Research on crashworthiness of thin-walled square tubes with diaphragms

The crashworthiness of thin-walled square tubes with diaphragms was analyzed by explicit finite element method. The results show that the tubes with diaphragms exhibit relatively stable crushing process. Under the quasi-static loads, the peak of initial compression force strengthens with the increase of the wall thickness, while the effect of the number of diaphragms on it is small. As wall thickness and diaphragm number increase, energy absorption, specific energy absorption and crush force efficiency of the structure are enlarged. The hardening coefficient in material model of Cowper-Symonds has no influence on the peak of initial compression force, but the energy absorption increases with the increase of the hardening coefficient β. Compared with β=1 and β=0, the energy absorption of structure increases by 8.97% at the crushing distance of 600 mm. Given the effect of strain rate, energy absorption compared with quasi-static situation is significantly improved. Meanwhile, at low impact speed, strain rate effect is more sensitive.