Three-bar truss

This problem contains basic test cases for one or more Abaqus elements and features.

This page discusses:

ProductsAbaqus/Standard

Elements tested

  • T2D2
  • T2D2H
  • T2D3
  • T2D3H
  • T3D2
  • T3D2H
  • T3D3
  • T3D3H
  • FRAME2D
  • FRAME3D

Problem description



Material:

Linear elastic, Young's modulus = 30.0 × 106.

Boundary conditions:

Nodes A, B, and C are pinned.

Loading:

FyD=​ −10000.0.

Reference solution

uyD=​ −1.3711 × 10−2, σ=​ 32907 in elements 1 and 3, σ=​ 41134 in element 2.

Results and discussion

All elements yield exact solutions. Multi-point constraints are required to eliminate singularities in the three-node element tests using truss elements; e.g., T3D3.

The frame elements tested have rectangular cross-sections with the same cross-sectional area as the truss elements tested. In the cross-section for frame elements, pinned connections are specified for the ends of the frame elements by declaring the relevant parameter for the frame section. The joints are thus characterized by pinned connections. Since the frame elements are formulated in terms of section properties, stress output is not available; instead, the section forces are available. Stresses calculated from the axial force and the cross-sectional area match the stresses obtained from the truss element tests.