Collision performance of square tubes with diaphragms

•Energy absorption properties of tubes with diaphragms have been investigated experimentally and numerically.•The tubes with diaphragms exhibit relatively stable crushing process.•The buckling mode of the specimen is strongly related to the process errors.•The dynamic response of tubes with diaphragm is more sensitive to strain rate effects.

The energy absorption responses of conventional tubes and tubes with diaphragms are analysed here by means of finite element simulation. Numerical results show that tubes with diaphragms exhibit a relatively stable crushing process. The effect of imperfect energy absorption responses is also analysed, including the top shape of tubes and oblique loading. The strain rate affects the dynamic response of tubes with diaphragms. Four prototypes of these tubes were constructed and tested; however, sizeable differences were obtained between experimental results and the results of numerical simulation of the ideal structure in terms of process errors.