# GATE Questions & Answers of Failure Theories

## What is the Weightage of Failure Theories in GATE Exam?

Total 5 Questions have been asked from Failure Theories topic of Machine Design subject in previous GATE papers. Average marks 1.40.

The principal stresses at a point inside a solid object are $\sigma_1=100\;\mathrm{MPa}$ $\sigma_2=100\;\mathrm{MPa}$ and $\sigma_3=0\;\mathrm{MPa}$. The yield strength of the material is 200 MPa. The factor of safety calculated using Tresca (maximum shear stress) theory is $n_T$ and the factor of safety calculated using von Mises (maximum distortional energy) theory is $n_V$. Which one of the following relations is TRUE?

Which one of the following is the most conservative fatigue failure criterion?

A machine element is subjected to the following bi-axial state of stress: ; ; .If the shear strength of the material is 100 MPa, the factor of safety as per Tresca’s maximum shear stress theory is