scholarly journals Static and Dynamic Characteristics of Composite Conoidal Shell Roofs

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Kaustav Bakshi ◽  
Dipankar Chakravorty
Keyword(s):  
Boundary Conditions ◽  
Forced Vibration ◽  
Integration Method ◽  
Time Integration ◽  
Laminated Composite ◽  
Time Integration Method ◽  
First Approximation ◽  
Curved Elements ◽  
Doubly Curved ◽  
Good Agreement

A thorough review of the existing literature reflects that forced vibration studies of laminated composite conoidal shells with complicated boundary conditions are missing. Hence, the present paper aims to fill the lacuna. A finite element code utilizing eight-noded doubly curved elements together with modified Sanders’ first approximation theory for thin shells is used to study the forced vibration behavior of moderately thin laminated composite conoidal shells subjected to three different uniformly distributed time-dependent forces. Newmark’s direct time integration method is used to solve the dynamic problem. Results obtained using the present code are compared with the values available in the literature, and a good agreement of the results confirms the accuracy of the proposed code. The transient responses of the laminated shell are studied meticulously for parametric variations like boundary conditions and stacking orders of cross and angle-ply laminates and are compared with bending responses of the shell to conclude on the necessity of the dynamic study.

Research on Nonlinear Numerical Simulation Method of Icing Conductor on Galloping

2013 ◽  
Vol 706-708 ◽  
pp. 1799-1804
Author(s):  
Xue Ping Zhan ◽  
Kuan Jun Zhu ◽  
Bin Liu ◽  
Ya Duo Liu ◽  
Xin Min Li
Keyword(s):  
Numerical Simulation ◽  
Integration Method ◽  
Time Integration ◽  
Simulation Method ◽  
Dynamic Responses ◽  
Time Integration Method ◽  
Simulation Calculation ◽  
Numerical Simulation Methods ◽  
Nonlinear Numerical Simulation ◽  
Good Agreement

In this paper,the models of the conductors are constructed by finite element method with a three-node, isoparametric cable element. Two numerical simulation methods that include the 4th order Runge-Kutta (referred to as R-K) method and improved time integration method on galloping are studied, and the numerical results on galloping are given by using those two methods by programming. The study result shows that dynamic responses simulated on galloping by using 4th order R-K method and improved time integration method are in good agreement in this paper, but the efficiency of improved time integration method is higher. Result of this paper can provide beneficial reference for galloping simulation calculation.

scholarly journals An Improved Time Integration Method Based on Galerkin Weak Form with Controllable Numerical Dissipation

2021 ◽  
Vol 11 (4) ◽  
pp. 1932
Author(s):  
Weixuan Wang ◽  
Qinyan Xing ◽  
Qinghao Yang
Keyword(s):  
High Frequency ◽  
Integration Method ◽  
Time Integration ◽  
Low Frequency ◽  
Weak Form ◽  
High Accuracy ◽  
Numerical Dissipation ◽  
Frequency Range ◽  
Time Integration Method ◽  
Numerical Damping

Based on the newly proposed generalized Galerkin weak form (GGW) method, a two-step time integration method with controllable numerical dissipation is presented. In the first sub-step, the GGW method is used, and in the second sub-step, a new parameter is introduced by using the idea of a trapezoidal integral. According to the numerical analysis, it can be concluded that this method is unconditionally stable and its numerical damping is controllable with the change in introduced parameters. Compared with the GGW method, this two-step scheme avoids the fast numerical dissipation in a low-frequency range. To highlight the performance of the proposed method, some numerical problems are presented and illustrated which show that this method possesses superior accuracy, stability and efficiency compared with conventional trapezoidal rule, the Wilson method, and the Bathe method. High accuracy in a low-frequency range and controllable numerical dissipation in a high-frequency range are both the merits of the method.

scholarly journals Impact of difference between explicit and implicit second-order time integration schemes on isotropic/anisotropic steady incompressible turbulence field

2021 ◽  
Vol 2090 (1) ◽  
pp. 012145
Author(s):  
Ryuma Honda ◽  
Hiroki Suzuki ◽  
Shinsuke Mochizuki
Keyword(s):  
Kinetic Energy ◽  
Energy Conservation ◽  
Integration Method ◽  
Time Integration ◽  
Second Order ◽  
Implicit Time ◽  
Explicit Time Integration ◽  
Time Integration Method ◽  
Implicit Time Integration ◽  
Time Integration Methods

Abstract This study presents the impact of the difference between the implicit and explicit time integration methods on a steady turbulent flow field. In contrast to the explicit time integration method, the implicit time integration method may produce significant kinetic energy conservation error because the widely used spatial difference method for discretizing the governing equations is explicit with respect to time. In this study, the second-order Crank-Nicolson method is used as the implicit time integration method, and the fourth-order Runge-Kutta, second-order Runge-Kutta and second-order Adams-Bashforth methods are used as explicit time integration methods. In the present study, both isotropic and anisotropic steady turbulent fields are analyzed with two values of the Reynolds number. The turbulent kinetic energy in the steady turbulent field is hardly affected by the kinetic energy conservation error. The rms values of static pressure fluctuation are significantly sensitive to the kinetic energy conservation error. These results are examined by varying the time increment value. These results are also discussed by visualizing the large scale turbulent vortex structure.

Time integration method to determine the characteristic parameter of a light extinctiometer

1993 ◽  
Vol 15 (1) ◽  
pp. 42-48 ◽  
Author(s):  
J. H. Geng ◽  
A. van de Ven ◽  
F. Zhang ◽  
H. Grönig
Keyword(s):  
Integration Method ◽  
Time Integration ◽  
Characteristic Parameter ◽  
Time Integration Method
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