| Reinforced concrete structures may be subjected to accidental impact during normal service,and continuous collapse may occur under impact.Therefore,it is necessary to do more research and Analysis on the response performance of reinforced concrete structures under impact load and the continuous collapse performance of structures.In this paper,the impact resistance and continuous collapse resistance of reinforced concrete shear walls are discussed.The main research work is as follows:(1)Finite element model is established by ANSYS/LS-DYNA to simulate the drop-weight impact test of existing reinforced concrete beams and slabs and the pendulum impact test of reinforced concrete shear wall,which verifies the feasibility of the material model and model established in this paper.(2)The finite element model of reinforced concrete wall is established.The effects of axial compression ratio,wall width and edge members on the impact resistance of reinforced concrete walls are analyzed.The results show that with the increase of the axial compression ratio,the impact resistance of the wall is improved,and the damage area of the wall with axial compression is concentrated;the impact resistance of reinforced concrete wall can be improved by increasing the wall width;and the restraint of the edge component on the middle part of the wall can be strengthened to increase the impact resistance of the wall.On this basis,the three stages of the wall under the ultimate load are analyzed,and a criterion for judging the failure of the wall under the ultimate load is proposed.The influence of the axial compression ratio,the wall width and the edge members under the ultimate load is analyzed by using the criterion proposed.The results show that when the impact mass is constant,the impact energy required for structural failure decreases with the increase of the axial compression ratio.(3)The finite element model of single reinforced concrete frame is established.The numerical simulation of the pull-out column of the model frame can reflect the collapse process of reinforced concrete frame structure.Combining with the model validation of the impact test of reinforced concrete members in the previous paper,the numerical simulation of the impact load acting on the frame and the continuous collapse of the shear wall is guaranteed.Effectiveness.The impact simulation of reinforced concrete columns at different locations is carried out,and the collapserange of reinforced concrete frames is different at different locations.The differences between impact simulation and pull-out simulation are analyzed.The numerical simulation of reinforced concrete columns with infilled stirrups is carried out again,and the results show that infilled stirrups can increase the impact resistance of members.And the collapse resistance of the structure.(4)The response of shear wall under gas explosion is simulated by applying uniform load.A four-storey reinforced concrete shear wall model is established and the continuous collapse performance of the structure is analyzed.Based on the analysis results,the following main conclusions are drawn: gas explosion in cast-in-place reinforced concrete shear wall structure will not cause gas explosion.The failure of the wall results in the continuous collapse of the structure,so the effect of gas explosion can not be considered separately in the design of cast-in-situ shear wall structure.When the bottom Q18 is removed alone or Q18 and Q19 are removed,the stress transfer mainly passes along the upper three-storey Q18 with high stiffness to the wing walls on both sides,while the stress transfer to other components is less.When the bottom three-sided wall is demolished,the continuous collapse occurs in the middle part of the wall under the action of the load with the axial compression ratio of0.6.Because the shear wall structure has great lateral stiffness in both directions,the reinforcement in the beam and slab in the middle area can not collapse and destroy the surrounding area until it is pulled off.In the process of collapse of shear wall structure,there is also a process of transformation from "arch action" mechanism to "suspension action" mechanism. |
