Stato Di Crack Di X-Plane 12 !FREE!
A huge iceberg (1270 km) the size of the county of Bedfordshire has broken off the 150-m thick Brunt Ice Shelf, almost a decade after scientists at British Antarctic Survey (BAS) first detected growth of vast cracks in the ice.
Stato di crack di X-Plane 12
During January, this rift pushed northeast at up to 1 km per day, cutting through the 150-m thick floating ice shelf. The iceberg was formed when the crack widened several hundred metres in a few hours on the morning of 26th Feb, releasing it from the rest of floating ice shelf.
The Brunt Ice Shelf is probably the most closely monitored ice shelf on Earth. A network of 16 GPS instruments measure the deformation of the ice and report this back on a daily basis. European Space Agency satellite imagery (Sentinel 2), TerraSAR-X, NASA Worldview satellite images, US Landsat 8 images, ground penetrating radar, and on-site drone footage have been critical in providing the basis for early warning of changes to the Brunt Ice Shelf. These data have provided science teams with a number of ways to measure the width of Chasm 1 and changes to the Halloween Crack and North Rift crack, with very high precision. In addition, scientists have used computer models and bathymetric maps to predict how close the ice shelf was to calving.
Abstract:The application fields of friction stir welding technology, such as aerospace and transportation, has high safety requirements and fatigue is the dominant failure mode for weldments. It is of great significance to understand the fatigue properties of friction stir welded joints. This paper provides an overview of the fatigue mechanism, influencing factors, crack growth rate, and fatigue life assessment. It is found that the fatigue performance of friction stir welded joints can be affected by welding process parameters, test environment, stress ratio, residual stress, and weld defect. The optimized process parameters can produce high quality weld and increase the weld fatigue life. Laser peening is an effective post weld treatment to decrease fatigue crack growth rate and improve material fatigue life.Keywords: fatigue; friction stir welding; aluminum alloy; SN curve; crack growth rate 041b061a72