Damage mechanics

O Brien, T.K., Characterization of Delamination Onset and Growth in a Composite Laminate in Damage in Composite Materials, ASTM STP 775, p. 140-167,1982 Poursartip, A. Ashby, M. F., Beaumont P.W.R., The Fatigue Damage Mechanics of Fibrous Laminates in Proceedings of the European Workshop on Nondestructive Evaluation of Polymers and Polymer Matrix Composites, Polymer NDE (edited by Khg. Ashbee), Technomic Publishing, p. 250-260, 1984... 

An experienced inspection engineer will attempt to identify the characteristics of a given structure to determine potential. specific critical damage mechanisms. No individual major concrete structure can be adequately analysed by simple mass-accumulation of data and using criteria, which are based on standard codes. This does not mean that either data-collection or available criteria are not useful, but they should be exercised with care and flexibility and the procedures for inspection customised for the given structure. 

R. Viswanathan, in Damage Mechanisms andEp e Assessment of High Temperature Components, ASM, Materials Park, Ohio, 1989. 

Fig. 17. Variety of subcritical damage mechanisms in fiber-reinforced composites, that lead to a highly diffuse damage 2one. (a) Fiber cracking, (b) matrix...

All areas of the cooling water system where a specific form of damage is likely to be found are described. The corrosion or failure causes and mechanisms are also described. Especially important factors influencing the corrosion process are listed. Detailed descriptions of each failure mode are given, along with many common, and some not-so-common, case histories. Descriptions of closely related and similarly appearing damage mechanisms allow discrimination between failure modes and avoidance of common mistakes and misconceptions. 

Attached anodes provide the particular advantage of proportionately low grounding resistance for the protection current because the actual anode body is set into both sloping sides of the plastic body as long narrow strips. The disadvantage is that the body is exposed on the ship s side and can easily be damaged mechanically. 

Turbine rotating blades cannot be field-repaired if they are cracked. If one or two blades are damaged mechanically, the manufacturer may recommend field repair or replacement of the damaged blades. However, if several blades are fatigue cracked, it is recommended that the entire set be replaced, since the remaining blades have been exposed to the same operating conditions and, therefore, have little fatigue life left. 

Explosion is burning that takes place sonically, hence, a shock front is produced. The damage mechanisms are physical destruction from the shock wave, collateral damage from falling structures, and human bums. Suffocation and poisoning are not usually associated with an explosion because of its short duration. A chemical explosives such as nitroglycerine, trinitrotoluene, dynamite, and others were discussed in Section 7.2.6. 

Film is removed and mechanical damage to underlying metal is the dominant damage mechanism. 

L.M. Kachanov, Introduction to Continuum Damage Mechanics, Martinus Nijhoff, 1986. 

Electrochemical and nonelectrochemical ways to protect metals against corrosion can be distinguished. The nonelectrochemical ways include dense protective films that isolate the metal against effects of the medium and may be paint, polymer, bitumen, enamel, and the like. It is a general shortcoming of these coatings that when they are damaged mechanically, they lose their protective action, and local corrosion activity arises. 

Markwick PRL, Doltsinis NL, Schlitter J (2007) Probing irradiation induced DNA damage mechanisms using excited state Car-Parrinello molecular dynamics. J Chem Phys 126 045104... 

This method of presenting the topic of blast damage mechanisms was chosen primarily because it highlights the relationships between blast wave properties and structural response or damage. But, we hope that you now also know that the P-i or isodamage curves for structures can be useful design tools. 

Design practices stem from standard fire test procedures in which the temperature history of the test furnace is regarded as an index of the destructive potential of a fire. Thus, the practice of describing the expected effects and damage mechanism is based on temperature histories. This standard design practice is convenient but lacks accuracy in terms of structural performance. The severity of a fire should address the expected intensity of the heat flux that will impact the structure and the duration of heat penetration. A simple analysis of the expect nature of an unwanted fire can be based on the heats of combustion and pyrolysis of the principal contents in the facility. The heat of combustion will identify the destructive nature of the fire, while the heat of pyrolysis will identify the severity of the fire within the compartment itself and will also identify the destructive potential of the fire in adjacent spaces. 

Fiber-reinforced composites, subcritical damage mechanisms in, 16 188 Fiber-reinforced metal-matrix composites, 16 171... 

Spin trapping is an often-used technique in the study of possible radical production in biological systems (for reviews see Kalyanaraman, 1982 Mason, 1984 Mottley and Mason, 1989), particularly by the detection and monitoring of spin adducts of the hydroxyl and hydroperoxyl ( OOH) radicals in view of their relation to possible damage mechanisms. This is a large area of research which it is not possible to cover in a limited review, and the treatment will therefore be restricted to a discussion of the electron transfer properties of biochemical systems (for a review on the application of the Marcus theory to reactions between xenobiotics and redox proteins, see Eberson, 1985) and... 

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