Numerical modeling of curing deformation and process parameters analysis for CFRP/UHMWPE hybrid composite thin-walled special-shaped pipe

In this work, the curing deformation behavior of CFRP/UHMWPE hybrid composite thin-walled special-shaped pipe is studied. The multi-physics coupled mathematical model is established, which includes the thermo-chemical model, the cure kinetics model, the residual stress model and the meso-mechanical model. The finite element simulation is conducted, and the effects of curing process parameters on the curing deformation are systematically examined.Furthermore, the influence weights of curing process parameters on the curing deformation of the pipe are quantitatively explored through Variance decomposition and Shapley value analysis. Results show that the residual stress is mainly concentrated in the regions with large curvatures, and the corners within the same plane of the pipe are more prone to deformation. The contribution priority of each curing process parameter to the curing deformation is: Curing temperature (40.5%) > Heating rate (20.8) > Cooling rate (17.3%) > Curing time (11.4%) > First dwell holding time (6%) > First dwell temperature (4%). Among these, curing temperature ( Tc ) has the most significant influence. As the Tc increases from 157 °C to 207 °C, the maximum deformation increases by 10.9%. This is attributed to the rise in the peak curing rate with increasing Tc , which leads to higher thermal stress. Furthermore, due to the mismatch in the coefficients of thermal expansion (CTE) between the material and the mold, a greater stress gradient develops, resulting in increased deformation after demolding.