Beam and Link

- May 1, 2020 at 1:37 pm
  
  ansysquestions2995
  Subscriber
  
  Why does changing the code from Beam to Link lead to an error when I try to solve>
  
  *get , crosssection ,SECP ,matid ,PROP , AREA ! Read area property from geometry into variable crosssection
  
  ET ,matid , LINK180 ! Assign element type LINK180
  
  SECTYPE , matid , LINK ! Associates section type link
  
  SECDATA , crosssection ! Provide area data to link
  
  Also..Why does sizing solve this problem?
  
  Also what is the basic difference between beam and link element and how to decide which one is
  
  suitable for our particular case?
- May 1, 2020 at 5:59 pm
  
  peteroznewman
  Subscriber
  
  You want exactly one element on a line body if it is a LINK. If there are more elements, then the nodes in the center have no lateral stiffness and cause the error. When solving {F} = [K]{X} for unknown {X}, there is no solution if [K] = 0.
  
  Beam elements have lateral stiffness so [K] is not 0.
  
  Links only carry tension and compression and are straight lines.
  
  Beams can bend and can carry moments as well as tension and compression forces.
- May 11, 2020 at 7:36 am
  
  ansysquestions2995
  Subscriber
  
  Thank you for your answer...
  
  If there is no lateral stiffness in link element according to the solver ,shouldn't it just simplify the matrix by
  
  applying zero in the lateral movement nodes instead of giving an error?
  
  And only those intermediate points will have zero lateral stiffness correspondingly which will just be a part of global stiffness matrix.
  
  Also why did sizing solve this issue?