Maximum Normal Stress Theory W. Rankine ~1850 Hide Text 37 Failure will occur when the magnitude of the major principal stress reaches that which caused fracture in a simple tension test. Here we plot Mohr's circle for this stress state. Maximum Normal Stress Theory W. Rankine ~1850 Hide Text 38 Failure will occur when the magnitude of the Get Theory of Failure Multiple Choice Questions (MCQ Quiz) with answers and detailed solutions. Download these Free Theory of Failure MCQ Quiz Pdf and prepare for your upcoming exams Like Banking, SSC, Railway, UPSC, State PSC. Get Started. Exams. SSC Exams. Maximum principal stress theory (Rankine's theory) develop, the Rankine Theory is not correct and will give less conservative results. Rankine's theory is not intended to be used for determining earth pressures directly against a wall (friction angle does not appear in equations above). The theory is intended to be used for determining earth pressures on a vertical plane within a mass of soil. 4-8 Principal or Normal stress theory. (Rankines Theory): It is assumed that the failure or yield occurs at a. point in a member when the max. principal or. normal stress in the biaxial stress system. reaches the limiting strength of the material in a. simple tension test. In this case max. principal stress is calculated in. By using these stresses different hypothesis of failure were made. According to these, following are the commonly used five theories of failure. Maximum Principle Stress Theory (Rankin's Theory) Maximum Principle Strain Theory (Saint Venant's Theory) Maximum Shear Stress Theory (coulomb, Tresca and Guest's Theory)