Research On Multi-scale Modeling Of Fibre Reinforced Composite Components Based On NURBS

As a result of high specific stiffness,high specific strength and designable characteristic,composite materials are widely used in the aerospace field.Composite components,whose structure has layered characteristics and material is uneven distribution,are integrally formed.This leads to not only poor design accuracy of the geometric model in the design process,which is hard to express the geometric reality,but also long development period.Moreover,there is a problem of transition from the design model to the analysis model,resulting in information disconnection in the batch analysis process.Aiming to solve these problems,this paper proposes a full life cycle isogeometric modeling method for the design and analysis of composite laminates,which uses NURBS as a mathematical structure,establishes a multi-scale geometric model of composite laminates,and reveals composite materials from macrostructure,mesoscale to microscopic material scale,in order to achieve structural and material design integration.Then an isogeometric analysis method for composite components is proposed,which realizes seamless connection from CAD to CAE,and develops a full life cycle isogeometric modeling simulation software system for composite material to verify the results of composite material modeling and simulation.Based on the design requirements of composite laminates,a full life cycle isogeometric modeling system framework for composite material integrated design and analysis is established.The design analysis process,which uses NURBS as a mathematical structure,is divided into conceptual model design,structural geometry model design,material geometry model design,and isogeometric finite element analysis.The multi-scale composite material conceptual model and geometric model integrated design and analysis is established to reveal the geometric reality of the components.Meanwhile,a method of isogeometric analysis of composite materials is proposed,which achieves the integration from CAD to CAE and realizes the full life cycle digitalization of composite design and analysis.The conceptual model of composite materials is based on product design requirements,while structural feature,material area distribution information and structural failure strength is extracted and parameterized.It lays the foundation for subsequent model design and analysis.After the structural delamination and material zoning characteristics of composite laminates are studied,a multi-scale geometric modeling method for composite laminates is proposed.From the macro scale,a geometric model of composite material structure based on the concept model feature lattice is established to express the product surface shape and meet the repetitive requirements of the design of the composite component’s shape.By taking the structural geometry model as the research object from the microscale and micro-scale,the material geometry model based on the material distribution information of the conceptual model is established.The stitch-stitching algorithm and the pre-embedded hole contour scanning algorithm based on T-spline are designed,and the transition layer-fitting modelling is performed on the laminated ply area of the composite material to realize highly realistic geometrical restoration of the production and use of composite materials.Finally,an integrated geometric model of structural and materials is established,and the integrated design of structural materials from macroscopic,mesoscopic to microscopic is completed.Based on the geometric model,a NURBS-based composite finite element analysis method is proposed.The mathematical model of the isogeometric analysis of composite materials based on the conceptual analysis model is established,the integrated geometrical model of the structural material is directly input,and the simulation analysis results are obtained to verify whether the design requirements are met.The isogeometric analysis of the composite material achieves the transition from CAD to CAE and accomplishes seamless integration.A full life cycle geometric modeling simulation software system for composite materials is developed.The system has completed the workflow that uses Paraview as the rendering core,and realized the conceptual model,structural model design,material model design,and geometric analysis design.The wing skin is used as an example to verify the feasibility of system’s modeling and simulation for composite materials.