strenght

• initial and actual configurations are almost identical

  
  

  (no influence of displacements onto static values)

  • from newtons first law
  • a body in motion tends to have constant speed and direction unless acted upon by an external force
• Complex (combined) structure - a structure with parts of different

  types: beam, frame, truss, arch, etc
• three shields connection is stable/ rigid if each pair is connected by two bars (or 1 hinge = 2 bars )

  • the points of intersection of each pair ARE NOT collinear (współliniowe)
• Virtual veocity - consistent with the constraints
• Invariants of a tensor

  • are independent of transformation due to rotation of the frame
• Stress state

  collection of all stress vectors from all cross sections
• hookes law

  • deformation of an object is directly proportional to the deforming force
  • F=k * x
• q1 acts horizontally

  q2 acts VERTICALLY
• dilatation is the relative change of volume due to deformation

  and

  equals the sum of the diagonal elements of the strain tensor.  Thus,
• The difference between the effects of two different but statically equivalent loads (applied on sufficiently small

  part of the boundary) becomes very small at sufficiently large distances from load
• any deformation of a rigid body consists of:

  • translation and rotation of the principal axes
  • and elongations or shortening along these axes