Curing Deformation Analysis Of Complex Composite Cylinder Structure

Composite materials for its light weight,superior strength characteristics of widely used in aerospace and other fields,however,composite materials through high temperature curing in forming and cooling process,due to thermal expansion and contraction of materials , chemical reaction resin matrix shrinkage effects,and composite materials and forming mold material used in the thermal expansion coefficient significantly different,composite materials at room temperature under an ideal free-form shape with the expected inconsistencies that may arise between the state of composite,cure deformation of the component form the connection between accuracy and matching components will have very adverse effects. Composite cylinder widely used in aerospace field,and its complex structure for the cylindrical shape,with ribs inside,cylindrical structure along the side of the centerline of a number of openings. For the complex structure of industrial usually soft membrane assisted RTM process forming,as the curing temperature distribution is essentially a nonlinear heat source of the heat conduction problem,One of the heat from the exothermic chemical reaction resin. Exothermic reaction can lead to higher local temperature composite materials,which form a complex temperature gradient,the results will lead to non-uniform curing. Non-uniform curing can lead to the development of residual stress,after stripping the role of residual stress will lead to structural deformation,many factors can affect the residual stress, such as structural non-symmetry,layer and process control,curing systems and so on,but mold and composite thermal expansion coefficient mismatch is affecting the main factor,so this article in the complex structure of composite cylindrical objects,Deformation of composite materials made curing step by step from simple to complex hierarchical modeling approach,by unidirectional composite plate embedded fiber Bragg grating to measure the strain,application of the equivalent thermal expansion coefficient of the method,analysis of the deformation caused by residual stress,by experimental results compared with finite element analysis to verify the effectiveness of the proposed method.In this paper,the structure of complex composite cylinder that is the main factor deformation of the structure of non-symmetry,layer form and mold deformation on the deformation of composite materials were analyzed,by Finite element simulation method,the mold deformation as a displacement load,calculated deformation of the cylinder which caused by mold deformation. In addition,the cooling stage in curing the structural factors is considered,by finite element method simulation example,change the structure of layers and the structure of non-symmetry structure gives less deformation,the above results of the composite material cylinder can guide mold design,to control mold deformation,or offset the impact of deformation on the component to provide theoretical support...