What is absolute stress??

Replies

• 

  skipper

  I would say it means the stress limit, for safety limit of the construction.
  
  Do the requirements mean that a 20mm section can't bend more than 2mm vertically? If so you can apply a fixed solution then find a material that fits in the volume and satisfies the 200MPa requirement.
• 

  aztechmayhem

  So is it simply just sigma=F/A ?
  
  
  i just included the question on my 1st post. Have a look
• 

  skipper

  Truss
  
  might be a starting point...
• 

  aztechmayhem

  I know what a truss is, i just don't know what is absolute stress. I've been searching books and the internet, still cant find it. Thanks anyway.
• 

  skipper

  Well, there is no such thing for starters; I would say it's a term used to mean the point of failure for a structure - the absolute stress limit.
  If instead you leave out the word "absolute", then it says: "the stress limit".
• 

  aztechmayhem

  Ok, I would go with that. So now im going forward with stress = F/A, I'm going to see my lecturer afterwards. Hope i get it right 😀
• 

  Rohan_sK

  The Absolute stress mentioned is the Maximum Permissible Stress of the material, including the Factor Of Safety for the design.
  
  It means that for the given load the dimensions you choose for the structure must be such that the total force perunit area of the tubes must not exceed 200 MPa limit.
  
  And this must be done keeping the value of diameter D and thickness t such that the structure bears the load as well as the value of D and t do not be less than 20mm and 1mm respectiely.
  
  So first calculate the stresses in each memebers for the given oads and the maximum deflection given. Then go in for the dimensions of the tubes so as to satisfy both, the Maximum Permissible Stress and the Minimum Dimensions of D and t that will allow the Stress in permissible ranges keeping the volume of the tubes the lowest, simultaneously.
• 

  jhbalaji

  It's a maximum permissible stress that a material can withstand.