Elastic Strength of Propellers - An Analysis by Matrix Methods (Including a Programmer's Manual and a User's Manual).

Abstract : The determination of displacements and stresses in a propeller blade under the influence of a hydrodynamic pressure load is investigated. Also a simplified approach to the free, undamped vibration of the blade is suggested. The finite element method of analysis is used to analyze the blade as a shell or as a combination of a three dimensional solid and a shell. For the vibration problem, the complete blade was idealized by shell element only. Constant stress tetrahedra and rectangular prism elements were used for the analysis of the three dimensional solids. A combination of both kinds of elements was found to cause no algorithmic difficulties or inaccuracies in the results and to provide the flexibility to approximate irregular boundaries by the tetrahedron. The stiffness of the shell element was obtained by the superposition of the stiffness of the plane stress element and the fully compatible plate bending element. (Author)