Thermoforming Of Thermoplastic Glass Fiber Reinforced Polypropylen Research And Simulation Analysis On The Formability

Light-weight composite materials are an important means of light-weighting automotive bodies.Because of its recyclability,thermoplastic composites have attracted a wide range of interest from researchers and automakers over automotive thermosetting composites.Balanced cost performance,glass fiber reinforced polypropylene composites is currently the most considered one of the automotive lightweight components development.However,for the continuous fiber reinforced type(CFRTP)of this material,the formation mechanism and control method corresponding to the hot-press forming defects are still not clear.Therefore,glass fiber reinforced polypropylene composites were studied as the object of study in this paper,the effects of the forming temperature on the forming character istics of the material were studied,and the sensitivity of the forming defects to the forming characteristics parameters was analyzed,and provide guidance for the design and development of the above materials used in the product,the specific research co ntent is summarized as follows.(1)Research on the influence of temperature on the forming of characteristics of hybrid materials: based on the generalized variation of the material temperature in the forming process,the bending and off-axis shearing characteristics of the glass fiber reinforced polypropylene composites were mixed at different temperatures.The results show that the parameters of the bending and shearing properties of the material are greatly affected by temperature,and the tensile prope rties are very little influenced by the temperature.(2)Half dome of hot-press forming study: selecting typical half dome shape features and designing corresponding thermal model forming experimental mold,taking the forming temperature as a variable,the influencing mechanism and law of the thermoplastic material's formability were explored.The results show that the forming temperature has a significant effect on the shear angle and the distribution characteristics of the wrinkles.The number of formed wrinkle defects decreases with the increase of the current forming temperature setting.(3)Parameter sensitivity analysis: firstly,the semi-domed mold forming analysis model was established based on the experimental conditions and the viscoelasticity constitutive model,and the accuracy was verified by comparing the experimental results.Then,based on the generalized variation range of the material parameters under the influence of the measured temperature,the DOE methodology was used to explore the sensitivity of the forming defect rate to the flexural modulus,shear modulus and shear angle of the material forming parameters,and a corresponding regression model was established.The results show that the combined effect of bending stiffness,shear angle and shear modulus has the greatest influence on the formation of wrinkle defects.This also implies that the appropriate molding temperature control for molding parameter changes will effectively reduce the occurrence of molding defects,thus providing an effective reference basis for the design and system of subsequent related parts and components.