Influence Of End Restraints On Beam Members Under Blast Loading

Reinforced concrete beams are widely used in construction.The study of the failure characterization of typical beam members under blast loads is of great significance for the anti-explosion design and post-explosion damage assessment of buildings.This paper mainly focuses on the deformation and failure of beam members under the action of explosion loads in practical engineering,considering the influence of end restraints on the deformation and failure of members,and studies the relationship between beam member deformation and beam end stiffness and the effect of beam end rotational stiffness on the change of beam end rotational stiffness.The effects of local and global failure of components.The contents of this paper could be presented as follows:(1)The calculation method of explosion load on member surface is summarized.Load by reading the literature,summarize the previous research results,briefly describe the research status of reinforced concrete beam members under strong dynamic load,and summarize the calculation method of relevant parameters of explosion load and the equivalent method of component surface load.(2)Analysis of related properties of beam members.The research conditions are determined by consulting the current relevant codes and the arrangement of beam members in the actual frame structure engineering;the damage and failure models of concrete and steel bars under explosion loads are briefly introduced.Combined with practical application,the failures of components and functions of reinforced concrete beams under explosion loads are analyzed.(3)Experiment and model parameter verification.In the display dynamics analysis software LS-Dyna,select the appropriate algorithm and the material model required for the calculation,determine the material parameters,and use the test to verify the validity of the selected material model and the numerical simulation results.Composition of cross-sectional damage under blast loading.(4)Numerical simulation research.After determining the material parameters required for numerical simulation,firstly,the member deformation is selected as the failure characterization,and the influence of member surface load form on member deformation is studied.Secondly,the rotation stiffness of the beam end is changed by adjusting the length of the outrigger at the beam end of the test beam,and then the maximum displacement of the member and the overall and local damage of the member are studied by numerical simulation.In this paper,the deformation of the member under the close-range explosion is studied,and the relationship between the load form of the member and the deformation shape of the member under the load under different proportional distances is obtained.At the same time,the influence of the rotational stiffness of the beam end on the deformation and local failure of the member under blast load is studied.It has a certain reference value for the anti-explosion design of components and the prediction of post-explosion damage.