scholarly journals Theoretical and Experimental Study of the Pounding Response for Adjacent Inelastic MDOF Structures Based on Dimensional Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Qiaoyun Wu ◽  
Ziliang Liu ◽  
Tao Wang ◽  
Xuyong Chen
Keyword(s):  
Dimensional Analysis ◽  
Impact Force ◽  
Theoretical Method ◽  
Shaking Table ◽  
Earthquake Excitation ◽  
Kelvin Model ◽  
Matlab Program ◽  
Steel Frame Structures ◽  
Collision Processes ◽  
The Impact

Dimensional analysis is applied to study the pounding response of two inelastic multidegree of freedom (MDOF) structures under simplified earthquake excitation. The forces and deformations of the collision processes are simulated by adopting the improved Kelvin pounding model. The inelastic characteristics of MDOF structures are described by the bilinear interstory resistance model, and the representations of dimensionless impact force and the dimensionless motion equation in the pounding process are derived. On the basis of the above-mentioned theoretical deduction, the superiority of the improved Kelvin model is verified by comparing the impact response of the improved Kelvin model and the Kelvin model. Finally, the validity of the proposed theoretical method is further proved by the comparison between results from the shaking table tests of adjacent four-story and three-story steel frame structures and the corresponding numerical results obtained by the MATLAB program.

scholarly journals Theoretical Analysis of Rockfall Impacts on the Soil Cushion Layer of Protective Structures

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Xing Wang ◽  
Yongxu Xia ◽  
Tianyue Zhou
Keyword(s):  
Numerical Simulation ◽  
Energy Conservation ◽  
Penetration Depth ◽  
Impact Force ◽  
Theoretical Method ◽  
Cavity Expansion ◽  
Rockfall Hazards ◽  
Protective Structures ◽  
Cushion Layer ◽  
The Impact

During the Wenchuan Earthquake, with a magnitude of 5.12, collapses and rockfall hazards persisted for a long time after the initial investigations carried out by research fellow S. M. He and his team at the scene of the disaster in October 2008. It is possible that additional incidents of rockfalls in large quantities may continue in the same areas over the next ten to fifteen years. Furthermore, in the vast mountainous region of western China, the topographic relief is evident, and earthquakes occur frequently. Therefore, it is difficult to effectively defend against rockfall hazards. When designing protective structures, the key issue is the analysis of the mechanical response mechanism of the soil cushion layer of the upper cushion when subjected to the impact of rockfall. As such, a theoretical method was used to perform such an analysis. The cavity expansion and energy conservation model were adopted. Analytical solutions for the impact force and penetration depth were then derived. Furthermore, the impact force and penetration depth of rockfall were studied with the LS-DYNA software to obtain values for the impact forces and the penetration depth. Finally, the reliability of the theoretical method was evaluated using the cavity expansion, energy conservation, numerical simulation, Hertz, Japanese, Swiss, Australian, B. S. Guan, tunnel manual, and subgrade methods based on an engineering model. The results show that the cavity expansion and the energy conservation methods yielded consistent results. Meanwhile, the cavity expansion and the energy conservation methods also yielded consistent results with the numerical simulation, Japanese (obtained by laboratory experiment), Swiss (obtained by laboratory experiment), and Australian (obtained by field experiment) methods. The relevant methods and conclusions shall therefore be applied to the design of rockfall protection structure in future investigations.

Shaking Table Test on Seismic Pounding Response of Reinforced Concrete Bridge

2013 ◽  
Vol 671-674 ◽  
pp. 1519-1523
Author(s):  
Xiao Yu Yan ◽  
Li Hui Wang ◽  
Xiu Li Du
Keyword(s):  
Reinforced Concrete ◽  
Shaking Table Test ◽  
Impact Force ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Reinforced Concrete Bridge ◽  
Rigid Frame ◽  
Seismic Pounding ◽  
Rigid Frame Bridge ◽  
The Impact

To investigate the response of the bridge pounding, shaking table test was performed using 1/10 scaled reinforced concrete rigid frame bridge specimen. The influence of traveling effect on pounding and the anti-impact capability using dampers were discussed. The experimental results demonstrate that the acceleration responses of the girder and bridge piers, the frequency and the impact force are increased when the traveling wave excitation is considered. Moreover, relatively displacement of the adjacent bridge frames increased magnitudely. Dynamic responses, the frequency and the impact force are decrease when the dampers are installed.Therefore, installation of the dampers is a sustainable and effective way to improve the anti-impact capability.

scholarly journals Study on Pounding Response of Adjacent Inelastic SDOF Structures Based on Dimensional Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Xuyong Chen ◽  
Huipeng Guo ◽  
Tao Wang ◽  
Qiaoyun Wu
Keyword(s):  
Dimensional Analysis ◽  
Frequency Ratio ◽  
Structural Parameters ◽  
Contact Process ◽  
Structural Response ◽  
Mass Ratio ◽  
Earthquake Excitation ◽  
Kelvin Model ◽  
Dimensionless Equation ◽  
Adjacent Structures

The dimensional analysis method is applied to study the pounding response of two inelastic single-degree-of-freedom (SDOF) structures under simplified earthquake excitation. The improved Kelvin pounding model is used to simulate the force and deformation of the collider during the contact process. Using bilinear interstory resistance model to simulate the inelastic characteristics of SDOF structures, the expression of dimensionless pounding force and the dimensionless equation of motion during the pounding process are deduced. When dimensionless parameters are used to represent the colliding equation of adjacent inelastic SDOF structures, the variables affecting the pounding response of the adjacent structures are reduced from 14 to 11, which can clearly reflect the rules during the pounding process. The correctness and superiority of the improved Kelvin model are verified by comparing the pounding responses between the improved Kelvin model and Kelvin model. The pounding response of the two inelastic SDOF structures with improved Kelvin model is illustrated in the form of spectra, and the self-similarity of pounding response of the two inelastic SDOF structures is revealed. The effects of structural parameters on the pounding response are analyzed. The results show that the effects of mass ratio, frequency ratio, and initial spacing between the adjacent inelastic SDOF structures on the pounding response of the left-side structure (with smaller mass and stiffness) are closely related to the division of spectral regions. For the right-side structure with larger mass and stiffness, the amplification of pounding on structural response increases with the increase of mass ratio Π m and decreases with the increase of frequency ratio μ and structural spacing Π d .

scholarly journals Numerical Study on Pounding between Two Adjacent Buildings under Earthquake Excitation

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
H. Naderpour ◽  
R. C. Barros ◽  
S. M. Khatami ◽  
R. Jankowski
Keyword(s):  
Impact Force ◽  
Viscoelastic Model ◽  
Coefficient Of Restitution ◽  
Earthquake Excitation ◽  
Structural Pounding ◽  
Adjacent Buildings ◽  
Impact Forces ◽  
Nonlinear Viscoelastic ◽  
Nonlinear Viscoelastic Model ◽  
The Impact

Seismic excitation, which results in large horizontal relative displacements, may cause collisions between two adjacent structures due to insufficient separation distance between them. Such collisions, known as earthquake-induced structural pounding, may induce severe damage. In this paper, the case of pounding between two adjacent buildings is studied by the application of single degree-of-freedom structural models. Impact is numerically simulated with the use of a nonlinear viscoelastic model. Special attention is focused on calculating values of impact forces during collisions which have significant influence of pounding-involved response under ground motions. The results of the study indicate that the impact force time history is much dependent on the earthquake excitation analyzed. Moreover, the peak impact forces during collision depend substantially on such parameters as gap size, coefficient of restitution, impact velocity, and stiffness of impact spring element. The nonlinear viscoelastic model of impact force with the considered relation between the damping coefficient and the coefficient of restitution has also been found to be effective in simulating earthquake-induced structural pounding.

FORMULATION ON THE EMPIRICAL EQUATION OF THE CASK IMPACT FORCES BY DIMENSIONAL ANALYSIS

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1612-1617 ◽  
Author(s):  
YOUNG-SHIN LEE ◽  
YONG-JAE KIM ◽  
YOUNG-JIN CHOI ◽  
EUN-YUP LEE
Keyword(s):  
Dimensional Analysis ◽  
Empirical Equation ◽  
Impact Force ◽  
The Body ◽  
Radioactive Material ◽  
Spent Fuel ◽  
Element Analysis ◽  
Safety Standards ◽  
Safe Transport ◽  
The Impact

Radioactive material is used in the various fields. The numbers of transport for radioactive material have been gradually increased in both domestic and international regions. The safety of the cask should be secured to safely transport of radioactive material. The Korean atomic law and the IAEA safety standards prescribe regulations for the safe transport of radioactive material. The cask for spent fuel is comprised of the body and the impact limiter. In this study, the empirical equation of the cask impact force was proposed based on the dimensional analysis. Using this empirical equation the characteristics of the impact limiter were analyzed. The results are also validated by comparing with the previous results of the impact area method and the finite element analysis. The present method can be used to predict the impact force of the cask.

Some thought on the Estimating of the Impact Force by an Experiment

2019 ◽  
Vol 7 (2) ◽  
pp. 205-213
Author(s):  
Yong-Doo Kim ◽  
Seung-Jae Lim ◽  
Hyun-Ung Bae ◽  
Kyoung-Ju Kim ◽  
Chin-Ok Lee ◽  
...  
Keyword(s):  
Impact Force ◽  
The Impact

scholarly journals Sandwich panel with in-plane honeycombs in different Poisson's ratio under low to medium impact loads

2021 ◽  
Vol 60 (1) ◽  
pp. 145-157
Author(s):  
Yi Luo ◽  
Ke Yuan ◽  
Lumin Shen ◽  
Jiefu Liu
Keyword(s):  
Poisson’S Ratio ◽  
Sandwich Panel ◽  
Impact Force ◽  
Impact Resistance ◽  
Poisson's Ratio ◽  
Compression Performance ◽  
Post Impact ◽  
Local Impact ◽  
Collapse Behavior ◽  
The Impact

Abstract In this study, a series of in-plane hexagonal honeycombs with different Poisson's ratio induced by topological diversity are studied, considering re-entrant, semi-re-entrant and convex cells, respectively. The crushing strength of honeycomb in terms of Poisson's ratio is firstly presented. In the previous research, we have studied the compression performance of honeycomb with different negative Poisson's ratio. In this study, a comparative study on the local impact resistance of different sandwich panels is conducted by considering a spherical projectile with low to medium impact speed. Some critical criteria (i.e. local indentation profile, global deflection, impact force and energy absorption) are adopted to analyze the impact resistance. Finally, an influential mechanism of Poisson's ratio on the local impact resistance of sandwich panel is studied by considering the variation of core strength and post-impact collapse behavior.

Pre-Impact Configuration Designing of a Robot Manipulator for Impact Minimization

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Jingchen Hu ◽  
Tianshu Wang
Keyword(s):  
Impact Force ◽  
Robot Manipulator ◽  
Analytical Formula ◽  
Joint Space ◽  
Collision Problem ◽  
Spatial Operator ◽  
Inertia Ellipsoid ◽  
The Impact ◽  
Maximum Minimum ◽  
Simple Analytical Formula

This paper studies the collision problem of a robot manipulator and presents a method to minimize the impact force by pre-impact configuration designing. First, a general dynamic model of a robot manipulator capturing a target is established by spatial operator algebra (SOA) and a simple analytical formula of the impact force is obtained. Compared with former models proposed in literatures, this model has simpler form, wider range of applications, O(n) computation complexity, and the system Jacobian matrix can be provided as a production of the configuration matrix and the joint matrix. Second, this work utilizes the impulse ellipsoid to analyze the influence of the pre-impact configuration and the impact direction on the impact force. To illustrate the inertia message of each body in the joint space, a new concept of inertia quasi-ellipsoid (IQE) is introduced. We find that the impulse ellipsoid is constituted of the inertia ellipsoids of the robot manipulator and the target, while each inertia ellipsoid is composed of a series of inertia quasi-ellipsoids. When all inertia quasi-ellipsoids exhibit maximum (minimum) coupling, the impulse ellipsoid should be the flattest (roundest). Finally, this paper provides the analytical expression of the impulse ellipsoid, and the eigenvalues and eigenvectors are used as measurements to illustrate the size and direction of the impulse ellipsoid. With this measurement, the desired pre-impact configuration and the impact direction with minimum impact force can be easily solved. The validity and efficiency of this method are verified by a PUMA robot and a spatial robot.

Study on Impact Compaction of Aeolian Sand Subgrade and its Effect Evaluation

2011 ◽  
Vol 378-379 ◽  
pp. 370-373
Author(s):  
Yu Qing Yuan ◽  
Xuan Cang Wang ◽  
Hui Jun Shao
Keyword(s):  
Rayleigh Wave ◽  
Impact Force ◽  
Engineering Practice ◽  
Effect Evaluation ◽  
Aeolian Sand ◽  
Field Compaction ◽  
Vibratory Compaction ◽  
Strength And Stiffness ◽  
The Impact ◽  
Elastic Stage

In order to solve the problem of aeolian sand subgrade compaction, we studied the technology of impact compaction, applied it to the engineering practice and analyzed its effect with Rayleigh wave. The technology of impact compaction can combine the compaction of potential energy and kinetic energy and make it easier for the materials to reach their elastic stage. With the combined function of "knead-roll-impact", the impact compaction road roller can compact the soil body and offer 6～10 times impact force and 3～4 times the depth of influence more than the vibratory roller. The impact compaction methods of aeolian sand subgrade were put forward. The comparative field compaction tests between impact and vibratory compaction are carried through, which are detected by Rayleigh wave. The results show that the impact compaction can make the density of the aeolian sand subgrade 2～5% higher than the vibratory compaction, and reach the influence depth of 7 metres. To sum up, the impact compaction can clearly increases the strength and stiffness of aeolian sand subgrade with a dynamic elastic modulus of 202.63MPa.

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