Fatigue metal

Fig. 14.1. Before it broke, this steel bolt held o seat onto its mounting at Milan airport. Whenever someone sat down, the lower part of the cross-section went into tension, causing a crack to grow there by metal fatigue (Chapter 15 crack No. 1). When someone got up again, the upper part went into tension, causing fatigue crack No. 2 to grow. Eventually the bolt failed by fast fracture from the larger of the two fatigue cracks. The victim was able to escape with the fractured bolt ...

In calculating the system and barrier failures, consideration should be given to radiation embrittlement, chemical reactions, thermal shock, and metal fatigue. 

Lognormal distribution Similar to a normal distribution. However, the logarithms of the values of the random variables are normally distributed. Typical applications are metal fatigue, electrical insulation life, time-to-repair data, continuous process (i.e., chemical processes) failure and repair data. 

Temperature is an important parameter for safety. At extreme temperatures, tlie risk of metal fatigue, stress corrosion cracking, and vessel rupture increases dramatically. 

In the early days of the industrial revolution, steam engine explosions were a real problem. Metal fatigue... 

If the nuts do not loosen, metal fatigue may occur at the source of soft-foot. Cracks can develop in the support base/frame and, in extreme cases, the soft-foot may actually break off. 

High heat-transfer rates and sufficient cooling via internal, two-phase flow and circulation are consequently necessary to ensure that modem boilers operate below their particular critical heat-flux (CHF) conditions. This minimizes poor thermal efficiency performance, risks of thermal metal fatigue, and probable tube failures from excessive temperatures. 

In addition to the many different forms of boiler section ferrous corrosion already described, several other less common types occasionally develop. In particular, corrosion processes may evolve that are interrelated with stress, deposition, and/or high temperatures (thermal effect corrosion), and together these may lead to metal fatigue (metal fatigue corrosion), metal failure, and even more serious problems such as the risk of a boiler explosion. 

Step 3. Methane gas evolves during decarburization corrosion and builds up pressure, causing hydrogen embrittlement metal fatigue and eventual tube ... 

Line failure due to vibration induced metal fatigue released hot oil under high pressure which ignited and spread to other portions the plant. 

The most obvious source a gas accumulation is a fuel leak. Other rare losses have occurred due to lubrication failures, causing the equipment to over heat, with subsequent metal fatigue and disintegration. Once disintegration occurs heat release from the combustion chamber will occur along with shrapnel and small projectiles which will be thrown free from the unit from inertia momentum of the rotating device. 

Uses. In the manufacture of semiconductors, injection lasers, and solar cells in the manufacture of glass, graphite, and cathode oscillographs in metal alloys to prevent corrosion and metal fatigue... 

The main advantage of this group of materials is resistance to pressure. However, there are also disadvantages, such as a high rigidity in comparison to bone, local pitting corrosion due to the fact that there is no protective layer, metal fatigue and friction corrosion. The latter results in rejection which is caused by released ions. 

Most elastic elements will have a service life of close to a million cycles, if the cycle time is not less than 5 seconds. If longer service life or higher-cycle frequencies are required, metal fatigue tends to limit the usefulness of elastic elements, and special designs, such as sealed piston elements, should be considered. 

To apply the probabilistic methods to estimate micro-cracks possible nucleation within a joint metal (fatigue damage processes). 

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