| At present,there are frequent incidents of damage to the building structure due to accidental impact every year,and the installation of protective wall s or panels for important building structures is an effective way to prevent damage to the building.At present,the engineering community often adopts the steel-concrete-steel composite structure(SCS composite structure)as the protective wall s or panel,but how to further improve the static and impact resistance of the SCS structure is still a current research hotspot.To this end,this paper proposes a new type of multi-cavity steel-concrete sandwich panel,and experiments,theoretical analysis and finite element numerical simulation were employed to study its static and impact resistance.The research content is as follows:(1)Ten multi-cavity steel-concrete sandwich panel are designed and manufactured,and the four point bending test under static action is carried out.The loaddisplacement and strain response curves,stiffness characteristics,bearing and deformation capacity of the composite panel were obtained.The failure mode,the strain characteristics of the steel plate and the influence of parameters on the static performance are analyzed.The test results show that: under static load,the failure mode of the composite plate is bending failure;the thickness of the steel plate has a greater impact on its bearing capacity,and the elastic stiffness will be a ffected by the shear-span ratio.However,the change of stud spacing and loading direction has no obvious effect on the bearing capacity and stiffness.(2)Based on the assumption of a plane section,the theoretical formulas for the yield and ultimate flexural bearing capacity of the multicavity steel-concrete sandwich panel are established.The results show that the theoretical calculation formula of the bearing capacity proposed in this paper is in good agreement with the test results,which verifies the rationality of the theoretical formulas.(3)Based on the ANSYS/LS-DYNA finite element analysis software,the finite element analysis of the multicavity steel-concrete sandwich panel under static force was carried out.Parameter analysis is carried out on the basis of verification of numerical model and experimental results.The analysis shows that the change of steel plate thickness and shear span ratio will affect the stress distribution of each part of the composite panel under static load and the equivalent plastic strain distribution of concrete,while the change of stud spacing basically has no effect.The distr ibution of the high-stress area of the ribs will change when loading on the reverse side.The local buckling of the composite plate is more serious,and the rib part will bulge along with the upper steel plate.(4)Using ANSYS/LS-DYNA finite element software,the failure mode and dynamic response process of multicavity steel-concrete sandwich panel under impact load were studied.At the same time,the impact law of steel plate thickness,stud spacing,impact direction,hammer head quality,impact speed,impact momentum and impact kinetic energy on the impact force,hammer head displacement,bottom plate center displacement,and energy of each part of the structure is analyzed and summarized.The results show that the composite panel presents an overall bending failure mode under the impact load,and the hammer head position is partially sunken,accompanied by the crushing and cracking of the concrete.(5)The lower steel plate and concrete part are the main components that resist impact and dissipate energy.Increasing the thickness of the steel plate can improve the impact resistance of the composite panel,but the change of the stud spacing and the impact direction has little effect on the impact resistance of the composite panel.When the impact velocity is the same,the increase in the hammerhead mass is linear with the impact response.When the hammerhead mass is the same,the impact velocity and the impact response no longer show a linear change.When the impact kinetic energy is the same and the impact momentum is small,the impact response of the composite panel and the energy absorption effect of each part will be affected by the impact momentum.But the impact is no longer significant when it is too large.When the impact momentum is constant,the increase in impact kinetic energy will lead to an increase in inertial force peak and energy absorption,and will reduce the peak impact force. |
