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buxZED
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What condition defines a principal stress?
thx
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Loki1342 said:Since I'm studying Engineering I should probably be able to explain this to you in my own words, but this site does a good job of it:
http://www.efunda.com/formulae/solid_mechanics/mat_mechanics/plane_stress_principal.cfm
If you consider a given stress state, principal stresses are defined as stresses that are normal stresses only. So take the easy case of a thin plate, and apply a tensile stress to one end (i.e. try to stretch it). In that case, the principal stresses would be normal to the sides of the plate. If you had a beam with a rectangular cross section in pure bending, the principal stresses would just be equal to the bending stresses, and are tensile and compressive stresses on the top and bottom surface of the beam, assuming you've got a point force (for example) P acting normal to the bottom surface (in the positive direction, bending the beam into an upside down U). Things like I beams are a little different, and in that case you use Mohr's Circle to calculat principal stresses and shear stresses; the website covers that in a good amount of detail.
If I've missed anything or explained anything ambiguously, someone let me know and I'll try to do a better job of it. :P
Principal stress is a type of stress that occurs in a material at a specific point and is oriented along the direction of a principal axis. It is a measure of the maximum stress that a material experiences at that point.
Principal stress is different from other types of stress, such as normal stress and shear stress, because it takes into account the direction of the stress relative to the material's principal axes. This allows for a more accurate analysis of the stress state at a given point.
Principal stress is significant in materials science because it helps engineers and scientists understand how materials respond to external forces. It can also be used to determine the failure points of a material, allowing for the design of more robust and durable structures.
Principal stress can be calculated using mathematical equations that take into account the normal stress components, shear stress components, and the orientation of the principal axes. These equations are typically solved using computer software or specialized calculators.
Yes, principal stress can be measured experimentally using techniques such as strain gauges, which can measure the deformation of a material in response to applied forces. These measurements can then be used to calculate the principal stress at a specific point.