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Failure theories: identify Guest’s (maximum shear stress) theory statement. Statement: Failure occurs when the maximum shear stress in a biaxial stress state reaches the shear stress at the elastic limit in a simple tension test. Choose the correct option (True/False).

Difficulty: Easy

True
False
True only for brittle materials
False; that is distortion energy theory

Correct Answer: True

Explanation:

Concept
Guest's (Tresca) theory, also called the maximum shear stress theory, states that yielding begins when the maximum shear stress in a complex state equals that at yield in simple tension. The statement given is exactly this criterion.

Contrast
Distortion energy (von Mises) is a different criterion based on second deviatoric invariant.

Final Answer
True

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