The curing deformation mechanism and deformation control methods of honeycomb panels

Controlling warpage during hot-press curing of aluminum honeycomb panels is crucial for dimensional accuracy and structural performance. This deformation is mainly caused by uneven temperature distribution and the resulting thermal mismatch between the upper and lower face-sheets. To address this issue, this study investigates the influence of non-woven fabric thickness on the thermal deformation behavior of the panels. A thermos-mechanical finite element model was established based on sandwich panel theory, and an equivalent mechanical model of the honeycomb core was developed. Combined with autoclave experiments, the evolution of the temperature field and deformation field under different non-woven fabric thicknesses was systematically analyzed. The results indicate that the non-woven fabric layer delays the heating of the upper face-sheet through its thermal resistance, thereby improving temperature uniformity between the upper and lower face-sheets. As the fabric thickness increased from 0 to 7 mm, the flatness of the panel continuously improved, with maximum deformation reduced by 24.1%. However, a clear diminishing marginal effect was observed: the improvement in deformation suppression became notably smaller in the 5–7 mm thickness range. Experimental data agreed well with simulations, and the maximum deformation prediction error remained within 5%, validating the proposed “non-woven fabric thickness – temperature field – deformation field” mechanism. This study provides a theoretical basis for selecting the non-woven fabric thickness in the manufacturing process, suggesting that a thickness around 5 mm offers the best balance between material cost and quality control.