Current practice in analysis and design of blast doors subjected to blast loading considers only simple boundary conditions and material properties. The boundary conditions and material properties, in fact, have consi...Current practice in analysis and design of blast doors subjected to blast loading considers only simple boundary conditions and material properties. The boundary conditions and material properties, in fact, have considerable influence on the response of blast doors subjected to blast loading. In this paper, the dynamic responses of a reinforced concrete arched blast door under blast loading were analyzed by the finite element program ABAQUS, combined with a previously developed elasto-viscoplastic rate-sensitive material model. And the effect of the surrounding rock mass and contact effect of the doorframe were also taken into account in the simulation. It is demonstrated that the strain-rate effect has considerable influence on the response of reinforced concrete blast door subjected to blast loading and must be taken into account in the analysis.展开更多
This paper mainly investigates the effects of initial static shear stress and grain shape on the liquefaction induced large deformation of saturated sand under torsional shear.Nanjing sand,mainly composed of platy gra...This paper mainly investigates the effects of initial static shear stress and grain shape on the liquefaction induced large deformation of saturated sand under torsional shear.Nanjing sand,mainly composed of platy grains,is tested with different initial static shear stress ratio(SSR)using a hollow column torsional shear apparatus.The tests find that the saturated Nanjing sand reaches full liquefaction under the superposition of initial static shear stress and cyclic stress for both stress reversal and non-reversal cases.However,it requires a large number of loading cycles to reach full liquefaction if stress reversal does not occur.With increasing the initial static stress,the large deformation of the Nanjing sand should mainly induced by the cyclic liquefaction firstly under a smaller initial shear stress,and then it should be induced by the residual deformation failure.The critical point occurs approximately when the initial shear stress is close to the amplitude of the cyclic shear stress.Meanwhile,it shows that grain angularity increases the liquefaction resistance when the initial static shear stress is zero.A small initial static shear stress causes the larger loss of liquefaction resistance for angular sand than rounded sand.At a high initial SSR,the angular sand is more resistant to the large residual deformation failure than the rounded sand.展开更多
基金Supported by National Natural Science Foundation of China(No.50525825)
文摘Current practice in analysis and design of blast doors subjected to blast loading considers only simple boundary conditions and material properties. The boundary conditions and material properties, in fact, have considerable influence on the response of blast doors subjected to blast loading. In this paper, the dynamic responses of a reinforced concrete arched blast door under blast loading were analyzed by the finite element program ABAQUS, combined with a previously developed elasto-viscoplastic rate-sensitive material model. And the effect of the surrounding rock mass and contact effect of the doorframe were also taken into account in the simulation. It is demonstrated that the strain-rate effect has considerable influence on the response of reinforced concrete blast door subjected to blast loading and must be taken into account in the analysis.
基金supported by the National Natural Science Foundation of China(Nos.51778290,51778386)the National Science Fund for Distinguished Young Scholars(No.51725802)the Natural Science Foundation of Jiangsu High School(No.16KJA560001)。
文摘This paper mainly investigates the effects of initial static shear stress and grain shape on the liquefaction induced large deformation of saturated sand under torsional shear.Nanjing sand,mainly composed of platy grains,is tested with different initial static shear stress ratio(SSR)using a hollow column torsional shear apparatus.The tests find that the saturated Nanjing sand reaches full liquefaction under the superposition of initial static shear stress and cyclic stress for both stress reversal and non-reversal cases.However,it requires a large number of loading cycles to reach full liquefaction if stress reversal does not occur.With increasing the initial static stress,the large deformation of the Nanjing sand should mainly induced by the cyclic liquefaction firstly under a smaller initial shear stress,and then it should be induced by the residual deformation failure.The critical point occurs approximately when the initial shear stress is close to the amplitude of the cyclic shear stress.Meanwhile,it shows that grain angularity increases the liquefaction resistance when the initial static shear stress is zero.A small initial static shear stress causes the larger loss of liquefaction resistance for angular sand than rounded sand.At a high initial SSR,the angular sand is more resistant to the large residual deformation failure than the rounded sand.
