A methodology for evaluating dynamic responses of steel columns subjected to blast load under different situations

摘要

In recent studies, the uniform simplified distribution blast load and numerical simulation have proven to be prevalent in the use of investigating structural components dynamic behaviour during blast events, whilst neglecting the negative phase pressure. This study compares the steel column's response during the total pressure period to that of its response during only the positive stage. Moreover, the real blast pressure has varying values depending on the point distance and explosion incident angle. The real blast load curve was derived by using a specialised program to calculate pressure at different points on the steel column vertical line; and the results were used to compare its impact with the uniform and concentrated cases. Also ABAQUS finite element code was used to check the validity of the single-degree-of-freedom (SDOF) analysis method when the column is subjected to axial and transverse blast loads. The obtained results show the SDOF inability through dynamic reaction calculations. In addition, SDOF has limitations in dealing with dynamic steel response when the axial load ratio was greater than 0.5. Damage prediction methods and equations were introduced through different concepts and the ductility ratio was used to estimate the damage level of 100 kg TNT at 4.5 m stand-off distance. The strain rate effects were included in the material with different scenarios based on the dynamic increase factor.