Quasi-static experimental and nonlinear finite element analyses are performed to compare the energy absorption and initial peak load of combined circular and square sections with those of regular circular and square sections. The combined circular and square sections have higher energy absorption and lower initial peak load. These tubes can be widely used to ensure passenger safety in automotive and aerospace landing structures. The predicted numerical crushing load and fold pattern are in good agreement with experimental results. The specific energy absorption capability of the combined tube is significantly higher than that of the square tube and is close to that of the circular tube. The initial peak load of combined tube is significantly lower than that of the circular tube and somewhat lower than that of the square tube. Changing the section dimensions and their length results in higher energy absorption of the combined section than that of circular and square sections. Moreover, the initial peak load in the combined section is lower than that of the circular and square sections in all cases. © 2014 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.