Analysis And Experiment Study Of Lay-up Process Parameters Based On Carbon Fiber Prepreg Lay-up

Automated lay-up is of great importance to advanced composite manufacturing.The regulation of lay-up process parameters is an important part of automatic lay-up.The process parameters have important influence on the process performance of prepreg in the lay-up process,including the normal tack,tangential slipping behavior,deformation of prepreg and so on.The paper conducted a lot of experiment which can measure the process performance of prepreg.Effect of process parameters on the process performance about domestic prepreg were studied.Combined with the properties of cured composite laminates,the quality of automated lay-up can be evaluated systematically and appropriate lay-up process parameters can be confirmed.This paper is divided into six chapters,and the main contents are as follows:The first chapter briefly introduces the resin-based composites and automated lay-up technology for composite,focusing on the overseas and domestic research status about evaluating the quality of automated lay-up,the normal tack of prepreg,the tangential slipping behavior of prepreg,the predicted deformation of prepreg,the properties of cured composites.The background and significance of the research are expounded,and the main contents and framework of this paper are introduced.In Chapter 2,the lay-up test was used to simulate the lay-up process.Then the spindle peel test bed was established to explore the effect of process parameters on the normal tack between prepreg and mold,prepreg and prepreg,focusing on the lay-up tension and its influence mechanism.In the end,the normal tack results between prepreg and mold,prepreg and prepreg under various process parameters were contrastively analyzed.The suggestions about selecting process parameters were given and it is of great significance to control the normal tack in the lay-up process.In Chapter 3,the test device for measuring the curve of stress-displacement was conducted when prepreg slipped tangentially.Cohesive Zone Model was used to describe prepreg tangential slipping behavior quantitatively.The failure mode of tangential slipping behavior changed with lay-up temperature and separation velocity.Then,the microscopic mechanism was analyzed through comparison of micro-morphology on the prepreg surface.At last,the effect of lay-up process parameters on prepreg tangential slipping behavior was studied.The method is provided to test and characterize the tangential slipping characteristics of prepreg.In Chapter 4,the effect of lay-up process parameters on prepreg deformation was studied through experiment and simulation.Firstly,elastoplastic model is used to simulate the instantaneous viscoplastic deformation of prepreg.The mechanical properties of prepreg at various temperatures were tested and the deformation simulation of prepreg was established.Effect of lay-up process parameters on prepreg deformation was predicted.Then verification test was conducted.The simulation results were in agreement with the test results,which prove the validity of simulation.At last,the effect of gap produced in lay-up process on the lay-up quality was studied.It has a great significance of providing the prepreg gap in automatic lay-up.In Chapter 5,the rationality of the process parameter interval is verified by the performance of cured component.Firstly,the short beam shear test was conducted to obtain the relationship between failure load and lay-up process parameters.It was found that the lay-up pressure has the greatest influence on the interlaminar shear properties.Then,a numerical model of short beam shear test was established by using the progressive failure criterion.The influence of the interlaminar parameters on the load-displacement curve and the failure mode was studied.Combined with short beam shear test data,the relationship between interlaminar mechanical properties of cure composites and lay-up pressure was conducted.The influence of lay-up pressure on deformation of composite laminates and interlaminar failure mechanism was studied.It provides a significant reference for choosing the compaction force appropriately.In Chapter 6,the main content and innovation of this article are summarized,and the future work and research direction are discussed.