An Analysis of Guided Motion of a Research Spacecraft with a Solar Sail

2019 ◽  
pp. 94-103
Author(s):  
R.M. Khabibullin ◽  
O.L. Starinova
Keyword(s):  
Mathematical Model ◽  
Optimal Control ◽  
Finite Element ◽  
Finite Element Model ◽  
Coordinate System ◽  
Element Model ◽  
Solar Sail ◽  
Motion Simulation ◽  
Control Laws ◽  
Controlled Motion

The paper considers guided motion of a research spacecraft with a frame-type solar sail. When scheduled turns of the solar sail are performed, disturbing forces appear, the characteristics of which depend on the solar sail design. It is necessary to take into account the design features of the solar sail to analyze the controlled motion of the spacecraft. A finite element model of a frame-type solar sail spacecraft construction is developed. A mathematical model of motion in the combined helio-centric coordinate system is described. Local-optimal control laws of orbit elements maintenance and correction are formulated. The software developed for simulating the motion of a spacecraft with a solar sail in the heliocentric coordinate system is used in this study. The analysis of the data obtained during motion simulation demonstrates the feasibility of using the solar sail technology for interplanetary flights.

scholarly journals Simulation of contact interaction of piezoelectric engine elements

2019 ◽  
Vol 3 (4) ◽  
pp. 222-229
Author(s):  
A. V. Azin ◽  
S. A. Kuznetsov ◽  
S. A. Ponomarev ◽  
S. V. Ponomarev ◽  
S. V. Rikkonen
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Model ◽  
Operation Mode ◽  
Experimental Studies ◽  
Operating Mode ◽  
Element Model ◽  
Piezo Element ◽  
Element Activity ◽  
Piezo Electric

In the article the results of a new type of piezo-electric step-engine research are presented. The original construct of piezo-electric step-engine is contained in special engineering lever called grab device that can organize back and forward rod’s motion with only one piezo element activity. To choose the effective process of piezo-electric step-engine work the mathematical model was created. This mathematical model describes inner piezo-electric step-engine process with features of contact and electroelastic deformation. Using the ANSYS application package, а finite element model of the piezo-electric step-engine has been developed. This finite element model allows estimate the stress-strain state of structural elements of the piezo-electric step-engine and determine the effective step-by-step operation mode of the piezo-electric step-engine. Using the finite element model, the influence of the piezo-electric step-engine operating mode parameters on the amount of displacement of the rod is studied. According to results of experimental studies, the proposed numerical model allows to simulate the dynamic process of step-operation of a piezo-electric step-engine with an error of no more than 6 %. This finite element model include the external load on piezo-electric step-engine and can be used to design piezo-electric step-engine of various fields of application.

A Mathematical Model for Bone Remodeling

1999 ◽  
Author(s):  
Scott J. Hazelwood ◽  
R. Bruce Martin ◽  
Juan J. Rodrigo ◽  
Mark M. Rashid
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Bone Remodeling ◽  
Element Model ◽  
Oscillatory Behavior ◽  
Bone Diseases ◽  
Damage Repair ◽  
Sensitive Behavior

Abstract A bone remodeling algorithm based on disuse and damage repair was developed in this study. Important elements of the bone remodeling process, including the delay between resorption and formation of bone and the resulting porosity, were included in the algorithm. A study of the dynamic response of the algorithm indicated oscillatory behavior for disuse situations and critically sensitive behavior in overload situations beyond a threshold load. Application of the algorithm to a finite element model of the femur reproduced the observed internal structure. The model is being used in further studies to investigate remodeling around implant stems and bone diseases and their treatment.

Numerical Simulation of Solar Array with Shape Memory Alloy in Active Vibration Control

2010 ◽  
Vol 29-32 ◽  
pp. 589-595
Author(s):  
Yong Liang Zhang ◽  
Shou Gen Zhao ◽  
Lun Long ◽  
Kang Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Shape Memory ◽  
Vibration Control ◽  
Closed Loop ◽  
Active Vibration Control ◽  
Element Model ◽  
Solar Array ◽  
Feedback Signal ◽  
Control Laws

The objective of this study is to develop a general design scheme for shape memory alloys (SMA) intelligent structure. The scheme involves dynamic modeling and closed-loop simulation in a finite element environment. First, the structure of multi-body finite element model simulating the real solar array is established. SMA wire is appended on the model. The physical value of the strain, displacement, velocity and acceleration at the sensors locations separately is acted as the feedback signal. The value is multiplied by the control gain to calculate the voltage inputted to SMA wire. The finite element model is then modified to accept control laws and perform closed-loop simulations. Finally numerical examples have demonstrated the efficiency of the vibration control.

Stress Analysis of Underground Arch Structure

2011 ◽  
Vol 243-249 ◽  
pp. 938-941
Author(s):  
Bin He ◽  
Jun Long Lu
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Structural Analysis ◽  
Finite Element Model ◽  
Mathematical Models ◽  
Stress Analysis ◽  
Element Model ◽  
Arch Structure ◽  
The Impact ◽  
Actual Stress

To research the safety of an underground defense project and the impact to other buildings, applying basic mechanics principles, established two types of mathematical model for arch about the project, and analyzed stress in different directions of ground arch structure. The data shows that the results were very different in different mathematical models, and mathematical models should be considered as close to actual stress situation in structural analysis. In the structural analysis involved soil, spatial finite element model is more accurate and reasonable than truss finite element model.

Hysteretic damping characteristics of a mechanical tensioner: Modeling and experimental investigation

2018 ◽  
Vol 233 (7) ◽  
pp. 1890-1902 ◽  
Author(s):  
Hao Zhu ◽  
Yumei Hu ◽  
Yangjun Pi ◽  
Weidong Zhu
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Damping Characteristics ◽  
Hysteretic Damping ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
The Mathematical Model

The aim of this article is to investigate hysteretic damping characteristics of a typical tensioner used in engine accessory drive systems. An experiment device is developed to measure the friction coefficients of three contact pairs within the tensioner. Statistic results of test data show that the friction coefficient is linearly dependent on normal forces, and thus a linear function is used to describe it. An exact mathematical model and an accurate three-dimensional finite element model are proposed in this study to calculate the relationship of friction torque and rotation angle as well as the damping characteristics of the tensioner. The mathematical model and three-dimensional finite element model are verified through an experiment. Comparison indicates that both the mathematical and finite element model can accurately predict the working torque of the tensioner during operation process, while the finite element model has better accuracy in predicting the damping characteristics than the mathematical model.

Finite element modeling of bolted connections

1989 ◽  
Vol 16 (2) ◽  
pp. 172-181 ◽  
Author(s):  
G. Gendron ◽  
D. Beaulieu ◽  
G. Dhatt
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Model ◽  
Key Words ◽  
Mathematical Formulation ◽  
Steel Structures ◽  
Element Model ◽  
Bolted Connections ◽  
Steel Connections ◽  
Future Developments

A finite element model which takes account of plasticity and contact for the behavior of bolted steel connections is presented in this study. The mathematical formulation is first presented, followed by the analysis of two bolted connections and a presentation of the results. Future developments and possible applications are finally described. Key words: steel structures, bolted connections, mathematical model, finite element, nonlinear analysis, plasticity.

scholarly journals Control program for noncoplanar heliocentric flight to Venus of non-perfectly reflecting solar sail spacecraft

2020 ◽  
Vol 18 (4) ◽  
pp. 117-128 ◽  
Author(s):  
R. M. Khabibullin
Keyword(s):  
Thin Film ◽  
Optimal Control ◽  
Control Program ◽  
Solar Sail ◽  
Motion Simulation ◽  
Flight Trajectory ◽  
Control Laws ◽  
Osculating Elements

A noncoplanar controlled heliocentric flight to Venus of a spacecraft with a non-perfectly reflecting solar sail is considered. The aim of the heliocentric flight is to get a spacecraft into Hill sphere of Venus with zero hyperbolic excess velocity. An algorithm has been developed for applying the locally optimal control laws for the fastest change of the osculating elements. Solar sail orientation is controlled by thin-film control elements arranged along the solar sail surface perimeter. The flight trajectory, the control program and the required width and area of thin-film control elements are obtained as a result of motion simulation.

scholarly journals Analytical and Finite Element Modeling of the Dynamic Characteristics of a Linear Feeding Stage with Different Arrangements of Rolling Guides

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jyh-Cheng Chang ◽  
Jui-Pin Hung
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Dynamic Characteristics ◽  
Element Model ◽  
Linear Guide ◽  
Element Modeling ◽  
Positioning Stage ◽  
The Finite Element Model

This study was aimed at investigating the dynamic behaviors of the linear driven feeding stage by means of the analytical and finite element modeling approaches. To assess the dynamic characteristics of the stages with different linear guide arrangements, the finite element model of the stages was created, in which the linear components with rolling interface were accurately modeled based on the Hertzian theory. On the other hand, the analytically mathematical model was derived to determine how the linear guide arrangement affects the dynamic characteristics of the stage. Results of the modal analysis show that the vibration behaviors of the positioning stage are dominated by the rigidity of the linear components and the platform. In addition, comparisons of the results from the two approaches further indicate that the platform rigidity is an important factor determining the accuracy of the prediction of the vibration frequencies by the analytically mathematical model. As a conclusion of the study, the analytically mathematical model can approximate well to the finite element model when the linear stage is designed with appropriate structure rigidity.

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