Tool-part interaction in composites microwave curing: Experimental investigation and analysis

The tool-part interaction of composite materials during microwave curing is different from conventional thermal heating, mainly because of the rapid and selective heating mechanism of microwave. Novel measurement and analysis approaches of microwave curing induced tool-part shear stresses were established and verified in this article. The optical fiber sensors were placed in the groove of tool surface to measure the strain values, which were converted to the tool-part shear stresses. A comprehensive friction coefficient was calculated by the shear stresses, and it was presented by considering the thermal expansion mismatch of composite/tool and the chemical shrinkage of resin. In order to validate the accuracy of model, the shape dimension of microwave cured scaling down leading edge of the composite part was measured to compare with simulation model. The results exhibited that the presented model can significantly decrease the prediction error of composite deformation compared with other methods during microwave curing.