Nonlinear Analysis of Axisymmetric Layered Pressure Vessels—Part 1: Theory

1989 ◽  
Vol 111 (2) ◽  
pp. 113-119 ◽  
Author(s):  
G. E. Blandford ◽  
T. R. Tauchert ◽  
D. C. Leigh
Keyword(s):  
Heat Conduction ◽  
Time Integration ◽  
Pressure Vessels ◽  
Integration Scheme ◽  
Element Formulation ◽  
Nonlinear Heat Conduction ◽  
Interface Thermal Resistance ◽  
Time Integration Scheme ◽  
Stability And Accuracy ◽  
Stress Dependent

A finite element formulation for the nonlinear heat conduction and thermoelastic analyses of orthotropic, axisymmetric layered pressure vessels is presented. Nonlinearities include temperature-dependent material properties and stress-dependent layer interface conditions. Solution of the nonlinear heat conduction equations is iteratively obtained using a modified Newton-Raphson scheme. Direct iteration between heat conduction and stress analyses is employed when stress-dependent interface thermal resistance is considered. A modified time integration scheme to reduce oscillatory noise is introduced, and the stability and accuracy of the time integration scheme are discussed. Numerical results for various vessel designs and loadings are presented in Part 2 of the paper.

An Efficient Numerical Method for Dynamic Interaction Analysis of High-Speed Shinkansen Vehicles, Rail, and Bridge

1994 ◽  
Author(s):  
Makoto Tanabe ◽  
Hajime Wakui ◽  
Nobuyuki Matsumoto
Keyword(s):  
Finite Element ◽  
Numerical Method ◽  
High Speed ◽  
Interaction Analysis ◽  
Equations Of Motion ◽  
Time Integration ◽  
Integration Scheme ◽  
Element Formulation ◽  
Exact Time ◽  
Time Integration Scheme

Abstract This paper describes a finite element formulation to solve for the combined dynamic behavior of Shinkansen (bullet train) vehicles, irregular rails, and bridges. A mechanical model for interactions between a wheel and an irregular rail is discussed. The bridge is modeled by use of various finite elements. An efficient numerical method, based on modal analysis and exact time integration, is described for solving the nonlinear equations of motion of the Shinkansen vehicle and bridge. The convergence of the exact time integration scheme is discussed and compared with a previous numerical time integration scheme. A finite element computer program has been developed to analyze the dynamic response of Shinkansen vehicles operating at high speed over irregular rails and a bridge. Numerical examples are presented to demonstrate the effectiveness and validity of the present approach.

Alpha-Modification of Cubic B-Spline Direct Time Integration Method

2017 ◽  
Vol 17 (10) ◽  
pp. 1750118 ◽  
Author(s):  
Sobhan Rostami ◽  
Saeed Shojaee
Keyword(s):  
Time Integration ◽  
Degree Of Freedom ◽  
Integration Scheme ◽  
Computational Accuracy ◽  
Structural Dynamic ◽  
B Spline ◽  
Mdof Systems ◽  
Time Integration Scheme ◽  
Simple Step ◽  
Stability And Accuracy

Recently, a conditionally stable explicit time integration scheme using the cubic B-spline function was proposed for solving the structural dynamic problems. This paper presents a new unconditionally stable version of the previous algorithm, based on the uniform cubic B-spline piecewise polynomial approximations and collocation method. First, the method is implemented to solve the differential equation of motion for the single-degree-of-freedom (SDOF) systems. Then, it is generalized for the multi-degree-of-freedom (MDOF) systems. In this paper, a simple step-by-step algorithm is presented for the proposed method, with the stability and accuracy analyses carried out. The unconditional stability of the method is achieved through use of an adjustable collocation parameter [Formula: see text]. The computational accuracy and efficiency of the proposed method are demonstrated in three numerical examples.

scholarly journals 3D mixed virtual element formulation for dynamic elasto-plastic analysis

2021 ◽  
Author(s):  
Mertcan Cihan ◽  
Blaž Hudobivnik ◽  
Fadi Aldakheel ◽  
Peter Wriggers
Keyword(s):  
Time Integration ◽  
Model Performance ◽  
Three Dimensions ◽  
Implicit Time ◽  
Integration Scheme ◽  
Element Formulation ◽  
Elasto Plasticity ◽  
Time Integration Scheme ◽  
Arbitrary Convex ◽  
Virtual Element

AbstractThe virtual element method (VEM) for dynamic analyses of nonlinear elasto-plastic problems undergoing large deformations is outlined within this work. VEM has been applied to various problems in engineering, considering elasto-plasticity, multiphysics, damage, elastodynamics, contact- and fracture mechanics. This work focuses on the extension of VEM formulations towards dynamic elasto-plastic applications. Hereby low-order ansatz functions are employed in three dimensions with elements having arbitrary convex or concave polygonal shapes. The formulations presented in this study are based on minimization of potential function for both the static as well as the dynamic behavior. Additionally, to overcome the volumetric locking phenomena due to elastic and plastic incompressibility conditions, a mixed formulation based on a Hu-Washizu functional is adopted. For the implicit time integration scheme, Newmark method is used. To show the model performance, various numerical examples in 3D are presented.

scholarly journals Structural Reliability Sensitivities under Nonstationary Random Vibrations

2013 ◽  
Vol 2013 ◽  
pp. 1-21 ◽  
Author(s):  
Rita Greco ◽  
Francesco Trentadue
Keyword(s):  
Structural Reliability ◽  
Structural Parameters ◽  
Time Integration ◽  
Structural Response ◽  
Integration Scheme ◽  
Structural Systems ◽  
Frame Building ◽  
Time Integration Scheme ◽  
Noise Input ◽  
The Time Domain

Response sensitivity evaluation is an important element in reliability evaluation and design optimization of structural systems. It has been widely studied under static and dynamic forcing conditions with deterministic input data. In this paper, structural response and reliability sensitivities are determined by means of the time domain covariance analysis in both classically and nonclassically damped linear structural systems. A time integration scheme is proposed for covariance sensitivity. A modulated, filtered, white noise input process is adopted to model the stochastic nonstationary loads. The method allows for the evaluation of sensitivity statistics of different quantities of dynamic response with respect to structural parameters. Finally, numerical examples are presented regarding a multistorey shear frame building.

scholarly journals A new energy–momentum time integration scheme for non-linear thermo-mechanics

2020 ◽  
Vol 372 ◽  
pp. 113395 ◽  
Author(s):  
R. Ortigosa ◽  
A.J. Gil ◽  
J. Martínez-Frutos ◽  
M. Franke ◽  
J. Bonet
Keyword(s):  
Time Integration ◽  
Integration Scheme ◽  
Non Linear ◽  
New Energy ◽  
Time Integration Scheme

New insights into the β1/β2-Bathe time integration scheme when L-stable

2021 ◽  
Vol 245 ◽  
pp. 106433
Author(s):  
Mohammad Mahdi Malakiyeh ◽  
Saeed Shojaee ◽  
Saleh Hamzehei-Javaran ◽  
Klaus-Jürgen Bathe
Keyword(s):  
Time Integration ◽  
Integration Scheme ◽  
Time Integration Scheme
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