Self-Locking Satellite Boom With Flexure-Mode Joints

1997 ◽  
Vol 50 (11S) ◽  
pp. S225-S231 ◽  
Author(s):  
W. Szyszkowski ◽  
K. Fielden ◽  
D. W. Johnson
Keyword(s):  
Nonlinear Dynamics ◽  
Numerical Simulation ◽  
Dynamic Analysis ◽  
Large Deflection ◽  
Cylindrical Shells ◽  
Experimental Results ◽  
Large Deflections ◽  
Large Rotations

Dynamic analysis, numerical simulation, and experimental results of the deployment of a self-locking lightweight satellite boom are presented. The joints that connect the two segments of the boom are made of flexible semi-cylindrical shells. During the deployment, the shells undergo large deflections and large rotations, up to π radians. The boom is to be launched in the folded configuration and then deployed from a rotating satellite. In the straight configuration, after locking the joints, the boom should be stiff enough to precisely position a heavy sensor in a required location. Several models of the boom are considered for analysis. In order to optimize the sensor trajectory and the locking sequence, a model that includes stiffness of the joints but neglects flexibility of the links is developed. The joints, which are prone to instabilities and snap-through behavior, are analyzed using large deflection quasistatic approach. Finally, nonlinear dynamics FEA is performed to simulate the deployment of the complete boom. The simulation is compared with experimental results obtained from the preliminary tests.

Large deflection of plates and beams obeying non-linear stress—strain laws

1974 ◽  
Vol 9 (3) ◽  
pp. 178-184 ◽  
Author(s):  
K R Rushton ◽  
P M Hook
Keyword(s):  
Finite Difference ◽  
Large Deflection ◽  
Experimental Results ◽  
Large Deflections ◽  
Rectangular Plates ◽  
Dynamic Relaxation ◽  
Stress Strain ◽  
Finite Difference Technique ◽  
Non Linear ◽  
Alternative Solutions

The large deflections of rectangular plates and beams obeying a non-linear stress-strain law are examined. Solutions are obtained by use of dynamic relaxation, a numerical finite-difference technique. Comparisons are made with alternative solutions and experimental results. The effects of varying parameters in the non-linear expressions are considered.

STATIC AND DYNAMIC ANALYSIS OF FLEXIBLE BEAMS: A CONSISTENT UPDATED LAGRANGIAN FORMULATION

1997 ◽  
Vol 21 (2) ◽  
pp. 141-177 ◽  
Author(s):  
K. Behdinan ◽  
M.C. Stylianou ◽  
B. Tabarrok
Keyword(s):  
Dynamic Analysis ◽  
Large Deflections ◽  
Flexible Beams ◽  
Static And Dynamic Analysis ◽  
Small Strains ◽  
Large Rotations ◽  
Slender Beams ◽  
Updated Lagrangian Formulation ◽  
Updated Lagrangian ◽  
Rotational Method

A study of static and dynamic analysis of slender beams undergoing large deflections is undertaken here. the Euler-Bernoulli hypothesis is employed and the beam deforms with large rotations but small strains. Initially the static analysis, using the consistent updated Lagrangian techniques which accounts for full non-linearity of the beam is undertaken and is then extended to dynamic analysis. Several examples illustrating the implementation and the performance of the proposed formulation are included and a comparison with results obtained by the co-rotational method is provided.

Dynamic Analysis of Rubbing Rotor System Based on Hertz Contact Theory

2012 ◽  
Vol 479-481 ◽  
pp. 743-747 ◽  
Author(s):  
Yang Liu ◽  
Qin Liang Li ◽  
Ya Zhe Chen ◽  
Bang Chun Wen
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Dynamic Analysis ◽  
Rotor System ◽  
Experimental Results ◽  
Contact Theory ◽  
Force Model ◽  
Hertz Contact ◽  
Hertz Contact Theory ◽  
Model Based

When discussing the rubbing issue of rotor system, the effect of nonlinear rubbing force is needed to be considered. In this paper, modeling and numerical simulation were carried out by using the nonlinear rubbing force based on Hertz contact theory, and researching the dynamic response of fault rotor system in the conditions of the different rubbing stiffness. Through the analysis we found that, in the case of larger rubbing stiffness the result simulated by using rubbing force model based on Hertz contact theory has stronger nonlinear and more obvious rubbing feature, compared to the rubbing model of linear stiffness. It is beneficial to determine the occurrence of rubbing. Refer to the relevant experimental results, the correctness of the Hertz rubbing model and the feasibility of applying it in the modeling of rubbing rotor system were confirmed.

On the Nonlinear Dynamics of a Vibro-Impacting Cantilever With End Mass

2012 ◽  
Author(s):  
Prasanna Gandhi ◽  
Ajinkya Badkas
Keyword(s):  
Nonlinear Dynamics ◽  
Dynamic Analysis ◽  
Frequency Response ◽  
Experimental Results ◽  
Response Curves ◽  
Close Match ◽  
Nonlinear Hysteresis ◽  
Fixed End ◽  
Stop Position ◽  
Harmonic Displacement

A theoretical and experimental dynamic analysis of a vibro-impacting cantilever with end mass is presented in this paper. The cantilever is excited by transverse harmonic displacement given at its fixed end with the help of a shaker. Nonlinearity in dynamics due to impact of cantilever on a motion limiting stop only on one side is considered. Experiments revealed quite interesting nonlinear hysteresis, jump, and drop phenomena in this case. Phenomena are experimentally characterized by varying the position and the gap between the stop and cantilever on a custom-built setup. Vibrating cantilever is modeled using assumed modes method while spring damper model for impacting stop is considered. Simulation and experimental results show close match for the same parameters under various cases of stop position and gap. Results are presented in terms of frequency response curves for range of parameters in non-dimensional form to enable their use in similar other cases.

A New Approach to Large Deflection Analyses of Spherical and Cylindrical Shells

1985 ◽  
Vol 52 (4) ◽  
pp. 872-876 ◽  
Author(s):  
G. C. Sinharay ◽  
B. Banerjee
Keyword(s):  
Spherical Shell ◽  
Large Deflection ◽  
Cylindrical Shells ◽  
Numerical Results ◽  
Shallow Spherical Shell ◽  
Large Deflections ◽  
New Approach ◽  
Edge Conditions

In this paper large deflections of thin elastic shallow spherical shell and cylindrical shells are investigated by a new approach. Numerical results for moveable as well as immoveable edge conditions are presented graphically and compared with other known results.

Dynamic Analysis with Stress Recovery for Functionally Graded Materials: Numerical Simulation and Experimental Benchmarking

2014 ◽  
Vol 2 (1) ◽  
pp. 21
Author(s):  
Carlos Alberto Dutra Fraga Filho ◽  
Fernando César Meira Menandro ◽  
Rivânia Hermógenes Paulino de Romero ◽  
Juan Sérgio Romero Saenz
Keyword(s):  
Numerical Simulation ◽  
Dynamic Analysis ◽  
Functionally Graded Materials ◽  
Functionally Graded ◽  
Stress Recovery ◽  
Graded Materials

Simulation of a Free Standing Riser Model and Validation With Experimental Results

2014 ◽  
Author(s):  
Marcio Yamamoto ◽  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Tomo Fujiwara ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Previous Experiment ◽  
Numerical Results ◽  
Experimental Results ◽  
Previous Article ◽  
Scale Model ◽  
Analysis Software ◽  
Free Standing ◽  
Reduced Scale

In this article, we present the numerical analysis of a Free Standing Riser. The numerical simulation was carried out using a commercial riser analysis software suit. The numerical model’s dimensions were the same of a 1/70 reduced scale model deployed in a previous experiment. The numerical results were compared with experimental results presented in a previous article [1]. Discussion about the model and limitations of the numerical analysis is included.

Nonlinear Dynamics and Application of the Four Dimensional Autonomous Hyper-Chaotic System

2014 ◽  
Author(s):  
Ge Kai ◽  
Wei Zhang
Keyword(s):  
Nonlinear Dynamics ◽  
Numerical Simulation ◽  
Differential Equations ◽  
Chaotic System ◽  
Dynamical Behavior ◽  
Three Dimensional ◽  
Phase Portraits ◽  
State Variables ◽  
Chaotic Motions ◽  
Finance System

In this paper, we establish a dynamic model of the hyper-chaotic finance system which is composed of four sub-blocks: production, money, stock and labor force. We use four first-order differential equations to describe the time variations of four state variables which are the interest rate, the investment demand, the price exponent and the average profit margin. The hyper-chaotic finance system has simplified the system of four dimensional autonomous differential equations. According to four dimensional differential equations, numerical simulations are carried out to find the nonlinear dynamics characteristic of the system. From numerical simulation, we obtain the three dimensional phase portraits that show the nonlinear response of the hyper-chaotic finance system. From the results of numerical simulation, it is found that there exist periodic motions and chaotic motions under specific conditions. In addition, it is observed that the parameter of the saving has significant influence on the nonlinear dynamical behavior of the four dimensional autonomous hyper-chaotic system.

RELIABILITY ASSESSMENT OF AXIALLY COMPRESSED COMPOSITE CYLINDRICAL SHELLS WITH RANDOM IMPERFECTIONS

2011 ◽  
Vol 11 (02) ◽  
pp. 215-236 ◽  
Author(s):  
MATTEO BROGGI ◽  
ADRIANO CALVI ◽  
GERHART I. SCHUËLLER
Keyword(s):  
Mathematical Models ◽  
Axial Compression ◽  
Cylindrical Shells ◽  
Reliability Assessment ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Experimental Results ◽  
Drastic Decrease ◽  
Different Types ◽  
Probability And Statistics

Cylindrical shells under axial compression are susceptible to buckling and hence require the development of enhanced underlying mathematical models in order to accurately predict the buckling load. Imperfections of the geometry of the cylinders may cause a drastic decrease of the buckling load and give rise to the need of advanced techniques in order to consider these imperfections in a buckling analysis. A deterministic buckling analysis is based on the use of the so-called knockdown factors, which specifies the reduction of the buckling load of the perfect shell in order to account for the inherent uncertainties in the geometry. In this paper, it is shown that these knockdown factors are overly conservative and that the fields of probability and statistics provide a mathematical vehicle for realistically modeling the imperfections. Furthermore, the influence of different types of imperfection on the buckling load are examined and validated with experimental results.

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