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Fatigue cracks can grow from material or manufacturing defects from as small as 10 μm. When the rate of growth becomes large enough, fatigue striations can be seen on the fracture surface. Striations mark the position of the crack tip and the width of each striation represents the growth from one loading cycle.
Static fatigue tests can be used to determine the lifespan of a material with different loads and environmental conditions. [ 13 ] [ 14 ] However, accurately assessing a material's true static fatigue life presents challenges, as these tests often require an extended duration and there is significant variability in the results.
The U.S. Environmental Protection Agency (EPA) prohibits disposing of certain materials down drains. [4] Therefore, when hazardous chemical waste is generated in a laboratory setting, it is usually stored on-site in appropriate waste containers, such as triple-rinsed chemical storage containers [5] or carboys, where it is later collected and disposed of in order to meet safety, health, and ...
Vibration fatigue is a mechanical engineering term describing material fatigue, caused by forced vibration of random nature. An excited structure responds according to its natural-dynamics modes, which results in a dynamic stress load in the material points. [ 1 ]
Low cycle fatigue (LCF) has two fundamental characteristics: plastic deformation in each cycle; and low cycle phenomenon, in which the materials have finite endurance for this type of load. The term cycle refers to repeated applications of stress that lead to eventual fatigue and failure; low-cycle pertains to a long period between applications.
Curve A shows the fatigue behavior of a material tested in air. A fatigue threshold (or limit) is seen in curve A, corresponding to the horizontal part of the curve. Curves B and C represent the fatigue behavior of the same material in two corrosive environments. In curve B, the fatigue failure at high stress levels is retarded, and the fatigue ...
Hazardous wastes must often be stabilized and solidified in order to enter a landfill and must undergo different treatments in order to stabilize and dispose of them. Most flammable materials can be recycled into industrial fuel. Some materials with hazardous constituents can be recycled, such as lead acid batteries.
Widespread fatigue caused the in-flight failure of the fuselage on Aloha Airlines Flight 243. Widespread fatigue damage (WFD) in a structure is characterised by the simultaneous presence of fatigue cracks at multiple points that are of sufficient size and density that while individually they may be acceptable, link-up of the cracks could suddenly occur and the structure could fail. [1]