Efficient Nonstationary Stochastic Response Analysis for Linear and Nonlinear Structures by FFT

2019 ◽  
Vol 145 (5) ◽  
pp. 04019023 ◽  
Author(s):  
Ning Zhao ◽  
Guoqing Huang
Keyword(s):  
Response Analysis ◽  
Nonlinear Structures ◽  
Stochastic Response ◽  
Linear And Nonlinear

scholarly journals Complex response analysis of a non-smooth oscillator under harmonic and random excitations

2021 ◽  
Vol 42 (5) ◽  
pp. 641-648
Author(s):  
Shichao Ma ◽  
Xin Ning ◽  
Liang Wang ◽  
Wantao Jia ◽  
Wei Xu
Keyword(s):  
Excitation Frequency ◽  
System Stability ◽  
Response Analysis ◽  
External Excitation ◽  
Stochastic Response ◽  
Impact Oscillator ◽  
Nonlinear Parameters ◽  
Bifurcation Phenomena ◽  
Mc Simulation ◽  
Smooth System

AbstractIt is well-known that practical vibro-impact systems are often influenced by random perturbations and external excitation forces, making it challenging to carry out the research of this category of complex systems with non-smooth characteristics. To address this problem, by adequately utilizing the stochastic response analysis approach and performing the stochastic response for the considered non-smooth system with the external excitation force and white noise excitation, a modified conducting process has proposed. Taking the multiple nonlinear parameters, the non-smooth parameters, and the external excitation frequency into consideration, the steady-state stochastic P-bifurcation phenomena of an elastic impact oscillator are discussed. It can be found that the system parameters can make the system stability topology change. The effectiveness of the proposed method is verified and demonstrated by the Monte Carlo (MC) simulation. Consequently, the conclusions show that the process can be applied to stochastic non-autonomous and non-smooth systems.

Sensitivity analysis of geotechnical site conditions effect on the seismic response of a saturated inhomogeneous poroviscoelastic soil profile

2018 ◽  
Vol 15 (6) ◽  
pp. 661-677 ◽  
Author(s):  
Toufiq Ouzandja ◽  
Mohamed Hadid
Keyword(s):  
Soil Properties ◽  
Seismic Response ◽  
Pore Water ◽  
Soil Profile ◽  
Water Saturation ◽  
Free Field ◽  
Response Spectra ◽  
Response Analysis ◽  
Content Type ◽  
Linear And Nonlinear

Purpose This paper aims to present the investigation of the linear and nonlinear seismic site response of a saturated inhomogeneous poroviscoelastic soil profile for different soil properties, such as pore-water saturation, non-cohesive fines content FC, permeability k, porosity n and coefficient of uniformity Cu. Design/methodology/approach The inhomogeneous soil profile is idealized as a multi-layered saturated poroviscoelastic medium and is characterized by the Biot’s theory, with a shear modulus varying continuously with depth according to the Wichtmann’s model. Seismic response analysis has been evaluated through a computational model, which is based on the exact stiffness matrix method formulated in the frequency domain assuming that the incoming seismic waves consist of inclined P-SV waves. Findings Unlike the horizontal seismic response, the results indicate that the vertical one is strongly affected by the pore water saturation. Moreover, in the case of fully saturated soil profile, the same vertical response spectra are found for the two cases of soil behavior, linear and nonlinear. Originality/value This research is a detailed study of the geotechnical soil properties effect on the bi-directional seismic response of saturated inhomogeneous poroviscoelastic soil profile, which has not been treated before; the results are presented in terms of the peak acceleration ratio, as well as the free-field response spectra and the spectral ratio (V/H).

Stochastic Response Analysis and Reliability-Based Design Optimization of Nonlinear Electromechanical Energy Harvesters with Fractional Derivative Elements

2020 ◽  
Author(s):  
Ioannis Petromichelakis ◽  
Apostolos F. Psaros ◽  
Ioannis A. Kougioumtzoglou
Keyword(s):  
Fractional Derivative ◽  
Design Optimization ◽  
Response Analysis ◽  
Reliability Based Design Optimization ◽  
Stochastic Response ◽  
Energy Harvesters ◽  
Reliability Based Design ◽  
Singular Diffusion ◽  
Electromechanical Energy ◽  
Definition Of

Abstract A methodology based on the Wiener path integral technique (WPI) is developed for stochastic response determination and reliability-based design optimization of a class of nonlinear electromechanical energy harvesters endowed with fractional derivative elements. In this regard, first, the WPI technique is appropriately adapted and enhanced to account both for the singular diffusion matrix and for the fractional derivative modeling of the capacitance in the coupled electromechanical governing equations. Next, a reliability-based design optimization problem is formulated and solved, in conjunction with the WPI technique, for determining the optimal parameters of the harvester. It is noted that the herein proposed definition of the failure probability constraint is particularly suitable for harvester configurations subject to space limitations. Several numerical examples are included, while comparisons with pertinent Monte Carlo simulation data demonstrate the satisfactory performance of the methodology.

scholarly journals Stochastic Response of Tension Leg Platform to Wave and Current Forces

1989 ◽  
Vol 111 (4) ◽  
pp. 221-230 ◽  
Author(s):  
A. Ertas ◽  
J.-H. Lee
Keyword(s):  
Constant Current ◽  
Response Analysis ◽  
Stochastic Dynamic ◽  
Superposition Method ◽  
Random Waves ◽  
Stochastic Response ◽  
Tension Leg Platform ◽  
Single Degree Of Freedom ◽  
Simulation Techniques ◽  
Wave Induced

The linear analysis in the frequency domain is presented for the surge motion of a tension leg platform (TLP) in the case of random waves only and random waves with constant current. A single-degree-of-freedom model of a TLP is employed for response. The superposition method, one of the simulation techniques, is applied to random sea wave, and the response analysis of TLP in time is developed with wave velocity and wave acceleration simulations. Wave-induced forces are calculated using the modified Morison equation, which takes into account relative motion. Computational methods for both analyses are developed, and the results of stochastic, dynamic response of the TLP, with and without the presence of current, are presented and compared.

A hybrid method for stochastic response analysis of a vibrating structure

2015 ◽  
Vol 85 (11) ◽  
pp. 1607-1626
Author(s):  
Soumyadipta Sarkar ◽  
Debraj Ghosh
Keyword(s):  
Hybrid Method ◽  
Response Analysis ◽  
Stochastic Response
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