Lateral compression behaviors of thin-walled equilateral triangular tubes

The paper deals with one important topic in impact engineering - the lateral compression behavior of thin-walled tubes. To study the lateral collapse modes and energy absorption behaviors of equilateral triangular tubes, quasi-static compression experiments were carried out. Crushing modes were revealed by the experiments. Three typical crushing stages characterize the lateral deformation plateaus of equilateral triangular tubes. In simulation, perfect tubes have symmetrical crushing modes. Strengths of the tubes were correctly predicted by the competition between yielding and buckling. Based on the observed crushing modes, plastic models were proposed for each stage to predict the lateral crushing behaviors theoretically. Equilateral triangular tubes have unified energy absorbing mechanisms, including five plastic hinges and one traveling plastic hinge. Plastic models have been constructed to predict the mean crushing forces and evaluate the energy absorption efficiency of the equilateral triangular tubes.