Vibration fatigue

Moderate Superheater tube Superheater tube parted from vibration fatigue, causing carryover of boiler water from steam drum and into furnace through superheater leak... 

Another recommended test is to expose samples of propellant to testing on a vibration unit for weeks to months. The specific device we use is a model 100 HLA-D (horizontal) vibration fatigue tester made by All American Tool and Manufacturing Co. Samples, 1 liter in size, are tested, and temperatures can be adjusted easily from below 0° to above 100°F. 

Corrosion fatigue - waterside Corrosion fatigue - fireside Thermomechanical fatigue Vibration fatigue... 

Flexibility The inherent resilience of rubber polymers often provides protection in expansion/contraction modes due to product temperature cycling and flex stress from repetitive work cycles. Plus this flexibility improves the assembly s resistance to vibration, fatigue, impact, shear, elongation, and peel forces. 

Graphite structural components can be subject to thermal, neutron irradiation, and mechanical strains along with vibrational fatigue, chemical attack, and erosion. The potential modes of failure include loss of structural material, cracking, and ultimately, fracture of the component. 

Mechanical vibration fatigue, occurring in small pipes and in socket welds (Fig. 14-6.)... 

Aeroelastic and vibration control technology allows flight vehicles to operate beyond the traditional flutter boundaries, improves ride qualities, and minimizes vibration fatigue damage. Conventional active flutter and vibration control technology relies on the use of aerodynamic control surfaces operated by servo-hydraulic actuators. In this conventional configuration, the... 

Thermoset materials have been used in an essentially similar fusible core method, notably in BMC for the Ford Escort 1.8 diesel. Ford found, however, that reinforced nylon provided better resistance to vibration, fatigue and impact than BMC, and in 1992 adopted 35% glass reinforced PA 66 for its Zeta engine. The 1.8 and 2.0 litre versions use a Bayer grade, while the 1.6 litre engine uses a similar material from Du Pont. (This last, shown in Fig. 6.13, was the first intake manifold incorporating exhaust gas recirculation.)... 

Turbochargers are a new area of application for plastics the hoses in particular have to meet very arduous conditions. Together with hot spots and restricted space, there are the additional problems of low temperature impact, vibration fatigue and resistance to oil mist. For the 1991 Rover M-16 engine, the turbocharger hose was made in an ethylene-acrylic elastomer, extruded around fabric reinforcement in an oval profile (see Fig. 6.18). 

Stability, fluid compatibility and fatigue resistance also are associated with wear resistance. Vibration and pulsation in mechanical systems, or pipelines are common in chemical process industries and can lead to leakages of corrosive fluid. The vibration fatigue is an unavoidable factor which is further aggravated by improper installation of the moving system. Leakages due to these pulsations can be prevented by the installation of flexible rubber expansion joints. 

Some jet pump components are subject to flow induced vibration. Fatigue is a potentially significant degradation mechanism for the jet pump and further evaluation of programmes to effectively manage age-related degradation is required. 

Due to their good damping properties, soybean oil polymers may also find applications in places where the reduction of noise and prevention of vibration fatigue failure is required (39). Several conventional polymers, such as polyacrylates, polyurethanes, polyvinyl acetate, as well as natural, silicone and SBR rubbers, which are currently used as damping materials, might be replaced by soybean oil polymers. Unlike the above-mentioned thermoplastics, soybean oil polymers are capable of efficient damping over wider temperature and frequency ranges (23). 

The munber of small pipe connections on a vessel should be limited. Threaded gauge connections, sample points, and level control nozzles are all subject to mechanical damage, vibration fatigue, and corrosion. The potential failure points are minimized by ... 

Monofilament fabrics are woven from extmded synthetic filaments produced in diameters from 30 jm to 2-3mm.These fabrics have become important as filter media in a broad range of industries and applications. Because of their corrosion resistance, ability to withstand vibration fatigue, uniformity and economy to use, they have replaced a number of other types of media. The chemical and food processing industries, industrial hydraulics, medical, automotive and appliance maikets are major users of monofilament fabrics. These fabrics are available in a range of polymer filaments including nylon, polyester, polypropylene and fluorocarbon materials, in aperture ratings from 5-5000 pm. 

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