Experimental stress analysis is outside the scope of the forum. However shear strain energy (Von Mises), although generally considered to be the more accurate method of assigning stresses in a three dimensional distribution, is not used in practical problems. Our software uses the less onerous Tresca method. (ASME Section VIII, Division 2). The simple maximum shear stress is considered accurate enough for just about all practical applications. For ASME Section VIII, Division 1, we only consider direct stress. The method has been used for many years with success.