scholarly journals Rocking Response Analysis of Self-Centering Walls under Ground Excitations

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xiaobin Hu ◽  
Qinwang Lu ◽  
Yang Yang
Keyword(s):  
Dynamic Response ◽  
Equations Of Motion ◽  
Numerical Procedure ◽  
Elastic Stiffness ◽  
The Self ◽  
Response Analysis ◽  
Seismic Excitations ◽  
Parametric Studies ◽  
Initial Force ◽  
Rocking Response

This paper presents a numerical procedure to simulate the rocking response of self-centering walls under ground excitations. To this aim, the equations of motion that govern the dynamic response of self-centering walls are first formulated and then solved numerically, in which three different self-centering wall structural systems are considered, that is, (i) including the self-weight of the wall only, (ii) including posttensioned tendon, and (iii) including both posttensioned tendon and dampers. Following the development of the numerical procedure, parametric studies are then carried out to investigate the influence of a variety of factors on the dynamic response of the self-centering wall under seismic excitations. The investigation results show that within the cases studied in this paper the installation of posttensioned tendon is capable of significantly enhancing the self-centering ability of the self-centering wall. In addition, increasing either the initial force or the elastic stiffness of the posttensioned tendon can reduce the dynamic response of the self-centering wall in terms of the rotation angle and angular velocity, whereas the former approach is found to be more effective than the latter one. It is also revealed that the addition of the dampers is able to improve the energy dissipation capacity of the self-centering wall. Furthermore, for the cases studied in this paper the yield strength of the dampers appears to have a more significant effect on the dynamic response of the self-centering wall than the elastic stiffness of the dampers.

scholarly journals A Simplified Model for Dynamic Response Analysis of Framed Self-Centering Wall Structures under Seismic Excitations

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Xiaobin Hu ◽  
Chen Lu ◽  
Xiaoqing Zhu
Keyword(s):  
Dynamic Response ◽  
Elastic Stiffness ◽  
Simplified Model ◽  
Design Parameters ◽  
Response Analysis ◽  
Seismic Responses ◽  
Analysis Model ◽  
Seismic Excitations ◽  
Element Analysis ◽  
Dynamic Response Analysis

This paper presents a simplified model for dynamic response analysis of the framed self-centering wall (FSCW) structure under seismic excitations. In the analysis model, the frame is equivalent as a single-degree-of-freedom system and collaborates with the self-centering (SC) wall to resist lateral loads. By way of pushover analysis of a typical FSCW structure, the proposed analysis model is validated by comparing the analysis results with those obtained from the finite element analysis method. Using the analysis model, motion equations of the FSCW structure under seismic excitations are established and solved through numerical simulations. Finally, a comprehensive parametric study is conducted to investigate the effects of a variety of design parameters on seismic responses of the FSCW structure. It shows that improving the yield force or elastic stiffness of the frame can help greatly lessen seismic responses of the FSCW structure in terms of the rotation angle of the SC wall.

Nonlinear Dynamics Analysis of a Laminated Printed Wiring Board

2002 ◽  
Vol 124 (2) ◽  
pp. 77-84 ◽  
Author(s):  
Xiaoling He ◽  
Robert E. Fulton
Keyword(s):  
Dynamic Response ◽  
Large Deflection ◽  
Equations Of Motion ◽  
Response Analysis ◽  
Printed Wiring Board ◽  
High Acceleration ◽  
Dynamic Stress Field ◽  
Laminate Theory ◽  
Wiring Board ◽  
Nonlinear Elastic

Nonlinear laminate theory is applied for the printed wiring board (PWB) dynamic response analysis. Equations of motion for the nonlinear elastic deformation of the isotropic laminates are derived for the dynamic response of a simply supported PWB. Numerical results are generated for the nonlinear response characterization of the PWB deformation. Comparisons are made between the response of linear and nonlinear systems. Results show that PWB is in large deflection under high acceleration or certain pressure load. Nonlinear theory gives more accurate results for the large deflection than the linear theory does. Besides, lamina stresses are analyzed and illustrated from finite difference computation. The analytical derivation in modal approach and the stress analysis provide the basis for PWB reliability studies, especially the defect and failure induced by the dynamic stress field.

Dynamic Response Analysis of Large Latticed Space Structures

1989 ◽  
Vol 4 (1) ◽  
pp. 25-42 ◽  
Author(s):  
A.R. Kukreti ◽  
N.D. Uchil
Keyword(s):  
Dynamic Response ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Computational Time ◽  
Space Structures ◽  
Response Analysis ◽  
Actual System ◽  
Large Space ◽  
Element Analysis ◽  
Dynamic Response Analysis

In this paper an alternative method for dynamic response analysis of large space structures is presented, for which conventional finite element analysis would require excessive computer storage and computational time. Latticed structures in which the height is very small in comparison to its overall length and width are considered. The method is based on the assumption that the structure can be embedded in its continuum, in which any fiber can translate and rotate without deforming. An appropriate kinematically admissable series function is constructed to descrbe the deformation of the middle plane of this continuum. The unknown coefficients in this function are called the degree-of-freedom of the continuum, which is given the name “super element.” Transformation matrices are developed to express the equations of motion of the actual systems in terms of the degrees-of-freedom of the super element. Thus, by changing the number of terms in the assumed function, the degrees-of-freedom of the super element can be increased or decreased. The super element response results are transformed back to obtain the desired response results of the actual system. The method is demonstrated for a structure woven in the shape of an Archimedian spiral.

Dynamic Response Analysis and Comparative Study of Circular Cylindrical Shell Subjected to Radial Impact

2007 ◽  
Vol 51 (02) ◽  
pp. 94-103
Author(s):  
Li Xuebin
Keyword(s):  
Cylindrical Shell ◽  
Dynamic Response ◽  
Normal Mode ◽  
Shell Theory ◽  
Circular Cylindrical Shell ◽  
Equations Of Motion ◽  
Response Analysis ◽  
Mode Theory ◽  
Normal Mode Theory ◽  
Exact Derivation

Following Flu¨ gge's exact derivation for the buckling of cylindrical shells, the equations of motion for dynamic loading of a circular cylindrical shell under external hydrostatic pressure have been formulated. The normal mode theory is used to provide transient dynamic response for the equations of motion. The responses of displacements, strain, and stress are obtained for the area of impact, while those outside the area of impact are also calculated. The accuracy of normal mode theory and Timoshenko shell theory are examined in this paper.

Improved Large Spring / Stiffness Technique for Dynamic Response Analysis of Structures Subjected to Base Excitations

2011 ◽  
Vol 474-476 ◽  
pp. 1974-1979
Author(s):  
Guo Liang Zhou ◽  
Xiao Jun Li ◽  
Xiao Bo Peng
Keyword(s):  
Dynamic Response ◽  
Dynamic Analysis ◽  
Response Analysis ◽  
Spring Stiffness ◽  
Seismic Excitations ◽  
Structural Dynamic ◽  
Theoretical Methods ◽  
Rayleigh Damping ◽  
Stiffness Method ◽  
Improved Technique

Based on the large spring/stiffness method (LSM), this paper develops an improved technique (I-LSM) applicable to structural dynamic analysis with the assumption of Rayleigh damping. To estimate the accuracy of the technique, the dynamic response is analyzed for a 2-DOFs model respectively subjected to uniform/nonuniform seismic excitations. It indicates that the traditional LSM is inapplicable when Rayleigh damping is adopted. And the errors increase monotonously with the aggrandizement of damping. It’s also validated that the I-LSM based on the modification of displacement considering the influences of Rayleigh damping presented in this paper is able to effectively yield results almost identical to those of theoretical methods with errors beneath 4%.

scholarly journals Dynamic Response Analysis of a Thin Plate with Partially Constrained Layer Damping Optimization under Moving Loads for Various Boundary Conditions

2021 ◽  
Vol 11 (7) ◽  
pp. 3282
Author(s):  
Yun Qin ◽  
Qinghua Song ◽  
Zhanqiang Liu ◽  
Jiahao Shi
Keyword(s):  
Dynamic Response ◽  
Loss Factor ◽  
Lagrange Equation ◽  
Differential Quadrature Method ◽  
Equations Of Motion ◽  
Shear Deformation Theory ◽  
Response Analysis ◽  
Constrained Layer Damping ◽  
Moving Loads ◽  
Damping Loss Factor

In this paper, the vibration analysis of a partially constrained layer damping plate subjected to moving loads is investigated. In addition, the first four order damping loss factor of the system is optimized with the location of partially constrained layer damping as a design variable. The equations of motion of a partially constrained layer damping plate are derived through the Lagrange equation based on first order shear deformation theory (FSDT). Next, using an extended Rayleigh–Ritz solution together with the penalty method expresses the unknown displacement terms, and the differential quadrature method is proposed to obtain the dynamic response of the system in the time domain. A multi-population genetic algorithm (MPGA) is employed to deal with the optimization of the damping loss factor of a partially constrained layer damping plate. To ensure the accuracy of the method presented in this study, the numerical results are comprehensively verified by experiments and open literature. The optimization results show that the damping loss factor increases when the position of the patch is close to the constraint boundary, and the best strategy is to optimize the low order damping loss factor of the system under moving loads. It is believed that the research results are of interest to engineering science.

Dynamic Response and Reliability of Six-Leg Jack-Up Type Wind Turbine Installation Vessel

2017 ◽  
Vol 17 (03) ◽  
pp. 1750037 ◽  
Author(s):  
Sanghwan Heo ◽  
Weoncheol Koo ◽  
Min-Su Park
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Time Integration ◽  
Numerical Procedure ◽  
Slender Body ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Natural Period ◽  
Jack Up ◽  
Turbine Installation

A fast, reliable and optimized numerical procedure of the hydrodynamic response analysis of a slender-body structure is presented. With this method, the dynamic response and reliability of a six-leg jack-up-type wind turbine installation vessel under various environmental conditions is analyzed. The modified Morison equation is used to calculate the wave and wind-driven current excitation forces on the slender-body members. The Det Norske Veritas (DNV) rule-based formula is used to calculate the wind loads acting on the superstructure of the jack-up leg. From the modal analysis, the natural period and standardized displacement of the structure are determined. The Newmark-beta time-integration method is used to solve the equation of motion generating the time-varying dynamic responses of the structure. A parametric study is carried out for various current velocities and wind speeds. In addition, a reliability analysis is conducted to predict the effects of uncertainty of the wave period and wave height on the safety of structural design, using the reliability index to indicate the reliability of the dynamic response on the critical structural members.

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