Research On Temperature Field Simulation And Structure Improvement Of Autoclave Forming Mold For Composite Material

During the curing of composite material in the autoclave,the uniformity of the temperature has a vital important effort on the product quality.In this paper,the temperature distribution in the curing processing of composite materials is studied.By improving the mold design,to improve the temperature uniformity of components.In this paper,the temperature field inside the autoclave was simulated by finite element method and it is verified by the known experiment data.Through the simulation analysis,the mold surface temperature is ladder-type distribution.Then,comparing the cure degree of the material at different positions of the mold,the result shows that the smaller the temperature difference of the mold surface,the smaller the cure gradient.In order to improve the temperature uniformity of the mold,simulating and redesigning the mold plate and the support structure.For the mold plate: According to the characteristic that the thermal resistance is proportional to the material thickness,designing the trapezoid plate,ladder-typed plate and function-typed plate.The simulation results show that: the variable thickness plate can greatly improve the mold surface temperature uniformity.The trapezoid plate reduces the temperature variance and the maximum temperature difference by 80.38% and 34.73% respectively;The ladder-typed plate reduces the temperature variance and the maximum temperature difference by 73.66% and 41.31% respectively;The Continuous thickness changed plate reduces the temperature variance and the maximum temperature difference by 83.90% and37.72% respectively.For the mold support structure: Under the premise of ensuring the stiffness requirement of the mold,the influence of the shape of the cooling holes,the thickness of the support plate,the vertical distance of multi-molds and support structure on the surface temperature is taken into account.The simulation results show that: The mold with square cooling holes is the most uniform in temperature distribution,but the structural rigidity is worse than the diamond and circular cooling holes;When the thickness of the support plate is thinner,the temperature distribution of mold is more uniform.Meanwhile,temperature uniformity is more sensitive to the thickness of the support plate perpendicular to the wind direction than the plate parallel to the wind direction;When the vertical distance of multi-mold is smaller,the mutual influence between molds becomes larger,the temperature uniformity and the ability to increase temperature decrease;Compared with the frame support structure,the skeletal support structure can provide a more uniform distribution of temperature,in the same maximum lifting deformation requirement.