Answer:
a). Soderberg method
Step-by-step explanation:
A straight line joining the endurance limit,
on the ordinate and to the yield strength,
on the abscissa is know as Soderberg line.
The Soderberg line is the most conservative failure criteria and in this there is no need to consider yielding point in this case.
The equation for Soderberg is given by
![(\sigma _(m))/(S_(yt))+(\sigma _(a))/(S_(e))=1](https://img.qammunity.org/2020/formulas/engineering/college/35xx1mew1cszhaq5flsa5fw7edee558a05.png)
where
is mean stress
is amplitude stress