scholarly journals Nonlinear Dynamic Analysis of Macrofiber Composites Laminated Shells

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Xiangying Guo ◽  
Dameng Liu ◽  
Wei Zhang ◽  
Lin Sun ◽  
Shuping Chen
Keyword(s):  
Differential Equations ◽  
Nonlinear Dynamic ◽  
Dynamic Models ◽  
Three Dimensional ◽  
Nonlinear Dynamic Analysis ◽  
Dynamical Analysis ◽  
Phase Portraits ◽  
Chaotic Motions ◽  
Laminated Shells ◽  
Laminated Shell

This work presents the nonlinear dynamical analysis of a multilayer d31 piezoelectric macrofiber composite (MFC) laminated shell. The effects of transverse excitations and piezoelectric properties on the dynamic stability of the structure are studied. Firstly, the nonlinear dynamic models of the MFC laminated shell are established. Based on known selected geometrical and material properties of its constituents, the electric field of MFC is presented. The vibration mode-shape functions are obtained according to the boundary conditions, and then the Galerkin method is employed to transform partial differential equations into two nonlinear ordinary differential equations. Next, the effects of the transverse excitations on the nonlinear vibration of MFC laminated shells are analyzed in numerical simulation and moderating effects of piezoelectric coefficients on the stability of the system are also presented here. Bifurcation diagram, two-dimensional and three-dimensional phase portraits, waveforms phases, and Poincare diagrams are shown to find different kinds of periodic and chaotic motions of MFC shells. The results indicate that piezoelectric parameters have strong effects on the vibration control of the MFC laminated shell.

Nonlinear Dynamics and Application of the Four Dimensional Autonomous Hyper-Chaotic System

2014 ◽  
Author(s):  
Ge Kai ◽  
Wei Zhang
Keyword(s):  
Nonlinear Dynamics ◽  
Numerical Simulation ◽  
Differential Equations ◽  
Chaotic System ◽  
Dynamical Behavior ◽  
Three Dimensional ◽  
Phase Portraits ◽  
State Variables ◽  
Chaotic Motions ◽  
Finance System

In this paper, we establish a dynamic model of the hyper-chaotic finance system which is composed of four sub-blocks: production, money, stock and labor force. We use four first-order differential equations to describe the time variations of four state variables which are the interest rate, the investment demand, the price exponent and the average profit margin. The hyper-chaotic finance system has simplified the system of four dimensional autonomous differential equations. According to four dimensional differential equations, numerical simulations are carried out to find the nonlinear dynamics characteristic of the system. From numerical simulation, we obtain the three dimensional phase portraits that show the nonlinear response of the hyper-chaotic finance system. From the results of numerical simulation, it is found that there exist periodic motions and chaotic motions under specific conditions. In addition, it is observed that the parameter of the saving has significant influence on the nonlinear dynamical behavior of the four dimensional autonomous hyper-chaotic system.

Three-dimensional nonlinear response history analyses for earthquake damage assessment: A reinforced concrete wall building case study

2020 ◽  
pp. 875529302094418
Author(s):  
Jorge A Vásquez ◽  
Rosita Jünemann ◽  
Juan C de la Llera ◽  
Matías A Hube ◽  
Matías F Chacón
Keyword(s):  
Reinforced Concrete ◽  
Nonlinear Dynamic ◽  
Structural Damage ◽  
Dynamic Models ◽  
Residential Buildings ◽  
Three Dimensional ◽  
Nonlinear Dynamic Analysis ◽  
Shear Wall ◽  
Concrete Wall ◽  
Building Collapse

Nonlinear dynamic analysis techniques have made significant progress in the last 20 years, providing powerful tools for assessing structural damage and potential building collapse mechanisms. The fact that several reinforced concrete shear wall residential buildings underwent severe structural damage in walls at the lower building levels during the 2010 Maule earthquake (Chile) presents a scientific opportunity to assess the predictive quality of these techniques. The objective of this research is to compare building responses using two completely different three-dimensional nonlinear dynamic models and study in detail the observed damage pattern and wall collapse of one reinforced concrete shear wall building in Santiago, Chile. The first model is a mixed fiber-shell model developed in MATLAB, and the second is a shell finite element model developed in the software DIANA. Results of both models are consistent with the hypothesis that high axial loads trigger a limited ductility failure in critical walls at roof-to-base drift ratios less than 0.34% with little capacity of hysteretic energy dissipation, which contradicts the ductile design philosophy of current code provisions.

scholarly journals Nonlinear Dynamic Analysis and Chaos Prediction of Grinding Motorized Spindle System

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Weitao Jia ◽  
Feng Gao ◽  
Yan Li ◽  
Wenwu Wu ◽  
Zhongwei Li
Keyword(s):  
Nonlinear Dynamic ◽  
High Speed ◽  
Chaotic Behavior ◽  
Nonlinear Dynamic Analysis ◽  
Phase Portraits ◽  
Impact Factors ◽  
Nonlinear Dynamic Model ◽  
Motorized Spindle ◽  
Spindle System ◽  
The Impact

The paper determines the impact factors of dynamics of a motorized spindle rotor system due to high speed: centrifugal force and bearing stiffness softening. A nonlinear dynamic model of the grinding motorized spindle system considering the above impact factors is constructed. Through system simulation including phase portraits and Poincaré map, the periodic behavior and chaotic behavior of the nonlinear grinding motorized spindle system are revealed. The threshold curve of chaos motion is obtained through the Melnikov method. The conclusion can provide a theoretical basis for researching deeply the dynamic behaviors of the grinding motorized spindle system.

scholarly journals Influence of Piezoelectric Performance on Nonlinear Dynamic Characteristics of MFC Shells

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xiangying Guo ◽  
Pan Jiang ◽  
Dongxing Cao
Keyword(s):  
Electric Field ◽  
Nonlinear Dynamic ◽  
Piezoelectric Properties ◽  
Great Influence ◽  
Dynamic Responses ◽  
Aerodynamic Forces ◽  
External Excitation ◽  
Structural Dynamic ◽  
Laminated Shells ◽  
Laminated Shell

Based on the structures of unmanned aerial vehicle (UAV) wings, nonlinear dynamic analysis of macrofiber composite (MFC) laminated shells is presented in this paper. The effects of piezoelectric properties and aerodynamic forces on the dynamic stability of the MFC laminated shell are studied. Firstly, under the flow condition of ideal incompressible fluid, the thin airfoil theory is employed to calculate the effects of the mean camber line to obtain the circulation distribution of the wings in subsonic air flow. The steady aerodynamic lift on UAV wings is derived by using the Kutta–Joukowski lift theory. Then, considering the geometric nonlinearity and piezoelectric properties of the MFC material, the nonlinear dynamic model of the MFC laminated shell is established with Hamilton’s principles and the Galerkin method. Next, the effects of electric field, external excitation force, and nonlinear parameters on the stability of the system are studied under 1 : 1 internal resonance and the effects of material parameters on the natural frequency of the structure are also analyzed. Furthermore, the influence of the aerodynamic forces and electric field on the nonlinear dynamic responses of MFC laminated shells is discussed by numerical simulation. The results indicate that the electric field and external excitation have great influence on the structural dynamic responses.

Ground motion sensitivity of a Vancouver-style high rise

2004 ◽  
Vol 31 (2) ◽  
pp. 292-307 ◽  
Author(s):  
Timothy White ◽  
Carlos E Ventura
Keyword(s):  
Reinforced Concrete ◽  
Ground Motion ◽  
Nonlinear Dynamic ◽  
Dynamic Properties ◽  
Three Dimensional ◽  
Nonlinear Dynamic Analysis ◽  
Ground Shaking ◽  
Motion Sensitivity ◽  
High Rise ◽  
Ground Motion Records

The purpose of the study discussed in this paper is to evaluate the seismic response of a modern building, designed according to the current building code and to extreme earthquake earthquakes from two different source mechanisms. To this end, a three-dimensional nonlinear dynamic response of a reinforced concrete high-rise building, typical of the type built in Vancouver, British Columbia, is investigated. According to current design practice, the building has been designed to resist lateral loads with a coupled shearwall system. A comparison of the responses of the building to crustal and subduction type earthquakes of similar magnitudes is presented and discussed. The ground motion records selected for this study were derived from recorded crustal and subduction events, which are both considered to be extreme, and beyond the code-based design requirements of the building. A part of this study includes an evaluation of how the dynamic properties of the building change as the building is being damaged by severe ground shaking. The results of the study show that the crustal earthquake imposes large upper levels displacements, and much plastic hinging near the base because the response of the building is governed mainly by the first mode of the "undamaged" system. The subduction earthquake results in displacements smaller than those from the crustal event and causes plastic hinging at mid-height and near the base as well as large torsional rotations, because the behaviour of the building is greatly influenced by the second mode of the "damaged" system.Key words: nonlinear dynamic analysis, seismic, high rise, reinforced concrete, coupled shearwall.

Dynamics of Slightly Curved Pipe Conveying Hot Pressurized Fluid Resting on Linear and Nonlinear Viscoelastic Foundations

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
O. D. Owoseni ◽  
K. O. Orolu ◽  
A. A. Oyediran
Keyword(s):  
Differential Equations ◽  
Oil And Gas ◽  
Chaotic Oscillation ◽  
Oil And Gas Industry ◽  
Phase Portraits ◽  
Chaotic Motions ◽  
Gas Industry ◽  
Curved Pipe ◽  
Nonlinear Viscoelastic ◽  
Seventh Order

One of the most important facilities in the oil and gas industry is the pipeline. These pipelines convey high pressure with high temperature (HPHT) fluids and transit several kilometers traveling through different seafloor soils. The topography of seabed which acts as viscoelastic foundation to the pipeline is rough and irregular, thereby making the pipelines to be slightly curved. This erratic behavior of these soils presents several problems to the constructor and threatens the lifespan of the pipeline. The nonlinear governing partial differential equations (PDEs) were derived and solved using energy and eigenfunction expansion methods, respectively. The resultant ordinary differential equations (ODEs) were truncated after the fourth mode and solved numerically using eighth-seventh order Runge–Kutta code in matlab. Two types of foundations were investigated: both with viscous damping but one was with linear spring, while the other was with nonlinear spring. Bifurcation and orbit diagrams with their corresponding phase portraits that show periodic and chaotic motions of the system trajectories are generated and presented. It was examined that foundation, initial curvature, and tension could stiffen the pipe, while pressure and temperature did the rule of softening. Nonlinear stiffness made the pipe to undergo chaotic oscillation which was absent in the linear case, meaning that linear foundations could enhance the life span of pipelines than the nonlinear ones.

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