A NEW STRAIN-BASED TRIANGULAR ELEMENT FOR 2D STRUCTURAL ANALYSIS

ABSTRACT: This work presents a novel strain-based finite element formulation specifically designed for the comprehensive analysis of two-dimensional structures under static and dynamic elastoplastic conditions. The proposed triangular element features three degrees of freedom per node, including two in-plane translational components and one rotational component about the normal axis.The displacement field is derived from predefined strain functions that satisfy the compatibility equations, while the interpolation functions are carefully constructed to provide an exact representation of rigid body motions. The developed formulation is applicable to both static and time-dependent elastoplastic analyses.In the static case, the element accurately determines nodal forces, displacements, and stress distributions. For dynamic analyses, a lumped mass matrix combined with an explicit time integration scheme is adopted to improve computational efficiency.The accuracy and robustness of the proposed element are validated through several benchmark test problems, demonstrating its excellent numerical performance and reliability in structural analysis.