Numerical Simulation Of Curing Deformation Of Thermosetting Resin Matrix Composites

Thermosetting resin matrix composites have been widely used in the aerospacefield because of advantages such as light weight, high strength and ease of holisticmolding. Resin matrix composite is an ideal aeronautical structural material, and theamount of advanced composite materials used in aircrafts has become an importantsymbol to measure the level of aviation development.The curing stage is one of the key decisions of the performance of compositeproducts. The curing process of thermosetting resin matrix composites is aninteractive process accompanied by complex chemical reactions and energy exchange.Due to factors such as the thermal expansion of composite materials, the chemicalshrinkage of resin and the interaction with the mold, the composite parts tend to bedeformed when cured. Curing deformation has a very detrimental effect on theperformance of composite products, so the control of curing deformation has been oneof the key technologies of composite structure design. Predicting the curingdeformation through numerical analysis can greatly reduce the raw material and timeconsumption, so as to reduce production costs and shorten the development cycle.This paper focuses on the effects of thermal expansion and chemical shrinkageon the residual stress and curing deformation. A thermal-chemical coupling model isestablished, the temperature and degree of cure field at any time in the curing processis obtained, the influence of dwell temperature, heating rate and thermal conductivityis discussed. It is found that when dwell temperature is lower, heating rate is smallerand thermal conductivity is larger, the distribution of temperature and degree of cureis more uniform. On this basis, a thermal-chemical-elastic model is established. Thespringforward of a C-shaped composite parts and warpage of a composite laminate isobtained. Then the impact of several parameters on curing deformation is discussed.At last, the control method of curing deformation is briefly stated. The results showthat fiber volume fraction, laminate thickness, volume shrinkage of resin and fiberdirection all play an important role on the warpage of the composite laminates, whilesome factors such as dwell temperature, cooling rate and thermal conductivity haveless effect on the springforward of C-shaped composite parts. For a particular materialand structure, symmetrical laminates can effectively reduce the warpage.