Collapse Analysis Of Light Steel Structure Subjected To Far-range Explosion

Recently,the chemical products for explosion occurred frequently,causing great economic losses and casualties.It can be found from the scene of the explosion that light steel structures which near the detonation are destroyed seriously or even collapsed subjected to blast load.Therefore,the destruction level caused by blast would be mitigated through studying the explosion resistance of structures.In this dissertation,three main problems are studied.They are(1)simulation of interaction between blast wave of far-range explosion and light steel structure;(2)analysis the distribution of blast load and derivation of the formulae to estimate blast loads action on the front and the top of the light steel structure;(3)dynamic responses and collapse processes of portal steel frame,plane truss and space truss subjected to far-range explosion.More detailed introduction are presented as the following.(1)The Remap tool in AUTODYN is used to simulate the propagation of blast wave by dividing the analysis into two individual steps.Establish numerical model of interaction between blast wave of far-range explosion and light steel structure.Compare the result of numerical simulation with the test data of UFC3-340-02,and validate the correctness of numerical model.(2)The blast load and its distribution action on the front and the top of light steel structure are analysed.The results show that there is a core region within the front of the structure.In this region,the intensity of the reflected wave is high,and the change of peak pressure and positive specific impulse are small.Based on it,the prediction formulas are proposed to estimate the blast peak pressure,positive specific impulse,and the arrival time of the front surface of the blast wave on both the front and top of the light steel structure.A simplified model of blast load for dynamic responses analysis of light steel structure subjected to far-range explosion is proposed.(3)The dynamic responses and collapse processes of portal steel frame subjected to far-range explosion are analysed.The dynamic response of the portal steel frame subjected to far-range explosion under different proportional distances is analysed by controlling the actual explosion distance and explosive equivalent respectively.Summarized the damage patterns of portal steel frame subjected to the explosion,and the weak part of portal steel frame is found out.The improvement suggestion for designing portal steel frame is proposed.The dynamic response of the portal steel frame with windows subjected to far-range explosion is analysed and compares with the windowless portal steel frame.(4)The dynamic responses and collapse processes of plane truss and space truss structure subjected to far-range explosion are analysed.The weak part of plane truss is found out,and the improvement suggestion for designing is proposed.The damage patterns of plane truss and space truss are summarized.