Explosive Dynamic Response And Design Method Of Explosion Resistance For Large-Space Steel Structure

Large-space steel structures have been greatly constructed recently as public buildings. They are crowded and are frequent target of terrorist attacks. Because of their long-span, complicated shape, concentrated distribution of natural vibration frequency and the particularity of blast loads, previous research and design method of explosion resistance have no application to large-space steel structures. So the paper discussed the research method of explosion resistance for large-space steel structure. By using this, a study of explosion resistance on an arch large-space structure was carried out. The main contents are as follows:By using LS-DYNA, the finite element model was presented for the simulation of explosion in air, the results showed a well consistent with empirical formula, the reliability of model and material parameter was proved, so the basis for numerical simulation of explosion in building was provided.After adopting these material parameters, the numerical simulation of explosion in an arch large-space structure was carried out, and the results showed that the research method and model were reliable. In view of the asynchronous pressure waveform of shock wave in deferent place, Proper Orthogonal Decomposition method (POD) was introduced, the problem of pressure distribution on structure was solved. By way of changing the parameters such as hole distribution on structure, rise-span ratio of structure, height of structure, TNT equivalence and position of explosion, the pressure distribution on arch large-space structure was investigated in different situation. Some reliable conclusions were gotten.After the impulse load on structure was defined, the paper studied the dynamic response of a single-layer reticular shell, which was a kind of arch large-space structure. The Ritz-POD method, which was proved to be efficient and precise by compared with the superposition method, was suggested to analyze the dynamic response of structure. Meanwhile, the shortage of Ritz-POD method was pointed out. The use point was that the ratio of Ritz vectors'number to eigenmodes'number should be larger. By way of changing the parameters such as rise-span ratio of structure, height of structure, TNT equivalence and position of explosion, the dynamic response of shell was investigated in different situation, then the reliable conclusions were gotten. According to it, suggestions about design method of explosion resistance were proposed.At last, recent design methods of explosion resistance for structure were presented. According to the upper research method and the characters of large-space steel structures, the design principles and methods for large-space steel structures were given.