Force Finding Analysis of Hybrid Space Structures

2005 ◽  
Vol 20 (2) ◽  
pp. 107-113 ◽  
Author(s):  
Zhang Zhi-Hong ◽  
Dong Shi-Lin ◽  
Yukio Tamura
Keyword(s):  
Matrix Theory ◽  
Beam Element ◽  
Local Analysis ◽  
Space Structures ◽  
Analysis Method ◽  
Equilibrium Equations ◽  
Force Finding ◽  
Hybrid Space ◽  
String Structure ◽  
Equilibrium Matrix

Some aspects of the application of the equilibrium matrix theory in hybrid space structures are discussed in this paper. In hybrid space structures that are composed of cables and bars only, the flexibility distribution of each bar element should be considered at the same time. Otherwise the structure would probably not be tensioned and constructed successfully. A method to obtain the flexibility distribution of cable-bar hybrid structures is presented by using compatibility equations and equilibrium equations at the same time. This is verified by two numerical examples (Example 1 and 2). In hybrid space structures composed of beams, cables and bars another problem exists, namely constructing the equilibrium matrix of two-node beam element. There are 6 or 3 columns for each two-node beam element in the whole equilibrium matrix. In the case of a suspen-dome there are lots of independent self-equilibrated stress modes. However, in a beam-string structure there is only one self-equilibrated stress mode. In order to avoid the combination of many independent self-stress modes a method named local analysis method is proposed in this paper to obtain the initial pre-stress distribution of the beams. A small beam-string structure is to verify this method.

Shape Determination of a New Double Inner and Outer Latticed Shell String Structure

2014 ◽  
Vol 501-504 ◽  
pp. 744-747
Author(s):  
Guang Ying Ma ◽  
Yun Long Yao ◽  
Yu Meng Dong
Keyword(s):  
Space Structure ◽  
Local Analysis ◽  
Analysis Method ◽  
Structural System ◽  
Roof Structure ◽  
String Structure ◽  
Roofing Material ◽  
New Type ◽  
Shape Determination

Double inner and outer latticed shell string structure is a new type of space structure. The new structural system is to reduce the space occupied by roof structure and could be laid by the rigid roofing material conveniently. Based on the local analysis method and the whole system balance, a numerical algorithm was introduced and some suggestions for improvement were put forward. An example was investigated and the results confirmed the feasibility of the proposed method.

Initial Prestress Optimization of Tensegrity Structures Based on Fish-Swarm Algorithm

2012 ◽  
Vol 594-597 ◽  
pp. 2922-2926
Author(s):  
Cheng Qing Liu ◽  
Rui Liang ◽  
Wei Xing Shi
Keyword(s):  
Mathematical Model ◽  
Matrix Theory ◽  
Mathematical Optimization ◽  
Tensegrity Structures ◽  
Matlab Program ◽  
Force Finding ◽  
Equilibrium Matrix ◽  
Mathematical Optimization Model ◽  
Swarm Algorithm ◽  
Compression Condition

Several force finding methods for the tensegrity structures, coupled with their limitations, are simply reviewed. Based on the equilibrium matrix theory and the judgment of structure’s geometrical stability, a new mathematical model, which considering the uniformity as well as the tension-compression condition of elements prestress, is proposed in this paper. The author write a corresponding MATLAB program by using the Fish-swarm Algorithm, and an example of multi states of self-stress tensegrity structrue is presented. The results show that the proposed mathematical optimization model can solve the force-finding problem of any multi states of self-stress tensegrity structure accurately and efficiently.

Shape Determination of a New Double Inner and Outer Latticed Shell String Structure

2012 ◽  
Vol 256-259 ◽  
pp. 762-765
Author(s):  
Guang Ying Ma ◽  
Yun Long Yao ◽  
Yu Meng Dong
Keyword(s):  
Space Structure ◽  
Local Analysis ◽  
Analysis Method ◽  
Structural System ◽  
Roof Structure ◽  
String Structure ◽  
Roofing Material ◽  
New Type ◽  
Shape Determination

Double inner and outer latticed shell string structure is a new type of space structure. The new structural system is to reduce the space occupied by roof structure and could be laid by the rigid roofing material conveniently. Based on the local analysis method and the whole system balance, a numerical algorithm was introduced and some suggestions for improvement were put forward. An example was investigated and the results confirmed the feasibility of the proposed method.

Stiffness Update Procedure in Iterative Global-Local Analysis of Columns

2015 ◽  
Author(s):  
R. Emre Erkmen ◽  
Ashkan Afnani ◽  
Vida Niki
Keyword(s):  
Stiffness Matrix ◽  
Beam Element ◽  
Global Model ◽  
Local Analysis ◽  
Element Solution ◽  
Computationally Efficient ◽  
Embedded Discontinuities ◽  
Softening Behaviour ◽  
Number Of Iterations ◽  
Local Deformations

The purpose of this study is to develop a stiffness update technique to be used in a computationally efficient finite element solution for the analysis of columns undergoing local deformations, within the procedure of iterative global-local analysis. The computational problem that arises is that the stiffness matrix is formulated according to the global model, and as a result, considerably large number of iterations is required when the local deformations are significant. To overcome this difficulty, a stiffness update technique is presented in which the displacement field of the global model is altered at each step to consider the locally induced softening behaviour in order to accelerate the convergence. This goal is achieved by introducing embedded discontinuities in the beam element.

Dynamic Response Analysis of Bridge Pier Subject to Earthquake and Ice Loads

2011 ◽  
Vol 250-253 ◽  
pp. 2211-2215
Author(s):  
Fu Qiang Qi
Keyword(s):  
Dynamic Response ◽  
Dynamic Equilibrium ◽  
Work Conditions ◽  
Bridge Pier ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Analysis Method ◽  
Equilibrium Equations ◽  
Different Types ◽  
Ice Loads

In order to discuss the effect of earthquake and dynamic ice loads to a bridge pier, this paper considered the effect of added mass of dynamic water, and it deduced the dynamic equilibrium equations for a bridge pier subject to earthquake and dynamic ice loads on the basis of nonlinear Morision equation. Using numerical analysis method, it discussed the dynamic response of a bridge pier subject to different types of earthquake loads, forced ice loads, and both earthquake and forced ice loads. Through comparing the pier responses in different work conditions, it discovered that the dynamic responses of the bridge pier subject to forced dynamic ice loads rise and fall severely at the time of ice buckling broken periodic change. The coupling effects of forced dynamic ice loads and earthquake especially near-fault earthquake enhance the dynamic response of bridge pier significantly.

Different Features of a Stability Problem of Underconstrained Structures

1997 ◽  
Vol 64 (4) ◽  
pp. 923-928
Author(s):  
K. Y. Volokh ◽  
O. Vilnay
Keyword(s):  
Stability Problem ◽  
Equilibrium Equations ◽  
Matrix Rank ◽  
Numerical Examples ◽  
Overall Stability ◽  
Equilibrium Matrix ◽  
Theoretical Considerations

Stability problem of bearing pin-jointed assemblies, in which the number of equilibrium equations is greater than the equilibrium matrix rank (underconstrained structures), is investigated. Local and overall stability of initial and loaded states are discussed. Theoretical considerations are accompanied by numerical examples.

On the rigidity of triangulated hyperbolic paraboloids

1988 ◽  
Vol 418 (1855) ◽  
pp. 425-452 ◽  
Keyword(s):  
Three Dimensional ◽  
Load Test ◽  
Equilibrium Equations ◽  
Triangulated Surfaces ◽  
Historic Review ◽  
Equilibrium Matrix ◽  
Geometric Arrangements ◽  
Hyperbolic Paraboloids

The paper investigates the rigidity of two classes of three-dimensional pin-jointed assemblies which describe triangulated surfaces of hyperbolic paraboloidal shape: type 1 with straight boundaries, and type 2 with parabolic boundaries. The two arrangements have identical horizontal plans. The investigation begins with a brief historic review of techniques for detecting lack of rigidity. The behaviour of both type-1 and type-2 assemblies depends on the number n of bars on each edge of the structure and, although both geometric arrangements satisfy Maxwell rule (3 j ═ b , where j is the number of joints and b is the number of bars) for any value of n , all type-1 assemblies with n even and greater than 2 and type-2 assemblies with n > 1 are in fact not rigid. This result is first proved for some specific cases by the zero-load test; and then for arbitrary values of n . The equilibrium equations of each joint are written down in terms of a stress function, and are then assembled in an equilibrium matrix whose rank is found by general matrix manipulations. The number of inextensional mechanisms and static redundancies is also obtained. The rigidity of assemblies consisting of four interconnected type-1 hyperbolic paraboloidal sheets is also discussed, and it is concluded that they are equally prone to the same kind of misbehaviour.

The Presentation of Biorthogonal Non-Tensor Trivariate Wavelet Wraps in Besov Space

2012 ◽  
Vol 461 ◽  
pp. 738-742
Author(s):  
De Lin Hua
Keyword(s):  
Besov Space ◽  
Frequency Analysis ◽  
Iteration Method ◽  
Filter Bank ◽  
Matrix Theory ◽  
Analysis Method ◽  
Analogy Method ◽  
Time Frequency ◽  
Orthonormal Bases ◽  
Vector Valued

In this paper, the concept of orthogonal non-tensor bivariate wavelet packs, which is the generalization of orthogonal univariate wavelet packs, is pro -posed by virtue of analogy method and iteration method. Their orthogonality property is investigated by using time-frequency analysis method and variable se-paration approach. Three orthogonality formulas regarding these wavelet wraps are established. Moreover, it is shown how to draw new orthonormal bases of space from these wavelet wraps. A procedure for designing a class of orthogonal vector-valued finitely supported wavelet functions is proposed by virtue of filter bank theory and matrix theory.

Specific Properties of a King of Trivariable Wavelet Packets with Respect to an Integer-Valued Dilation Matrix

2010 ◽  
Vol 439-440 ◽  
pp. 1141-1146
Author(s):  
Jin Cang Han ◽  
Yang Li
Keyword(s):  
Finite Group ◽  
Group Theory ◽  
Frequency Analysis ◽  
Matrix Theory ◽  
Wavelet Packets ◽  
Analysis Method ◽  
Time Frequency ◽  
Finite Group Theory ◽  
Dilation Matrix ◽  
Vector Valued

In the work, the concept of orthogonal vector-valued trivariate wavelet packets, which is a generalization of uniwavelet packets, is introduced. A new method for constructing them is developed, and their characteristics is discussed by using time-frequency analysis method, matrix theory and finite group theory. Orthogonality formulas are established.

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