Study on the Load Conversion of Bolt-Nut Fasteners between Tightening and Service Conditions

Author(s):  
C. Lv ◽  
A. Liu ◽  
D. Liu ◽  
F. Zhang ◽  
W. Yang
Keyword(s):  
Alloy Digest ◽  
2003 ◽  
Vol 52 (1) ◽  

Abstract Wieland-B18 is a phosphor bronze with a composition that allows usage in slightly more severe service conditions than alloy B16 (UNS C52100). A common application is in slide bearings and slideways. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: CU-696. Producer or source: Wieland Metals Inc., Wieland-Werke AG.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 476
Author(s):  
Mohamed Guerguer ◽  
Sanae Naamane ◽  
Zineb Edfouf ◽  
Olivier Raccurt ◽  
Hassan Bouaouine

This paper reports a study of the influence of outdoor natural aging on paint coatings applied to the back of three commercial solar glass mirrors (A1, C2, and D2) under two different exposure environments (marine and desert) in Morocco for a period of about three years. The aging assessment was carried out through colorimetric measurements and FTIR-ATR (Attenuated total reflection-Fourier transform infrared) analyses of the top coat paints. The obtained results demonstrate that the tested coating system had a high resistance at the desert site. Under the desert environment, no obvious changes to the coating occurred after 350 days. However, at the marine site, some color changes were detected, and the coating got yellow and more matte, especially for mirror A1. FTIR-ATR analyses have indicated many modifications in the intensity of many bonds of infrared spectra especially for paint of this mirror type (A1). This chemical degradation is not only due to UV degradation but also related to many factors, such as humidity, salinity, and rainfall. This finding was concluded after the faster degradation observed on samples exposed at the marine site. The present study confirms the need to use different exposure environments for testing the limits of new protective systems for solar glass mirrors rather than using only the real service conditions. Finally, accelerated tests are necessary for understanding the effect of each degrading parameter and their results should be compared to outdoor tests data for a complete analysis of coatings durability.


2016 ◽  
Vol 92 ◽  
pp. 499-511 ◽  
Author(s):  
Haoliang Huang ◽  
Guang Ye ◽  
Chunxiang Qian ◽  
Erik Schlangen

2021 ◽  
Vol 8 (1) ◽  
pp. 119-129
Author(s):  
Fiammetta Venuti

Abstract Free-edge gridshells represent the majority of built gridshells. Indeed, the gridshell reference geometry usually needs to be trimmed in order to provide building access or to insert the gridshell within an existing building, giving rise to one or more elastic boundaries. Despite the current design practice, so far a very limited number of scientific studies has been devoted to investigate the influence of elastic boundaries on the overall structural behaviour of gridshells. This paper focuses on the effects of the orientation of the boundary structure with respect to the grid direction. This is done by studying the buckling behaviour of an ideal single-layer steel gridshell, for different grid layout (quadrangular, hybrid, triangular) and orientation. The results of the parametric study demonstrate that the sensitivity of free-edge single-layer gridshells to the free-edge orientation strongly depends on the grid pattern. In particular, isotropic gridshells have shown an almost negligible influence of the free-edge orientation in terms of buckling load, in opposition to orthotropic gridshells. Moreover, the change in free-edge orientation induces significant variations of the global structural stiffness for all the layouts, resulting in possibly unacceptable displacements in service conditions.


Author(s):  
A Elia

The objective in introducing tilting systems for passenger trains is to optimize the service, shortening travel time and improving comfort, while making minimum alterations to existing track layouts and service conditions. The development of the Pendolino system is described in this paper, starting from early tests on bogies and on tilting systems. The author then describes the extensive service experience of Fiat, with more than 50 million train-km produced and 100 trainsets in service or under construction for service in European countries. An outline is presented of current developments and the product strategy, together with a description of available R&D prediction/measuring tools.


2007 ◽  
Vol 27 (2) ◽  
pp. 209-233 ◽  
Author(s):  
Enrique López Droguett ◽  
Ali Mosleh

In accelerated lifetime testing (ALT) the assumption of stress-independent spread in life is commonly used and accepted because the resulting models are typically easier to use and data or past experience suggest that such a constrain is sometimes valid. However in many situations and with a variety of products the spread in life does depend on stress, i.e., the failure mechanism is not the same for all stress levels. In this paper the assessment of product time to failure at service conditions from ALT with stress-dependent spread is addressed by formulating a Bayesian framework where the time to failure follows a Weibull distribution, scale parameter dependency on stress is given by the Power Law, and two cases for the dependency between shape parameter and stress are discussed: linear relationship and, in order to allow a comparative analysis, stress-independent shape parameter. A previously published dataset is used to illustrate the procedure.


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