Once the calculation has been made, it is necessary to compare the values of tensions obtained with some value that determines whether the component may or may not support the loads applied to it.
There are many criteria for failure, but the most common ones are the following:
Von Misses criterion: This criterion consists of comparing a value obtained from the stress state called Von Misses stress with the elastic limit. If the Von Misses stress is smaller than the elastic limit, the material is within the elastic zone. This criterion is used for steel, aluminium, etc
Criterion of Coulomb-Morh: This criterion is used for those materials that have different limits for tensile and for compression. In this case when the minimum principal stress is positive, it compares the maximum principal stress with the tensile limit (first quadrant). When the maximum principal stress is negative, it compares the minimum principal stress with the limit to compression (third quadrant). In any other case the expression is applied. This criterion is used for cast iron.