Development Of Structural And Failure Analysis Function For Composite Based On SiPESC

Composite materials are widely used in aerospace,mechanical and other engineering fields because of their greater specific stiffness and specific strength than metal materials,excellent designability and low cost.With the increasing application,the mechanical analysis of composite materials has become an important topic.As a numerical method with the most mature theoretical development and high reliability,the finite element method is widely used in the field of structural engineering.This resulted in some finite element softwares such as Ansys and Nastran.These finite-element-software currently include relatively complete composite-related static,dynamic,instability,and failure strength checks.In order to improve and improve the analysis ability of SiPESC composite material shell structure of domestic autonomous finite element software,this paper completed the following research and development work based on SiPESC.FEMS:(1)As the basis of the composite element,two kinds of non-conforming membrane element with rotational degrees of freedom,and three nodes and four based on first-order shear theory were developed.The gusset element is combined into four different types of shell elements by membrane and plate elements.Some important technologies of finite element processing of plate and shell structural element are adopted,including non-conforming technology to deal with the in-plane self-locking of the membrane element;the mixed interpolation technology is used to solve the lateral shear self-locking of the plate element and the four-node shell element warpage.By adding the in-plane rotational degrees of freedom of the small and Allman forms,SiPESC can analyze the large-scale complex beam-shell structure combination problem.(2)Based on the general-purpose plate and shell element developed above,both threenode and four-node laminate composite elements were developed.By using a variety of composite material element processing techniques,including the transverse shear strain energy equal principle to calculate the transverse shear coefficient of the constitutive matrix of the laminate,it is possible to calculate the constitutive matrix of different layup modes such as symmetry,asymmetry,and offset;The pure bending hypothesis corrects the transverse shear stress,compensates for the shortcoming of the first-order shear theory that the transverse shear stress is constant,improves the calculation accuracy of the stress,and paves the way for the failure calculation.(3)Developed the self-vibration and buckling stability analysis functions of the composite structure,and provided the calculation of the composite element mass matrix and the stress stiffness matrix.Based on this,the power problems such as frequency response and random vibration of the composite structure can be further expanded and considerations The analytical ability of the actual problem of stress,and provides some calculation data that can not be provided by commercial software,such as stress stiffness matrix extraction,etc.,provides technical support for structural topology optimization design,and reflects the openness of domestically controlled software.(4)The composite material strength failure check framework was constructed,and the Tsaiwu criterion of three-dimensional stress and the failure module of the maximum stress criterion were developed.In order to meet the needs of different users and the diversity of actual engineering,a framework for users to define the failure criteria through redevelopment is constructed to improve the practicability and versatility of the SiPESC composite failure module.It also provides post-processing visualization functions such as composite layer stress and failure coefficient,which is convenient for viewing the calculation results of the layer.Through a series of practical engineering shell and shell and composite materials,the paper compares with the current general commercial software.The calculated functions are all consistent with the commercial software,which proves the correctness of the program.