scholarly journals Dynamic Research of a Nonlinear Stochastic Vibratory Machine

2002 ◽  
Vol 9 (6) ◽  
pp. 277-281 ◽  
Author(s):  
Yimin Zhang ◽  
Qiaoling Liu ◽  
Bangchun Wen
Keyword(s):  
Perturbation Method ◽  
Dynamic Characteristics ◽  
Stochastic Perturbation ◽  
Random Excitation ◽  
Numerical Results ◽  
Stochastic Parameters ◽  
Machine Systems ◽  
Random Responses ◽  
Dynamics Problems ◽  
Stochastic Perturbation Method

This paper presents the dynamics problems of stochastic vibratory machine systems. The random responses of the vibratory machine systems with stochastic parameters subjected to random excitation are researched using a stochastic perturbation method. The numerical results are obtained. The dynamic characteristics of nonlinear stochastic vibratory machine are analyzed.

scholarly journals Energy Fluctuations in the Homogenized Hyper-Elastic Particulate Composites with Stochastic Interface Defects

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2011
Author(s):  
Damian Sokołowski ◽  
Marcin Kamiński ◽  
Artur Wirowski
Keyword(s):  
Perturbation Method ◽  
Volume Fraction ◽  
Stochastic Perturbation ◽  
Fem Analysis ◽  
Spherical Shape ◽  
Deformation Energy ◽  
Particulate Composites ◽  
Interface Defects ◽  
Hyper Elastic ◽  
Stochastic Perturbation Method

The principle aim of this study is to analyze deformation energy of hyper-elastic particulate composites, which is the basis for their further probabilistic homogenization. These composites have some uncertain interface defects, which are modelled as small semi-spheres with random radius and with bases positioned on the particle-matrix interface. These defects are smeared into thin layer of the interphase surrounding the reinforcing particle introduced as the third component of this composite. Matrix properties are determined from the experimental tests of Laripur LPR 5020 High Density Polyurethane (HDPU). It is strengthened with the Carbon Black particles of spherical shape. The Arruda–Boyce potential has been selected for numerical experiments as fitting the best stress-strain curves for the matrix behavior. A homogenization procedure is numerically implemented using the cubic Representative Volume Element (RVE). Spherical particle is located centrally, and computations of deformation energy probabilistic characteristics are carried out using the Iterative Stochastic Finite Element Method (ISFEM). This ISFEM is implemented in the algebra system MAPLE 2019 as dual approach based upon the stochastic perturbation method and, independently, upon a classical Monte-Carlo simulation, and uniform uniaxial deformations of this RVE are determined in the system ABAQUS and its 20-noded solid hexahedral finite elements. Computational experiments include initial deterministic numerical error analysis and the basic probabilistic characteristics, i.e., expectations, deviations, skewness and kurtosis of the deformation energy. They are performed for various expected values of the defects volume fraction. We analyze numerically (1) if randomness of homogenized deformation energy can correspond to the normal distribution, (2) how variability of the interface defects volume fraction affects the deterministic and stochastic characteristics of composite deformation energy and (3) whether the stochastic perturbation method is efficient in deformation energy computations (and in FEM analysis) of hyper-elastic media.

Sign in / Sign up

Export Citation Format

Share Document