of fracture mechanics concepts to the failure of wide plates

1985 ◽  
Vol 87 ◽  
pp. 83-88 ◽  
Author(s):  
W. Dahl ◽  
D. Dormagen ◽  
H. Ehrhardt ◽  
W. Hesse ◽  
R. Twickler
Keyword(s):  
Fracture Mechanics ◽  
Mechanics Concepts

Fracture Mechanics Aspects of the Structural Integrity Technology of Spherical Aluminum Containment Vessels for LNG Tankers

1980 ◽  
Vol 102 (3) ◽  
pp. 303-314 ◽  
Author(s):  
J. G. Kaufman ◽  
R. J. Bucci ◽  
R. A. Kelsey
Keyword(s):  
Fracture Mechanics ◽  
Experimental Approach ◽  
Structural Integrity ◽  
Fatigue Loading ◽  
Aluminum Alloy 5083 ◽  
Spherical Tank ◽  
Tank Design ◽  
Stressed Region ◽  
Catastrophic Fracture ◽  
Mechanics Concepts

The Kvaerner-Moss spherical tank design offers significant economic advantage for the shipboard transport of liquefied natural gas. An analytical and experimental approach based on fracture mechanics concepts was used to assist the designer in providing answers to the following basic questions: (1) Might a discontinuity smaller than detectable by nondestructive inspection lead to catastrophic fracture; (2) How fast would such a discontinuity grow under fatigue loading likely to occur during the lifetime of the tank; (3) Could a fatigue crack growing part way through the tank wall precipitate catastrophic fracture before it grows through the wall and is detected as a leak; and (4) If leakage develops, how much time is available to get the ship safely to port for discharge and repair? Both “critical” locations in the tank, i.e., the highest stressed region of the membrane and the equatorial ring, are examined. Available data indicating the safety of spherical tanks fabricated of aluminum alloy 5083-0 is documented.

Rosenhain Centenary Conference - 3. Materials development present and future 3.7. Recent developments in ultra high strength steels and their applications

1976 ◽  
Vol 282 (1307) ◽  
pp. 377-387 ◽  
Keyword(s):  
Fracture Mechanics ◽  
High Strength Steels ◽  
High Strength ◽  
Unstable Fracture ◽  
Materials Development ◽  
Stable Crack Propagation ◽  
Recent Developments ◽  
Ultra High Strength Steels ◽  
Mechanics Concepts ◽  
And Control

As far as the development of new classes of ultra high strength steels is concerned the past decade has seen little progress apart from a few notable exceptions such as the trip steels. However, the introduction of fracture mechanics concepts to the evaluation of material properties has been responsible for an enormous breakthrough in the understanding of the factors which influence the fracture processes in conventional high strength steels. This approach has concerned not only the resistance of these materials to unstable fracture under rising load but also the stable crack propagation which can occur in aggressive environments under static load and in both aggressive and inert environments under cyclic loading conditions. Utilization of fracture mechanics has demonstrated the improvement which can be obtained in the properties of high strength steels through the use of thermomechanical treatments, hardening by intermetallic compounds and control of inclusions. Though much still remains to be learned in each of these fields, this paper highlights some aspects of the progress which has been made in the understanding of the fracture, fatigue and stress corrosion cracking of high strength steels.

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