An efficient method for flutter stability analysis of aeroelastic systems considering uncertainties in aerodynamic and structural parameters

2019 ◽  
Vol 126 ◽  
pp. 407-426 ◽  
Author(s):  
Yuning Zheng ◽  
Zhiping Qiu
Keyword(s):  
Stability Analysis ◽  
Efficient Method ◽  
Structural Parameters

Study of Evaluation Method in Terms of Structural Planes Mechanical Characteristics in Engineering Rock Mass

2013 ◽  
Vol 353-356 ◽  
pp. 384-387 ◽  
Author(s):  
Mu Dan Guo ◽  
Fu Sheng Zhu ◽  
Shu Hong Wang ◽  
Xi Jiang Mu
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Efficient Method ◽  
Weight Distribution ◽  
Evaluation Method ◽  
Mechanical Characteristics ◽  
Significant Issue ◽  
Analytic Hierarchy ◽  
Intensity Parameters ◽  
Hierarchy Process

Study of mechanical characteristics of structural planes has been significant issue in engineering rock mass stability analysis. The factors that affect the mechanical behavior of structural planes are so complicated that it is quite essential to take an efficient method to quantificationally analyze these factors. Based on the basic principals of analytic hierarchy process (AHP), a structural plane classification method-CSPC method is proposed. It can conduct weight distribution in terms of the complicated factors, assess the structural planes comprehensively and also forecast the planes intensity parameters semiquantitatively. The classification and forecast parameters of structural planes appropriately fit the cases in engineering. Furthermore, the method is easy to master for the engineers and the application can be of great prospect.

A Novel Ortho-Triplex Tensegrity Derived by the Linkage-Truss Transformation With Prestress-Stability Analysis Using Screw Theory

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Liheng Wu ◽  
Jian S. Dai
Keyword(s):  
Stability Analysis ◽  
Quadratic Form ◽  
Screw Theory ◽  
Structural Parameters ◽  
Triangular Prism ◽  
Tensegrity Structures ◽  
Tensegrity Structure ◽  
Revolute Joints ◽  
Rigidity Analysis

Abstract This paper presents a novel tensegrity structure derived from the tensegrity triplex (also called the simplex or regular triangular prism) by using the linkage-truss transformation. In this paper, the tensegrity triplex is first transformed into a 6R linkage with vertical members as revolute joints and is coined the triplex linkage. With this, a novel 6R linkage was derived, whose joint axes are perpendicular to the joint axes of the triplex linkage and is coined the ortho-triplex linkage. Rigidity analysis based on screw theory demonstrates that both obtained linkages with infinitesimal mobility are prestress stable. Finally, transforming the ortho-triplex linkage to a truss, by using cables for tensional members and struts for compressional members, leads to a novel tensegrity that is coined ortho-triplex tensegrity. A non-dimensional quadratic form is further provided to analyze the sensitivity of prestress-stability in terms of the structural parameters. The process of derivation of this novel tensegrity presents a new way of designing tensegrity structures with prestress-stability analysis based on screw theory.

Buckling Stability Analysis of Micro Spring

2014 ◽  
Vol 513-517 ◽  
pp. 4188-4192
Author(s):  
Zhen Wang ◽  
Li Sui ◽  
Geng Chen Shi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stability Analysis ◽  
Design Process ◽  
Structural Parameters ◽  
Normal Function ◽  
Proper Function ◽  
Buckling Stability ◽  
Modeling Software ◽  
Critical Buckling Pressure

Micro springs are often served in the fuzes MEMS-based safe and arm systems as force and energy transmission elements, which are critical to guarantee the fuze safe and arm systems' safety in normal time and proper function after launching. While the micro springs are easy to get buckled under pressure thus influence the normal function, to avoid that, the relationships between the critical buckling pressure and the structural parameters were taken into consideration in the design process. Taking the S-shaped micro spring as example, models were built using modeling software Inventor and eigenvalue buckling analysis was performed with the FEM (finite-element method) software ANSYS, hence the relationships between the critical buckling pressure and the structural parameters of the micro spring in certain conditions were obtained.

Buckling Stability Analysis of Parallel Micro-Spring

2014 ◽  
Vol 989-994 ◽  
pp. 2859-2864
Author(s):  
Jing Zhang ◽  
Li Sui ◽  
Xu Hong Guo ◽  
Guo Hua Liu
Keyword(s):  
Stability Analysis ◽  
Critical Load ◽  
Critical Loads ◽  
Structural Parameters ◽  
Buckling Analysis ◽  
Buckling Mode ◽  
Compression Deformation ◽  
Buckling Stability

Compression deformation will cause a micro-spring to buckle, and structural parameters, constraint conditions and structural forms of a micro-spring will affect its critical load and buckling mode. In order to study the influence on the micro-spring’s stability caused by structural forms and find a structure to improve its critical load in the end, this paper designs a new kind of parallel micro-springs, which consists of two same-structured S-shaped planar micro-springs. We have carried on eigenvalue buckling analysis on the parallel micro-spring by software ANSYS, and have gotten its six orders’ buckling mode. Because the critical load of the parallel micro-spring may change with the length of the beam connecting the two sub-springs, this paper studies the effect of the beam’s length on the parallel micro-spring’s critical loads and buckling mode. From comparing the analysis results between parallel micro-spring and single micro-spring with same stiffness, this paper concludes the stability’s degree of improvement.

scholarly journals Examining the Chaotic Behavior in Dynamical Systems by Means of the 0-1 Test

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Loukas Zachilas ◽  
Iacovos N. Psarianos
Keyword(s):  
Stability Analysis ◽  
Dynamical Systems ◽  
Hamiltonian Systems ◽  
Efficient Method ◽  
Toda Lattice ◽  
Good Accuracy ◽  
Chaotic Behavior ◽  
Characteristic Number ◽  
The Stability ◽  
Lyapunov Characteristic Number

We perform the stability analysis and we study the chaotic behavior of dynamical systems, which depict the 3-particle Toda lattice truncations through the lens of the 0-1 test, proposed by Gottwald and Melbourne. We prove that the new test applies successfully and with good accuracy in most of the cases we investigated. We perform some comparisons of the well-known maximum Lyapunov characteristic number method with the 0-1 method, and we claim that 0-1 test can be subsidiary to the LCN method. The 0-1 test is a very efficient method for studying highly chaotic Hamiltonian systems of the kind we study in our paper and is particularly useful in characterizing the transition from regularity to chaos.

scholarly journals Stability Analysis of a Compliant Lemon Bore Journal Bearing

2008 ◽  
Author(s):  
Evgeny Kuznetsov ◽  
Sergei Glavatskih
Keyword(s):  
Stability Analysis ◽  
Efficient Method ◽  
Journal Bearing ◽  
Oil Film ◽  
Dynamic Coefficients ◽  
Ptfe Surface

Dynamic coefficients for a lemon bore journal bearing with a compliant PTFE surface are computed. An efficient method for the calculation of bearing dynamic coefficients proposed by Lund [4] has been extended to compliant bearings. Comparison with a rigid babbitted lemon bore journal bearing in terms of dynamic coefficients and stability is given and discussed. It is shown that it is important to consider perturbations of both the oil film and the compliant lining to obtain realistic results. It is also shown that stability of compliant bearings is improved at some eccentricities compared with conventional babbitted bearings.

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