Nonlinear Dynamic Response of a Simple Ice-Structure Interaction Model

1993 ◽  
Vol 115 (4) ◽  
pp. 246-252 ◽  
Author(s):  
D. G. Karr ◽  
A. W. Troesch ◽  
W. C. Wingate
Keyword(s):  
Dynamic Response ◽  
Nonlinear Dynamic ◽  
Initial Conditions ◽  
Ice Sheet ◽  
Interaction Model ◽  
Offshore Structure ◽  
Analogue Model ◽  
Nonlinear Dynamic Response ◽  
Structure Interaction ◽  
Highly Nonlinear

The problem addressed is the continuous indentation of a ship or offshore structure into an ice sheet. The impacting ship or offshore structure is represented by a mass-spring-dashpot system having a constant velocity relative to the ice sheet. The dynamic response of this simple analogue model of ice-structure interaction is studied in considerable detail. The complicated, highly nonlinear dynamic response is due to intermittent ice breakage and intermittent contact of the structure with the ice. Periodic motions are found and the periodicity for a particular system is dependent upon initial conditions. For a representative system, a Poincare´ map is presented showing the fixed points. A description of some of the effects of random variations in system parameters is also presented. Some implications of these findings regarding structural design for ice interaction are discussed.

scholarly journals A Multi-Scale Approach for Nonlinear Dynamic Response Predictions With Fretting Wear

2016 ◽  
Author(s):  
J. Armand ◽  
L. Pesaresi ◽  
L. Salles ◽  
C. W. Schwingshackl
Keyword(s):  
Dynamic Response ◽  
Nonlinear Dynamic ◽  
Accurate Prediction ◽  
Fretting Wear ◽  
Contact Interface ◽  
Contact Conditions ◽  
Nonlinear Dynamic Response ◽  
Multi Scale ◽  
Highly Nonlinear ◽  
The Impact

Accurate prediction of the vibration response of aircraft engine assemblies is of great importance when estimating both the performance and the lifetime of its individual components. In the case of underplatform dampers, for example, the motion at the frictional interfaces can lead to a highly nonlinear dynamic response and cause fretting wear at the contact. The latter will change the contact conditions of the interface and consequently impact the nonlinear dynamic response of the entire assembly. Accurate prediction of the nonlinear dynamic response over the lifetime of the assembly must include the impact of fretting wear. A multi-scale approach that incorporates wear into the nonlinear dynamic analysis is proposed, and its viability is demonstrated for an underplatform damper system. The nonlinear dynamic response is calculated with a multiharmonic balance approach, and a newly developed semi-analytical contact solver is used to obtain the contact conditions at the blade-damper interface with high accuracy and low computational cost. The calculated contact conditions are used in combination with the energy wear approach to compute the fretting wear at the contact interface. The nonlinear dynamic model of the blade-damper system is then updated with the worn profile and its dynamic response is recomputed. A significant impact of fretting wear on the nonlinear dynamic behaviour of the blade-damper system was observed, highlighting the sensitivity of the nonlinear dynamic response to changes at the contact interface. The computational speed and robustness of the adopted multi-scale approach are demonstrated.

scholarly journals A Multiscale Approach for Nonlinear Dynamic Response Predictions With Fretting Wear

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
J. Armand ◽  
L. Pesaresi ◽  
L. Salles ◽  
C. W. Schwingshackl
Keyword(s):  
Dynamic Response ◽  
Nonlinear Dynamic ◽  
Accurate Prediction ◽  
Fretting Wear ◽  
Multiscale Approach ◽  
Contact Interface ◽  
Contact Conditions ◽  
Nonlinear Dynamic Response ◽  
Highly Nonlinear ◽  
The Impact

Accurate prediction of the vibration response of aircraft engine assemblies is of great importance when estimating both the performance and the lifetime of their individual components. In the case of underplatform dampers, for example, the motion at the frictional interfaces can lead to a highly nonlinear dynamic response and cause fretting wear at the contact. The latter will change the contact conditions of the interface and consequently impact the nonlinear dynamic response of the entire assembly. Accurate prediction of the nonlinear dynamic response over the lifetime of the assembly must include the impact of fretting wear. A multiscale approach that incorporates wear into the nonlinear dynamic analysis is proposed, and its viability is demonstrated for an underplatform damper system. The nonlinear dynamic response is calculated with a multiharmonic balance approach, and a newly developed semi-analytical contact solver is used to obtain the contact conditions at the blade–damper interface with high accuracy and low computational cost. The calculated contact conditions are used in combination with the energy wear approach to compute the fretting wear at the contact interface. The nonlinear dynamic model of the blade–damper system is then updated with the worn profile and its dynamic response is recomputed. A significant impact of fretting wear on the nonlinear dynamic behavior of the blade–damper system was observed, highlighting the sensitivity of the nonlinear dynamic response to changes at the contact interface. The computational speed and robustness of the adopted multiscale approach are demonstrated.

GLOBAL CONTACT DYNAMICS OF AN ICE-STRUCTURE INTERACTION MODEL

1992 ◽  
Vol 02 (03) ◽  
pp. 607-620 ◽  
Author(s):  
ARMIN W. TROESCH ◽  
DALE G. KARR ◽  
KLAUS-PETER BEIER
Keyword(s):  
Dynamical System ◽  
Global Analysis ◽  
Ice Sheet ◽  
Interaction Model ◽  
Contact Dynamics ◽  
Total System ◽  
Numerical Techniques ◽  
Analogue Model ◽  
Structure Interaction ◽  
Basin Boundaries

The interaction between a moving ice sheet and an elastic structure is studied using the analogue model of Matlock, et al. [1969]. The ice sheet is represented by a series of teeth with bilinear, discontinuous stiffness. A global analysis of the resulting dynamical system is performed. Using a combination of analytical and numerical techniques, periodic solutions are determined and basin boundaries of the Poincaré map identified. While the total system dynamics are quite complex, two types of threshold solutions are found, each necessary but not sufficient in defining local separatrices.

Analysis of Nonlinear Dynamic Response of Wind Turbine Blade Under Fluid–Structure Interaction and Turbulence Effect

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Jianping Zhang ◽  
Kaige Zhang ◽  
Aixi Zhou ◽  
Tingjun Zhou ◽  
Danmei Hu ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Nonlinear Dynamic ◽  
Fluid Structure Interaction ◽  
Wind Turbine Blade ◽  
Response Curves ◽  
Nonlinear Dynamic Response ◽  
Structure Interaction ◽  
Turbulence Effect

In this paper, the entity model of a 1.5 MW offshore wind turbine blade was built by Pro/Engineer software. Fluid flow control equations described by arbitrary Lagrange–Euler (ALE) were established, and the theoretical model of geometrically nonlinear vibration characteristics under fluid–structure interaction (FSI) was given. The simulation of offshore turbulent wind speed was achieved by programming in Matlab. The brandish displacement, the Mises stress distribution and nonlinear dynamic response curves were obtained. Furthermore, the influence of turbulence and FSI on blade dynamic characteristics was studied. The results show that the response curves of maximum brandish displacement and maximum Mises stress present the attenuation trends. The region of the maximum displacement and maximum stress and their variations at different blade positions are revealed. It was shown that the contribution of turbulence effect (TE) on displacement and stress is smaller than that of the FSI effect, and its extent of contribution is related to the relative span length. In addition, it was concluded that the simulation considering bidirectional FSI (BFSI) can reflect the vibration characteristics of wind turbine blades more accurately.

Effect of Soil–Structure Interaction on Nonlinear Dynamic Response of Reinforced Concrete Structures

2020 ◽  
Vol 20 (13) ◽  
pp. 2041013
Author(s):  
Christos Mourlas ◽  
Neo Khabele ◽  
Hussein A. Bark ◽  
Dimitris Karamitros ◽  
Francesca Taddei ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Dynamic Loading ◽  
Nonlinear Dynamic ◽  
Soil Structure ◽  
Soil Structure Interaction ◽  
Nonlinear Dynamic Response ◽  
Rc Structures ◽  
Structure Interaction ◽  
Fixed Base ◽  
Dynamic Loading Conditions

Investigating the nonlinear dynamic response of reinforced concrete (RC) structures is of significant importance in understanding the expected behavior of these structures under dynamic loading. This becomes more crucial during the design of new or the assessment of the existing RC structures that are located in seismically active areas. The numerical simulation of this problem through the use of detailed 3D modeling is still a subject that has not been investigated thoroughly due to the significant challenges related to numerical instabilities and excessive computational demand, especially when the soil–structure interaction (SSI) phenomenon is accounted for. This study aims at presenting a nonlinear simulation tool to investigate this numerically cumbersome problem in order to provide further inside into the SSI effect on RC structures under nonlinear dynamic loading conditions. A detailed 3D numerical model of full-scale RC structures considering the SSI effect through modeling the nonlinear frame and soil domain is performed and discussed herein. The constructed models are subjected to dynamic loading conditions and an elaborate investigation is presented considering different type of structures, material properties of soil domains and depths. The RC structures and the soil domains are modeled through 8-noded hexahedral isoparametric elements, where the steel bar reinforcement of concrete is modeled as embedded beam and truss finite elements. The Ramberg–Osgood constitutive law was used for modeling the soil domain. It was shown that the SSI effect can significantly increase the flexibility of the system, altering the nonlinear dynamic response of the RC frames causing local damages that are not observed when the fixed-base model is analyzed. Furthermore, it was found that the structures founded on soft soil developed larger base-shear compared to the fixed-base model which is attributed to resonance phenomena connected to the SSI effect and the imposed accelerograms.

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