Steepest angle at which granular materials can be piled before slumping
For the Wallace Stegner novel, see Angle of Repose. For the angle of friction between two solid objects, see Friction § Angle of friction.
The angle of repose, or critical angle of repose,[1] of a granular material is the steepest angle of descent or dip relative to the horizontal plane on which the material can be piled without slumping. At this angle, the material on the slope face is on the verge of sliding. The angle of repose can range from 0° to 90°. The morphology of the material affects the angle of repose; smooth, rounded sand grains cannot be piled as steeply as can rough, interlocking sands. The angle of repose can also be affected by additions of solvents. If a small amount of water is able to bridge the gaps between particles, electrostatic attraction of the water to mineral surfaces increases the angle of repose, and related quantities such as the soil strength.
When bulk granular materials are poured onto a horizontal surface, a conical pile forms. The internal angle between the surface of the pile and the horizontal surface is known as the angle of repose and is related to the density, surface area and shapes of the particles, and the coefficient of friction of the material. Material with a low angle of repose forms flatter piles than material with a high angle of repose.
The term has a related usage in mechanics, where it refers to the maximum angle at which an object can rest on an inclined plane without sliding down. This angle is equal to the arctangent of the coefficient of static friction μs between the surfaces.
^
Mehta, A.; Barker, G. C. (1994). "The dynamics of sand". Reports on Progress in Physics. 57 (4): 383. Bibcode:1994RPPh...57..383M. doi:10.1088/0034-4885/57/4/002. S2CID 250898376.
The angleofrepose, or critical angleofrepose, of a granular material is the steepest angleof descent or dip relative to the horizontal plane on which...
AngleofRepose is a 1971 novel by Wallace Stegner about a wheelchair-using historian, Lyman Ward, who has lost connection with his son and living family...
the size and shape of grains can impact angleofrepose significantly. As the roundness of materials increases, the angleofrepose decreases since there...
occurs Critical angleof attack, in aerodynamics; the angleof attack which produces the maximum lift coefficient Critical angleofrepose, in engineering;...
exerted over a greater distance. The angleof friction, also sometimes called the angleofrepose, is the maximum angle at which a load can rest motionless...
West). Stegner explained his use of unpublished archival letters briefly at the beginning ofAngleofRepose but his use of uncredited passages taken directly...
novel AngleofRepose (Pulitzer Prize, 1972) is based directly upon Mary Hallock Foote's extensive personal correspondence. Stegner used the outline of her...
maximum inclination corresponds to the angleofreposeof the mean debris particle size. The exact definition of scree in the primary literature is somewhat...
gradient of the resulting volcano is dependent both on the angleofrepose as well as the speed at which the volcano is weathered. The angleofrepose is,...
until the slope angle reaches the critical angleofrepose (that is, the steepest angle the sand can maintain, where it is on the verge of collapse from...
outer slope angle is ultimately determined by the age of the subducting slab. The inner slope angle is determined by the angleofreposeof the overriding...
stress and therefore it cannot reside at a tilted angle without flowing (that is, it has zero angleofrepose.) A powder on the other hand is a solid, not...
material's inherent angleofrepose. The speed of rotation and the positioning of the articulable gate provides a consistent feed of your material. Drum...
properties of MCC are measured to qualify its suitability to such utilization, namely particle size, density, compressibility index, angleofrepose, powder...
mysteries of friendship, and it extends Stegner's distinguished body of work that had already earned him a Pulitzer Prize (for 1971's AngleofRepose) and...
(particle mobility), angleofrepose, abrasiveness and corrosivity, among others. Bulk material handling systems are typically composed of stationary machinery...
Demon Copperhead is a 2022 novel by Barbara Kingsolver. It was a co-recipient of the 2023 Pulitzer Prize for Fiction, and won the 2023 Women's Prize for Fiction...
additional reworking or effort. This is known as the angleofrepose, and a prime example is the surface of sand dunes. Similarly, sediments may drape over...
as the slip face, facing away from the wind, downwind, at the angle of reposeof the sand in question, approximately 30–35 degrees for medium-fine dry...
Bernard Forest de Bélidor and Leonhard Euler (1750), who derived the angleofreposeof a weight on an inclined plane and first distinguished between static...
of piles of sand and found empirically two critical angles: the maximal stable angle θ m {\displaystyle \theta _{m}} and the minimum angleofrepose θ...
tunnel in Roughing It. Wallace Stegner also references the tunnel in AngleofRepose. "Nevada Historical Markers". Nevada State Historic Preservation Office...
sine curve of the volcano is due to the balance between erosion and eruption, defined by the angleofreposeof ash. The steepest upper slopes of the volcano...
density of a basin. In this sense, "unstable" is not used in the sense of the gradient of the hillslope being greater than the angleofrepose and therefore...