The critical stress value of a column subjected to tensile a
     The critical stress value of a column subjected to tensile axial load can be determined using the Euler equation  for the short columns failure occur essentially as a result of yield stress.  As the stress concentration factor decreases, the fatigue life also decreases.  The slope of the S-N curve is negative.  Endurance stress value is approximately equal to half of the yield tensile strength  Goodman equation is valid only when a time history has tensile mean stress values  for completely reversed loading R=0.1. 
  
  Solution
1.true ....euler equation is valid for columns.
2., false
3 false
4.false i..it decreases and then remains constant
5.false that depens on material
6.true
7 false

