The mandrel is able to shape the part cavity, therefore is of great significance for composite parts in the manufacturing of carbon fiber reinforced polymer(CFRP) composite part. However, in the manufacturing of composite parts with complex cavities, traditional rigid mandrel cannot be removed out of the cavity in any direction after the outer prepreg is cured. To solve the problem of difficult demolding, a kind of deformable mandrel emerged. The deformable mandrel is rigid at room temperature to support composite part curing. While at relatively high temperatures, the mandrel is softened so that the mandrel can be easily removed from the composite part despite the complex part cavity shape, therefore resolving complications regarding the demolding process. In this paper, a thermoplastic resin material matrix suitable for the preparation of deformable mandrel is proposed. Ingredient and manufacturing flow of the thermoplastic resin matrix are introduced, and the applicability of the proposed matrix with regard to the deformable mandrel is validated through dynamic mechanical analysis.

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Background: When performing the spatial large-scale measurements, the measurement accuracy of laser tracker would decreased with the increase of the measurement distances due to the refraction difference of most optical digital measurement devices. Therefore, this paper proposed a method based on photogrammetry system to improve the large-scale measurement accuracy of the laser tracker. Purpose: The purpose of this method is to improve the large-scale measurement accuracy of the laser tracker by considering the advantages of photogrammetry system such as high measurement accuracy and good portability. Methods: The measurement data from the photogrammetry system would be used as a reference to do correction on measurement results from laser tracker. The coordinate correction method based on Rodrigues’ rotation formula has been discussed. The measurement accuracy of the long-distance point of laser tracker can be significantly improved through the coordinate correction method. Conclusion: Based on the advantages of using photogrammetry system, the proposed method can achieve higher accuracy when measuring the common points at a closer distance than the laser tracker can do when measuring objects far away from instrument. The feasibility of the proposed method has been demonstrated by experiment.