A Photoelastic Investigation of Stresses in the Hub of a Proposed 20,000-Shp Controllable-Pitch Propeller

摘要

A three-dimensional photoelastic model of the hub of a proposed 20,000-shaft horsepower controllable-pitch marine propeller was built and tested. Stresses were determined by strain gages and photoelastic measurements at selected locations for the 'crash-stop' load condition. The hub stresses for the case of one blade hitting a submerged object were investigated to a limited extent by strain gages. Stress concentrations at the inside corners were extremely high, causing stresses of the order of 65,000 psi to 84,000 psi in the prototype. It is recommended that larger fillet radii be used at all inside corners to reduce the stresses. (Author)