scholarly journals Modified wood: review of efficacy and service life testing

2015 ◽  
Vol 168 (4) ◽  
pp. 187-203 ◽  
Author(s):  
Graham Ormondroyd ◽  
Morwenna Spear ◽  
Simon Curling
Keyword(s):  
Service Life ◽  
Life Testing ◽  
Modified Wood

scholarly journals Condition of production and operation of railway sleepers from various materials

2018 ◽  
Vol 7 (4) ◽  
pp. 157-166 ◽  
Author(s):  
Татьяна Курьянова ◽  
Tatyana Kuryanova ◽  
Алексей Платонов ◽  
Aleksey Platonov ◽  
Марина Михеевская ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Physical And Mechanical Properties ◽  
Railway Track ◽  
Natural Wood ◽  
Coniferous Wood ◽  
And Performance ◽  
Whole Life Cycle ◽  
Production And Operation ◽  
Modified Wood

Sleepers are elements of the upper structure of the railway track. When choosing a material for the manufacture of sleepers, we are based on such basic factors as cost for the whole life cycle and performance characteristics. In connection with the depletion of wood stocks in the world and the short life of wooden sleepers, the process of using sleepers made of reinforced concrete, metal and plastic goes intensively. The service life of pine sleepers is no more than 12-15 years, reinforced concrete sleepers are about 30-50 years old, plastic ones are up to 40 years old, and metal ones are 50-60 years old. However, wooden sleepers differ in the least cost, they practically do not have restrictions on the laying areas, and in some cases have a clear advantage over other materials. Reinforced concrete, metal and plastic sleepers are more expensive than wooden ones, have a longer payback period and are recommended to be laid on roads with high freight intensity, where they can pay off as quickly as possible. It is possible to reduce the shortcomings of sleepers made of natural wood, using modified hardwood for their manufacture, which, by pressing, will be stronger than the sleepers made of natural wood, which, in its physical and mechanical properties, is not inferior to sleepers made of natural coniferous wood. However, a certain disadvantage of the modified wood is its ability to change size and shape with increasing humidity. Stabilization of sizes and forms of modified wood can be increased by impregnating it with the composition of antiseptic with stabilizer. The predicted service life of sleepers from modified wood can be significantly higher than that of wooden sleepers made of natural coniferous wood.

Virtual Engine Dynamometers in the Service Life Testing of Transmissions

2011 ◽  
Vol 11 (4) ◽  
pp. 48-53
Author(s):  
Norm Newberger ◽  
Dennis J. Paige
Keyword(s):  
Service Life ◽  
Life Testing

Multiple Frequency Ultrasonic Detection of Subsurface Near-Race Inclusions for Improved Fatigue Life Performance

2015 ◽  
Author(s):  
Ping Hu ◽  
Joseph A. Turner ◽  
Constantine Tarawneh ◽  
Brent Wilson ◽  
Allen J. Fuller
Keyword(s):  
Surface Wave ◽  
Service Life ◽  
Contact Fatigue ◽  
Steel Production ◽  
Rolling Contact ◽  
Life Testing ◽  
Damage Initiation ◽  
Steel Cleanliness ◽  
Inclusion Morphology ◽  
The Impact

The importance of steel cleanliness for the performance of tapered roller bearings has been clearly established and has led to on-going improvements in steel production methods. The presence of non-metallic impurities within the steel can result in hard/brittle inclusions that may serve as initiation sites for damage due to sub-surface rolling contact fatigue (RCF) if the inclusions lie within the near-race of the bearing components due to the high mechanical stress present. Current inspection standards define steel cleanliness with respect to bulk inclusion morphology, which limits inspection to a small area that may or may not be representative of the entire steel heat. In this presentation, ultrasonic surface wave methods are described for detecting subsurface inclusions directly on finished bearing inner and outer rings. We expand on our previous work to exploit the different inspection depths that can be achieved with different measurement frequencies. The impact of the different inspection depths is quantified through simulated service life testing with heavy axle loading conditions. For this study, bearing components were first subjected to ultrasonic surface wave testing at three different frequencies to identify near-race inclusions. The simulated service life testing was then used to assess the onset and propagation of RCF failure. RCF spall initiations correlated highly with the positions identified by the ultrasonic inspections suggesting that this approach has a predictive potential. However, additional research is needed to establish the specific criteria needed for such predictions with respect to the inclusion location along the race, the depth from the race surface, the inclusion morphology and the inclusion mechanical properties. This work is anticipated to improve the understanding of RCF damage initiation which will lead a higher level of safety for railroad operations.

scholarly journals Accelerated Life Testing to Predict Service Life and Reliability for an Appliance Door Hinge

2015 ◽  
Vol 1 ◽  
pp. 169-180 ◽  
Author(s):  
Seunghyeon Cheon ◽  
Hyunsoo Jeong ◽  
So Young Hwang ◽  
Seokmoo Hong ◽  
Joseph Domblesky ◽  
...  
Keyword(s):  
Service Life ◽  
Accelerated Life Testing ◽  
Life Testing ◽  
Accelerated Life ◽  
Door Hinge

Accelerated Service Life Testing of Automotive Vehicles on a Test Course

1992 ◽  
Vol 21 (1) ◽  
pp. 89-108 ◽  
Author(s):  
S. Colin ASHMORE ◽  
Allan G. PIERSOL ◽  
Joseph J. WITTE
Keyword(s):  
Service Life ◽  
Life Testing
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