Experimental Study On Behavior Of Steel Concrete Composite Beams And Two Types Of Protection Armor Subjected To Drop Weight Impact

Since the 9.11 incident,the impact resistance of nuclear power plant against large aircraft such as commercial aircraft has appealed a high degree of attention in the field of nuclear safety.On the one hand,new nuclear power plants mostly use steel concrete composite structure as security shell,while the performance under impact loading of this kind of structure has not been totally understood,let along special instructions.On the other hand,active nuclear power plants were not designed to resist large projectile impact load,therefore our country's nuclear engineering research institutions proposed plug-in armor to improve the resistance ability of nuclear power plants against large projectile impact.This article studies the force performance of steel plate concrete composite structure through a series of static load test as well as low velocity impact tests,and at the same time,assesses the protective effect of two plug-in armor proposed by Shanghai Nuclear Engineering Research Institute through contrast tests.The main contents and results are as follows:In order to study the behavior of steel concrete composite beams,two groups of simply supported Steel concrete composite beams were used.One group was conducted for static load test and another group for drop impact test.During the static load test,vertical deflection,steel strains and concrete cracks were measured,and shear carrying capacity was obtained.Test results show that shear span to depth ratio directly influence the structural performance of the structures.During the impact test,signal of impact force,mid-span displacement,steel strains were measured.The failure process of beams during the test were captured by high-speed camera.This experimental study aimed at better understanding of the dynamic behavior of steel concrete composite beams under impact loading.These data can also be very helpful for improving the calculation accuracy of the theoretical calculation for beams under impact loading.Meanwhile,based on the theoretical and experimental research of the existing steel concrete composite beams,this paper simplifies the analysis the low velocity impact problem of simply supported steel concrete composite beams,a dynamic model is proposed.By comparing the calculated results with the experimental results,it is proved that the model can accurately calculate the deformation of the specimen.Four groups of quadrilateral simply supported slabs were designed to investigate the protective ability of two kinds of protection armor.One group was conducted for static load test and other three groups for flying projectile model impact test.The deflections and the crack development of the specimens in the static load tests were recorded,and ultimate load was obtained.The acceleration of the projectile model and the damage extent of the slabs were obtained in the flying projectile model impact test.The results showed that the shear thickening fluid armor could obviously absorb the kinetic energy of flying projectile model and could effectively reduce the peak acceleration of flying projectile object.On the contrary,the corrugated steel plate-foam aluminum armor hardly reduced the peak acceleration of flying projectile object,but could decrease the damage of the slab by reducing the damage of interface and increasing the working area of impact force.