Sustained load crack growth leading to failure in aluminium gas cylinders in traffic

✍ Scribed by J.W.H. Price; R.N. Ibrahim; D. Ischenko

• Book ID: 104383558
• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 803 KB
• Volume: 4
• Category: Article
• ISSN: 1350-6307
• DOI: 10.1016/s1350-6307(97)00018-6

✦ Synopsis

Some common portable aluminium gas cylinders have shown a liability to develop cracking. This cracking has in some cases led to leaks and on occasions to violent and sometimes fatal failures. There are a number of features of this cracking which have not been properly explained. Previous modelling of the growth of these cracks under sustained load has been developed from specimen testing. As is shown in this paper these data produce results which appear to produce values of crack growth which are too slow by a factor of the order of 108 to explain the observed phenomenon. It also appears that crack growth can be rapid even in cylinders with low levels of lead. This paper presents a numerical simulation of the growth of these defects based on the local stresses in the vicinity of the crack edge. This information is related to cracks actually found in cylinders which have leaked or failed in service. From this procedure an equation for the crack growth rate is developed. This also leads to an explanation as to why "leak before break" is not always observed in these cylinders.