Research On Multi-scale Virtual Testing And Model Reusing Of Composites Structures

Composite material,as a kind of excellent properties materials, has been widely used in the field of aerospace, aviation, etc. Composite structures have a variety of geometric forms.Now the rationality of composite structures design mainly rely on building-block test, and it resulted in the long period for design and parameter modification, poor reusability and so on. Virtual testing couples computational simulation techniques, physical testing methods, multi-scale testing method and analysis theory, which only requires a few experiments can greatly shorten the design and development cycle and reduce development costs by using computer to complete partial test.Virtual testing combined with model reuse technology can improve the defects of poor reusability,realize parameters mapping between model design and analysis by parametric driven,complete the rapid transition form concept design to final test.On the basis of research composite structures in multi-scale virtual test and model reuse technology results at home and abroad, the paper mainly studied composite structure design process and design index and then proposed multi-scale engineering algorithm and finite element calculation method,established the model reuse and parameter adjustment method, developed an virtual test system software platform.On the basis of the analysis of the composite structure virtual test and model reuse technologies,summarized the design process,verification index,reuse factors and adjustment parameters. The paper designed the system framework which include engineering algorithm,finite element calculation,model reuse and support database,at the same time the paper given the the system reuse object model.A multi-scale engineering algorithm method which considered fiber defects for the preliminary design of composite structures was presented. The overall block diagram of engineering algorithm designed based on establishing the calculation method for the multi-scale geometric configuration of composite materials.Established RVE model of folded fiber and predicted engineering constants of composite the by the normal distribution of the fiber fold angle.Given the predicted intensity spectrum about simple planes by different failure criterion according to the engineering constants. Established the buckling analysis model about the simple plane and stiffened plane and given the relationship between buckling loads and the parameters of structure. Realized the fast analysis to the preliminary design model and select to the design scheme by parameterdriven.A multi scale finite element analysis method which is for the design strength and buckling load of structural members was presented.Comprehensive consideration of design model and analysis model interaction method, design parameters adjustment,damage process simulation program, etc. Studied the parameter mapping method of CAD/CAE model and realized quick build model from designing to analysising.Presented the finite element progressive damage model which using the principle of stiffness softening. Presented the discrete model of the folded fiber which predicted the weak points of the macro structural from points of view of mesoscopic. Established a spectrum analysis method about the buckling load and the influence parameters of laminated plates with holes and stiffened plates and realized the parameters mapping between design and analysis.Verified the correctness and feasibility of the finite element analysis method by comparing results of the analysis and the experimental.Model expression, retrieval and parameter adjusting method which considered the low reusability and the difficulties in adjusting design parameters was presented.Builded model storage mode and model library access path based on the similarity of model structure,properties and functions. Established the spectral analysis of the buckling load and the geometrical parameters of the model and realized fast calculation from the index parameters to the structure parameters. Established the relationship between the strength and the shop floor based on improved genetic algorithm. Reasonable adjustment of laying parameters by engineering algorithm and finite element calculation.Based on the above technique, the system structure and technical process of virtual test system software platform of composite stiffened panel was designed. Set up the system function model, and completed the interface design between the system and the relevant software. The system development was completed with VC++. The supporting database and knowledge base of virtual testing was established. The integration of engineering method, virtual test and physical test was realized in this system. The feasibility of the system was validated by Some examples of virtual testing.