Question

From Rankine's hypothesis Rankine, criteria for failure of brittle material is:

• A. Maximum principal stress
• B. Maximum strain energy
• C. Maximum shear stress
• D. Maximum shear strain energy

Answer 1

Answer:

A. Maximum principal stress

Rankine's criteria for failure of brittle material is based on maximum principal stress. The permanent set takes place when maximum principal stress equals yield point stress. For design, maximum principal stress should not exceed working stress. The equation is $\sigma_{1,2} \le \sigma_y$ for no failure and $\sigma_{1,2}\le \sigma/FOS$ for design. For no shear failure,$\tau \le 0.57\sigma_y$