Residual stress and Lónsöræfi: Difference between pages

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Lónsöræfi is a wilderness area in south-east Iceland. The region is characterised by its varied geological formations. These mostly date from a period 5-7 million years ago when the volcano Kollumúlaeldstöðvar was active. The glacier tongues of the eastern extreme of Vatnajökull also impose themselves on the area. Visible to the north-west is Snæfell (1833m), the highest peak in Iceland that isn't part of a glacier. The mountains within the area itself include Sauðhamarstindur (1319m) and Jökulgilstindar (1313 m).

Lónsöræfi, while less known and less accessible than areas such as Skaftafell and the Southern Highlands, is nevertheless popular with hikers. A transport service from Stafafell farm into the reserve via all-terrain bus is available. Alternatively, the recent construction of a bridge for walkers over the Jökulsá í Lóni river at Eskifell has improved access for hikers. There are mountain huts at Geldingafell, Múlaskáli and Egilssel run by regional associations of Ferðafélag Íslands. A 4-6 day walking route fromSnæfell to Stafafell is possible via the Eyjabakkajökull glacier tongue. The area can also be reached fromGeithellnadalur. The nearest settlements of any size are Höfn and Djúpivogur.

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+'''Lónsöræfi''' is a wilderness area in south-east [[Iceland]]. The region is characterised by its varied geological formations. These mostly date from a period 5-7 million years ago when the volcano Kollumúlaeldstöðvar was active. The glacier tongues of the eastern extreme of [[Vatnajökull]] also impose themselves on the area. Visible to the north-west is Snæfell (1833m), the highest peak in Iceland that isn't part of a glacier. The mountains within the area itself include Sauðhamarstindur (1319m) and Jökulgilstindar (1313 m).
-'''Residual stresses''' are [[Stress (physics)|stresses]] that remain after the original cause of the stresses (external forces, heat gradient) has been removed. They remain along a cross section of the component, even without the external cause. Residual stresses occur for a variety of reasons, including inelastic deformations and heat treatment.  Heat from [[welding]] may cause localized expansion, which is taken up during welding by either the molten metal or the placement of parts being welded. When the finished weldment cools, some areas cool and contract more than others, leaving residual stresses.  Castings may also have large residual stresses due to uneven cooling.
-==Controlled residual stress==
-While uncontrolled residual stresses are undesirable, some designs rely on them. For example, [[toughened glass]] and [[pre-stressed concrete]] depend on residual stress to prevent [[brittle]] failure. A demonstration of the effect is shown by [[Prince Rupert's Drop]], where a molten glass globule is quenched to produce a toughened outer layer.
-[[Image:fullsizedrops.jpg|&nbsp;|thumb|300px|Prince Rupert's Drops]]
+Lónsöræfi, while less known and less accessible than areas such as [[Skaftafell]] and the Southern Highlands, is nevertheless popular with hikers. A transport service from Stafafell farm into the reserve via all-terrain bus is available. Alternatively, the recent construction of a [[bridge]] for walkers over the [[Jökulsá í Lóni]] river at [[Eskifell]] has improved access for hikers. There are mountain huts at [[Geldingafell]], [[Múlaskáli]] and [[Egilssel]] run by regional associations of [[Ferðafélag Íslands]]. A 4-6 day walking route from[[ Snæfell]] to Stafafell is possible via the [[Eyjabakkajökull]] glacier tongue. The area can also be reached from[[ Geithellnadalur]]. The nearest settlements of any size are [[Höfn]] and [[Djúpivogur]].
-[[Bolted joint]]s use residual stress to avoid subjecting bolts to [[fatigue (material)|fatigue]].  A gradient in [[martensite]] formation leaves residual stress in some swords with particularly [[hardness|hard]] edges (notably the [[katana]]), which can prevent the opening of edge cracks.
+==External links==
-In certain types of gun barrels made with two tubes forced together, the inner tube is compressed while the outer tube stretches, preventing cracks from opening in the rifling when the gun is fired. Parts are often heated or dropped into [[liquid nitrogen]] to aid assembly.
+* [http://www.eldhorn.is/stafafell/index.htm Stafafell Farm and Lónsöræfi travel service]
+* [http://english.ust.is/National-Parks/Protectedareas/Lonsoraefi/ Lónsöræfi page of the Icelandic Environment and Food Agency]
+* [http://www.horn.is/ferdafelag/ Ferðafélags Austur-Skaftafellssýslu (in Icelandic)]
+* [http://www.fljotsdalsherad.is/ferdafelag/ Ferðafélag Fljótsdalshéraðs (in Icelandic)]
+* [http://www.isafold.de/lonsoraefi98/default.htm Account of a trek through Lónsöræfi, with photos (in German)]
+* [http://www.hi.is/~annadora/lonsoraefi.pdf Lengthy report into tourism in Lónsöræfi, with photos (in Icelandic)]
+* [http://www.flickr.com/photos/gislos/187640145/ Photo] [http://pond.org.uk/galleries/Iceland,%202000/index2.html Photos] [http://www.pbase.com/orelime/lonsoerafi Photos] [http://public.fotki.com/Ellaosk/lnsrfi/ Photos] [http://public.fotki.com/gunnasteina/fer__lnsrfi/page3.html Photos]
+* [http://www.islandsmyndir.is/html_skjol/halendid/Lonsoraefi-2007-07-21/index.html Gallery of Lónsöræfi from www.islandsmyndir.is]
+{{Iceland-geo-stub}}
-==Press fits==
-Press fits are the most common intentional use of residual stress. Automotive wheel studs, for example are pressed into holes on the wheel hub.  The holes are smaller than the studs, requiring force to drive the studs into place.  The residual stresses fasten the parts together.  [[nail (engineering)|Nail]]s are another example where the stress created by penetration of wood then helps to keep the nail in place.
-==See also==
-* [[Shot peening]]
-* [[Autofrettage]]
-* [[Tempered glass]]
-* [[Prince Rupert's Drop]]
-* [[Prestressed concrete]]
-==References==
-*Cary, Howard B. and Scott C. Helzer ([[2005]]).  Modern Welding Technology.  Upper Saddle River, [[New Jersey]]: Pearson Education.  ISBN 0-13-113029-3.
-==External links==
-*[http://www.msm.cam.ac.uk/phase-trans/residual.html Residual stress information at Cambridge University]
-*[http://www.twi.co.uk/j32k/protected/band_3/ksrhl001.html Residual stresses at The Welding Institute]
-*[http://www.protoxrd.com/residualstressinfo.htm Residual Stress Information at PROTO Manufacturing]
+{{coord missing|Iceland}}
-[[Category:Metalworking]]
-[[Category:Continuum mechanics]]
+{{DEFAULTSORT:Lonsoraefi}}
-[[de:Eigenspannung]]
+[[Category:South Iceland]]
-[[sk:Zvyškové napätie]]