For a building structure subjected to impulsive loading, particularly shock and impact loading , the response of the critical columns is crucial to the behaviour of the entire system during and after the blast loading...For a building structure subjected to impulsive loading, particularly shock and impact loading , the response of the critical columns is crucial to the behaviour of the entire system during and after the blast loading phase. Therefore, an appropriate evaluation of the column response and damage under short-duration impulsive loading is important in a comprehensive assessment of the performance of a building system. This paper reports a dynamic analysis approach for the response of RC columns subjected to impulsive loading. Considering that the dynamic response of a column in a frame structure can also be affected by the floor movement which relates to the global vibration of the frame system, a generic column-mass model is used, in which a concentrated mass is attached to the column top to simulate the effect of a global vibration. To take into account the high shear effect under impulsive load, the model is formulated using Timoshenko beam theory, and three main nonlinear mechanisms are considered. Two typical scenarios, one under a direct air blast loading, and another under a blast-induced ground excitation, are analyzed and the primary response features are highlighted.展开更多
The transient response of an unlimited cylindrical cavity buried in the infinite elastic soil subjected to an anti-plane impact load along the cavern axis direction was studied.Using Laplace transform combining with c...The transient response of an unlimited cylindrical cavity buried in the infinite elastic soil subjected to an anti-plane impact load along the cavern axis direction was studied.Using Laplace transform combining with contour integral of the Laplace inverse transform specifically,the general analytical expressions of the soil displacement and stress are obtained in the time domain,respectively.And the numerical solutions of the problem computed by analytical expressions are presented.In the time domain,the dynamic responses of the infinite elastic soil are analyzed,and the calculation results are compared with those from numerical inversion proposed by Durbin and the static results.One observes good agreement between analytical and numerical inversion results,lending the further support to the method presented.Finally,some valuable shear wave propagation laws are gained: the displacement of the soil remains zero before the wave arrival,and after the shear wave arrival,the stress and the displacement at this point increase abruptly,then reduce and tend to the static value gradually at last.The wave attenuates along the radial,therefore the farther the wave is from the source,the smaller the stress and the displacement are,and the stress and the displacement are just functions of the radial distance from the axis.展开更多
文摘For a building structure subjected to impulsive loading, particularly shock and impact loading , the response of the critical columns is crucial to the behaviour of the entire system during and after the blast loading phase. Therefore, an appropriate evaluation of the column response and damage under short-duration impulsive loading is important in a comprehensive assessment of the performance of a building system. This paper reports a dynamic analysis approach for the response of RC columns subjected to impulsive loading. Considering that the dynamic response of a column in a frame structure can also be affected by the floor movement which relates to the global vibration of the frame system, a generic column-mass model is used, in which a concentrated mass is attached to the column top to simulate the effect of a global vibration. To take into account the high shear effect under impulsive load, the model is formulated using Timoshenko beam theory, and three main nonlinear mechanisms are considered. Two typical scenarios, one under a direct air blast loading, and another under a blast-induced ground excitation, are analyzed and the primary response features are highlighted.
文摘The transient response of an unlimited cylindrical cavity buried in the infinite elastic soil subjected to an anti-plane impact load along the cavern axis direction was studied.Using Laplace transform combining with contour integral of the Laplace inverse transform specifically,the general analytical expressions of the soil displacement and stress are obtained in the time domain,respectively.And the numerical solutions of the problem computed by analytical expressions are presented.In the time domain,the dynamic responses of the infinite elastic soil are analyzed,and the calculation results are compared with those from numerical inversion proposed by Durbin and the static results.One observes good agreement between analytical and numerical inversion results,lending the further support to the method presented.Finally,some valuable shear wave propagation laws are gained: the displacement of the soil remains zero before the wave arrival,and after the shear wave arrival,the stress and the displacement at this point increase abruptly,then reduce and tend to the static value gradually at last.The wave attenuates along the radial,therefore the farther the wave is from the source,the smaller the stress and the displacement are,and the stress and the displacement are just functions of the radial distance from the axis.
