Experimental Stress Analysis of a Nylon Engine Cooling Fan

An unsatisfactory stress condition existing in a molded nylon engine cooling fan was identified in strain gauge testing in a vehicle application. In order to reduce the high stress condition observed at the blade-hub interface, an experimental stress analysis program was initiated. Various blade contours were evaluated on an axial shaker and in a test facility simulating the strain levels observed in the vehicle. The results were utilized to modify the mold and sample molded fans confirmed the analysis method.