Numerical Analysis And Calculation Research On The Damage Of Structural Targets

Frame structure buildings have been widely used as China’s urbanization process has accelerated over the years,but the impact of explosion loads was not considered in the design of frame structures in China.Research on the effect of internal explosions on frame structures is limited,so numerical analysis and calculation of damage caused by explosion loads on frame structures are of great significance.This article focuses on the research of the structural dynamic response and overall damage effect of frame structures under explosion loads.Based on existing explosion theory,numerical simulation was conducted using ANSYS/LS-DYNA software to analyze the structural dynamic response of different span layers of frame structures.The overall damage law of the frame structure and the determination method of the damage effect between different structures are obtained.It has certain reference significance for the application of overall damage assessment system,framework structure design and protective engineering.The main conclusions are as follows:(1)Through the simulated explosion loading test,the material constitutive model and various numerical simulation conditions suitable for reinforced concrete frame structure are verified and obtained.The evaluation proportions of each component in the frame structure under explosion damage and the overall damage evaluation method of the frame structure were obtained through AHP method and relevant literature fitting.Fuzzy vector single-value method can be used to compare and determine the degree of damage between different working conditions and it was divided into four intervals of 80,60,40,and 20,where a higher score indicates a lower damage effect.(2)When the frame structure is 7 layers and 7 spans,the structural stress generated by the explosion below is increased by 5.02×10~6Pa compared with other positions.When the frame structure is 7 layers and only changes the number of spans,the maximum structural stress is proportional to the increase in the number of spans,with a maximum increase of 15.8%.When the frame structure is 7 spans and only the number of layers is changed,the maximum structural stress is inversely proportional to the increase of the number of layers,and the maximum reduction is15.2%.(3)When the building is 7 layers and 7 spans only change the explosion position,the comprehensive evaluation score of the left room is 53.1015,and the comprehensive evaluation score of the bottom room is 58.106.The overall damage law is:left room>top room>middle room>bottom room.When the frame structure is 7 layers and only changes the number of structural spans,the damage effect is proportional to the increase of spans,while when the frame structure is 7 layers and only changes the number of layers,the damage effect is inversely proportional to the increase of layers.(4)The maximum mid-point displacement of beam and plate components in the same frame structure occurs at the top explosion,while wall and column components occur in the side room explosion.When the structure is 7 layers,the midpoint displacement of the plate component decreases with the increase of the number of spans,while the midpoint displacement of the beam component increases,and there is no obvious change in the column and wall components.When the structure is 7 spans,the midpoint displacement of the beam,plate,column,and wall components all decrease with the increase of the number of stories.