我先来贴一个国外工程师的理解：! R8 S$ b6 D9 D' x# ]1 R
Isaac Gaetz, Structural Engineer4 D/ p# ^' D' {! b# r9 C! x
Isaac has 210+ answers and 13 endorsements in Civil Engineering. V/ F! s# N( Q) y
In the field of structural engineering these are closely related terms, and sometimes used interchangeably, though if you want to get specific there are cases where one term is more appropriate than another.5 b& P% \3 J. V. J7 O6 `0 }
- v& n6 @1 x+ W0 m6 T# I) LThese are how I understand the terms, though I'll be curious to see if anyone disagrees.2 w/ M [( R: ]- a5 Z+ q1 J3 Q
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Displacement is the distance from which one node or element (beam, column, frame, etc) moved from its original location. The movement could be from a beam deflecting, but it could also be the result of the entire object moving, un-distorted, like a box sliding on a surface with friction. Displacement can both be measured in terms of distance and in terms of rotation.! L; M) f& b) V1 _- r- G
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Deflection is the distance that an object bends, twists from its original position. I would generally assume that an objects deflection does not include rigid movement of the object.: a' j8 K8 h0 i0 X
8 Z5 v7 l/ W6 M: Q, @5 Q, U, _8 Q* n( VDeformation is the actual distortion that occurs to a structural member. We most commonly discuss elastic and plastic deformations. Elastic deformations are those deformations that, when the loading is removed, will return to the original undeflected shape. Plastic deformations are those that will remain even after the loading is removed.
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Because most structures are securely attached to their foundation, there is general no rigid body motion, and displacement and deflection are particular similar concepts. I would say the outlier is deformations. Displacements and Deflections are generally measures of distance (or ratios of that distance compared to a meaningful value, such as the member length) while deformation is what happened to the member to cause the displacements/deflections.# }2 C ]+ ~+ C5 k
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发表于 2015-7-23 10:51:50
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