Elastoplastic analysis with fine beam model of vector form intrinsic finite element

A new fine beam model of vector form intrinsic finite element is proposed to conduct elastoplastic analysis of beams with different depth-span ratios. Vector form intrinsic finite element is a new structural analysis method to compute large deformation, collision, and fracture problems. The presented fine beam model is different from Euler beam or Timoshenko beam. The coupled effects of multifactor are considered in this new model, such as shear deformation, additional axial displacement induced by additional rotation of cross section, and additional transverse displacements considering bending stiffness reduction due to shear deformation. Applying to vector form intrinsic finite element analysis, the formula of strain and internal force of this new beam model is derived. The plane cross-sectional assumption is also modified when the material is at plastic stage. Using the proposed model, computer programs are developed by Fortran. Comparison between the computational results by present method and numerical or experimental results in the literature shows that the present fine beam model of vector form intrinsic finite element is more efficient and accurate when the analyzed beam has a large depth-span ratio and material is at plastic stage.