Study On Dynamic Response Of Prefabricated Reinforced Concrete Laminate Slab Under Blast Loading

In today ’s world,frequent terrorist attacks and accidental explosions have brought great challenges to engineering structures.In recent years,with the rapid development of urbanization and the increasing requirements of building industrialization,our government has introduced relevant policies to promote the application of prefabricated structures.As an important component of the prefabricated building structure,laminated slabs are prone to local or overall collapse in the event of serious damage.Most of the research on prefabricated structures focuses on the seismic evaluation of connection nodes,and there are relatively few studies on its antiexplosion performance.Laminate slabs will play an important role in the development and construction of prefabricated buildings.In this paper,the dynamic response and anti-explosion performance of prefabricated reinforced concrete laminated slab are studied by means of explosion test and numerical simulation.The main research work and results are as follows:(1)An anti-explosion test device was designed and fabricated.The device can not only transmit the load,but also resist the side flow of the blast shock wave.(2)The explosion tests of prefabricated reinforced concrete laminate slabs and cast-in-place slabs under different blast loading have been conducted.The test results show that when the blast loading is small,the deformation and damage characteristics of the laminate slab are weaker than those of the cast-in-place slab,and the bending resistance of the laminate slab is better than that of the cast-in-place slab.With the increasing blast loading,the deformation and crack development of the laminate slab are higher than that of the cast-in-place slab,and the overall bending resistance is weakened.(3)Based on the LS-DYNA software,the explicit dynamic analysis of the explosion test is carried out,and the crack development,deformation and failure mode of the prefabricated laminate slab under the blast loading are obtained.The results are compared with the test results to further verify the reliability of the finite element analysis.(4)Twenty conditions with different TNT equivalents were designed and numerically analyzed,and the difference of anti-explosion performance between castin-place plate and laminated slab was obtained.The specimens under different charge weight all showed overall bending failure,and the mid-span area under larger charge weight was also accompanied by local failure of concrete shedding.(5)Considering the compressive strength of cast-in-place layer and precast layer concrete,steel yield strength,slab thickness,reinforcement ratio,steel structure form,laminate slab interface position and other factors,the finite element parameter analysis is carried out.The results show that the anti-explosion performance of prefabricated reinforced concrete laminate slabs can be improved by increasing the compressive strength of concrete,the yield strength of steel bars,the reinforcement ratio or the thickness of slabs.The optimal requirements of interface position and reinforcement structure are given.