Publications about Tensegrity
from Web of Knowledge in 2010
Key for Field Tags (PT TI AU ...)
PT |
J |
TI |
Constructing tensegrity structures from one-bar elementary cells |
AU |
Li, Y |
SO |
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES |
VL |
466 |
IS |
2113 |
BP |
45 |
EP |
61 |
PY |
2010 |
TC |
2 |
AB |
This study aimed to develop a method to construct tensegrity structures from elementary cells, defined as structures consisting of only one bar connected with a few strings. Comparison of various elementary cells leads to the further selection of the so-called 'Z-shaped' cell, which contains one bar and three interconnected strings, as the elementary module to assemble the Z-based spatial tensegrity structures. The graph theory is utilized to analyse the topology of strings required to construct this type of tensegrity structures. It is shown that 'a string net can be used to construct a Z-based tensegrity structure if and only if its topology is a simple and bridgeless cubic graph'. Once the topology of strings has been determined, one can easily design the associated tensegrity structure by adding a deterministic number of bars. Two schemes are suggested for this design strategy. One is to enumerate all possible topologies of Z-based tensegrity for a specified number of bars or cells, and the other is to determine the tensegrity structure from a vertex-truncated polyhedron. The method developed in this paper allows us to construct various types of novel tensegrity structures. |
UT |
WOS:000272090800004 |
SN |
1364-5021 |
DI |
10.1098/rspa.2009.0260 |
PT |
J |
TI |
Dihedral 'star' tensegrity structures |
AU |
Zhang, JY |
SO |
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES |
VL |
47 |
IS |
1 |
BP |
1 |
EP |
9 |
PY |
2010 |
TC |
0 |
AB |
This paper presents conditions for self-equilibrium and super stability of dihedral 'star' tensegrity structures, based on their dihedral symmetry. It is demonstrated that the structures are super stable if and only if they have an odd number of struts, and the struts are as close as possible to each other. Numerical investigations show that their prestress stability is sensitive to the geometry realisation. (C) 2010 Published by Elsevier Ltd. |
UT |
WOS:000272694000001 |
SN |
0020-7683 |
DI |
10.1016/j.ijsolstr.2009.05.018 |
PT |
J |
TI |
A simplified strategy for force finding analysis of suspendomes |
AU |
Cao, QS |
SO |
ENGINEERING STRUCTURES |
VL |
32 |
IS |
1 |
BP |
306 |
EP |
318 |
PY |
2010 |
TC |
0 |
AB |
The suspendome has been widely used as the structural roof system of sports buildings in recent years. It is a kind of hybrid space structure composed of an upper rigid single-layer latticed shell and a lower flexible tensegrity (cable-strut) system. The prestress level in the lower cable-strut system is of great significance for the suspendome structure because it has no initial geometric stiffness (for a rib-ring type) before prestress is introduced into the lower tensegrity system. The traditional solution for calculating the self-internal-force mode and the prestress force level (force finding) is somewhat complicated; in general it is based on the Equilibrium Matrix Theory. In the present paper, a simplified computational strategy for the determination of the self-internal-force mode based on the nodal equilibrium is presented for the tensegrity system in a suspendome which is grounded on a newly developed method: the Local Analysis Method. Two types of cable-strut arrangement, the Levy system and the Geiger system, are addressed, and the characteristic of each type is expounded. An analytical solution for the self-internal-force mode of the lower cable-strut system is put forward together with the equivalent nodal force acting on the upper single-layer dome for the two types of cable-strut arrangement. The determination of the prestress level of the lower tensegrity system is then elucidated on the ground of the initial architectural configuration. the counterbalance of the bearing reaction, the equivalent nodal force, and the wind-induced slackening effect. An illustrative example is appended in the end to validate the efficiency of this simplified method. It is shown that force finding, at the viewpoint of structural design, based on this method is of great accuracy and efficiency. The prestress in the outermost ring generally has the highest level among the cable-strut system, and has the most influence on the structural performance of the suspendome. The results from the studies can be referred to not only for direct design use in practical engineering, but also for the design of similar hybrid space structures. (C) 2009 Elsevier Ltd. All rights reserved. |
UT |
WOS:000272956800027 |
SN |
0141-0296 |
DI |
10.1016/j.engstruct.2009.09.017 |
PT |
J |
TI |
Geometry of Configuration Spaces of Tensegrities |
AU |
Doray, F |
SO |
DISCRETE & COMPUTATIONAL GEOMETRY |
VL |
43 |
IS |
2 |
BP |
436 |
EP |
466 |
PY |
2010 |
TC |
0 |
AB |
Consider a graph G with n vertices. In this paper we study geometric conditions for an n-tuple of points in a"e (d) to admit a nonzero self-stress with underlying graph G. We introduce and investigate a natural stratification, depending on G, of the configuration space of all n-tuples in a"e (d) . In particular we find surgeries on graphs that give relations between different strata. Further we discuss questions related to geometric conditions defining the strata for plane tensegrities. We conclude the paper with particular examples of strata for tensegrities in the plane with a small number of vertices. |
UT |
WOS:000273589700017 |
SN |
0179-5376 |
DI |
10.1007/s00454-009-9229-4 |
PT |
J |
TI |
Optimal complexity of deployable compressive structures |
AU |
Skelton, RE |
SO |
JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS |
VL |
347 |
IS |
1 |
BP |
228 |
EP |
256 |
PY |
2010 |
TC |
0 |
AB |
The usual use of fractals involves self-similar geometrical objects to fill a space, where the self similar iterations may continue ad infinitum. This is the first paper to propose the use of self-similar mechanical objects that fill an alloted space, while achieving an invariance property as the self-similar iterations continue (e.g. invariant strength). Moreover, for compressive loads, this paper shows how to achieve minimal mass and invariant strength from self-similar structures. The topology optimization procedure uses self-similar iteration until minimal mass is achieved, and this problem is completely solved, with global optimal solutions given in closed form. The optimal topology remains independent of the magnitude of the load. Mass is minimized subject to yield and/or buckling constraints. Formulas are also given to optimize the complexity of the structure, and the optimal complexity turns out to be finite. That is, a continuum is never the optimal structural for a compressive load under any constraints on the physical dimension (diameter). After each additional self-similar iteration, the number of bars and strings increase, but, for a certain choice of unit topology shown, the total mass of bars and strings decreases. For certain structures, the string mass monotonically increases with iteration, while the bar mass monotonically reduces, leading to minimal total mass in a finite number of iterations, and hence a finite optimal complexity for the structure. The number of iterations required to achieve minimal mass is given explicitly in closed form by a formula relating the chosen unit geometry and the material properties. It runs out that the optimal structures produced by our theory fall in the category of structures we call tensegrity. Hence our self-similar algorithms can generate tensegrity fractals. (c) 2009 The Franklin Institute. Published by Elsevier Ltd. All rights reserved. |
UT |
WOS:000273625200016 |
SN |
0016-0032 |
DI |
10.1016/j.jfranklin.2009.10.010 |
PT |
J |
TI |
Optimal tensegrity structures in bending: The discrete Michell truss |
AU |
Skelton, RE |
SO |
JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS |
VL |
347 |
IS |
1 |
BP |
257 |
EP |
283 |
PY |
2010 |
TC |
0 |
AB |
This paper provides the closed form analytical solution to the problem of minimizing the material volume required to support a given set of bending loads with a given number of discrete structural members, subject to material yield constraints. The solution is expressed in terms of two variables, the aspect ratio, rho(-1), and complexity of the structure, q (the total number of members of the structure is equal to q(q + 1)). The minimal material volume (normalized) is also given in closed form by a simple function of rho and q, namely, V = q(rho(-1/q) - rho(1/q)). The forces for this nonlinear problem are shown to satisfy a linear recursive equation, from node-to-node of the structure. All member lengths are specified by a linear recursive equation, dependent only on the initial conditions involving a user specified length of the structure. The final optimal design is a class 2 tensegrity structure. Our results generate the 1904 results of Michell in the special case when the selected complexity q approaches infinity. Providing the optimum interms of a given complexity has the obvious advantage of relating complexity q to other criteria, such as costs, fabrication issues, and control. If the structure is manufactured with perfect joints (no glue, welding material, etc.), the minimal mass complexity is infinite. But in the presence of any joint mass, the optimal structural complexity is finite, and indeed quite small. Hence, only simple structures (low complexity q) are needed for practical design. (c) 2009 The Franklin Institute. Published by Elsevier Ltd. All rights reserved. |
UT |
WOS:000273625200017 |
SN |
0016-0032 |
DI |
10.1016/j.jfranklin.2009.10.009 |
PT |
J |
TI |
Advanced form-finding of tensegrity structures |
AU |
Tran, HC |
SO |
COMPUTERS & STRUCTURES |
VL |
88 |
IS |
3-4 |
BP |
237 |
EP |
246 |
PY |
2010 |
TC |
2 |
AB |
A numerical method is presented for form-finding of tensegrity structures. The topology and the types of members are the only information that requires in this form-finding process. The eigenvalue decomposition of the force density matrix and the single value decomposition of the equilibrium matrix are performed iteratively to find the feasible sets of nodal coordinates and force densities which satisfy the minimum required rank deficiencies of the force density and equilibrium matrices, respectively. Based on numerical examples it is found that the proposed method is very efficient and robust in searching self-equilibrium configurations of tensegrity structures. (C) 2009 Elsevier Ltd. All rights reserved. |
UT |
WOS:000273857600010 |
SN |
0045-7949 |
DI |
10.1016/j.compstruc.2009.10.006 |
PT |
J |
TI |
Topology design of tensegrity structures via mixed integer programming |
AU |
Ehara, S |
SO |
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES |
VL |
47 |
IS |
5 |
BP |
571 |
EP |
579 |
PY |
2010 |
TC |
1 |
AB |
This paper presents a numerical method for finding a tensegrity structure based on the ground structure method. We first solve a mixed integer programming (MIP) problem which maximizes the number of struts over the self-equilibrium condition of axial forces and the discontinuity condition of struts. Subsequently we solve the minimization problem of the number of cables in order to remove redundant self-equilibrium modes, which is also formulated as an MIP. It is regarded to be advantageous that our method does not require any connectivity information of cables and struts to be known in advance, while the obtained tensegrity structure is guaranteed to satisfy the discontinuity condition of struts rigorously. (C) 2009 Elsevier Ltd. All rights reserved. |
UT |
WOS:000274176400004 |
SN |
0020-7683 |
DI |
10.1016/j.ijsolstr.2009.10.020 |
PT |
J |
TI |
On the singularities of a constrained (incompressible-like) tensegrity-cytoskeleton model under equitriaxial loading |
AU |
Pirentis, AP |
SO |
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES |
VL |
47 |
IS |
6 |
BP |
759 |
EP |
767 |
PY |
2010 |
TC |
1 |
AB |
Singularity theory is applied for the study of the characteristic three-dimensional tensegrity-cytoskeleton model after adopting an incompressibility constraint. The model comprises six elastic bars interconnected with 24 elastic string members. Previous studies have already been performed on non-constrained systems; however, the present one allows for general non-symmetric equilibrium configurations. Critical conditions for branching of the equilibrium are derived and post-critical behaviour is discussed. Classification of the simple and compound singularities of the total potential energy function is effected. The theory is implemented into the cusp catastrophe for the case of one-dimensional branching of the buckling-allowed tensegrity model, and an elliptic umbilic singularity for compound branching of a rigid-bar model. It is pointed out that singularity studies with constraints demand a quite different mathematical approach than those without constraints. (C) 2009 Elsevier Ltd. All rights reserved. |
UT |
WOS:000274842500003 |
SN |
0020-7683 |
DI |
10.1016/j.ijsolstr.2009.11.010 |
PT |
J |
TI |
Form-finding of nonregular tensegrities using a genetic algorithm |
AU |
Xu, X |
SO |
MECHANICS RESEARCH COMMUNICATIONS |
VL |
37 |
IS |
1 |
BP |
85 |
EP |
91 |
PY |
2010 |
TC |
0 |
AB |
In this paper, the form-finding problem of nonregular tensegrities was converted into a constrained optimization problem A genetic algorithm was used to solve this problem Two cases of form-finding were considered In the first case, the number of members, the rest lengths of members, the elastic moduli of members and the connectivity of members were given, and the only variables are the initial locations of nodes In the second case, the elastic moduli of members were also treated as variables besides the initial locations of nodes Typical examples were carried out to verify the proposed method (C) 2009 Elsevier Ltd All rights reserved |
UT |
WOS:000275352000016 |
SN |
0093-6413 |
DI |
10.1016/j.mechrescom.2009.09.003 |
PT |
J |
TI |
Design of tensegrity structures using parametric analysis and stochastic search |
AU |
Rhode-Barbarigos, L |
SO |
ENGINEERING WITH COMPUTERS |
VL |
26 |
IS |
2 |
BP |
193 |
EP |
203 |
PY |
2010 |
TC |
0 |
AB |
Tensegrity structures are lightweight structures composed of cables in tension and struts in compression. Since tensegrity systems exhibit geometrically nonlinear behavior, finding optimal structural designs is difficult. This paper focuses on the use of stochastic search for the design of tensegrity systems. A pedestrian bridge made of square hollow-rope tensegrity ring modules is studied. Two design methods are compared in this paper. Both methods aim to find the minimal cost solution. The first method approximates current practice in design offices. More specifically, parametric analysis that is similar to a gradient-based optimization is used to identify good designs. Parametric studies are executed for each system parameter in order to identify its influence on response. The second method uses a stochastic search strategy called probabilistic global search Lausanne. Both methods provide feasible configurations that meet civil engineering criteria of safety and serviceability. Parametric studies also help in defining search parameters such as appropriate penalty costs to enforce constraints while optimizing using stochastic search. Traditional design methods are useful to gain an understanding of structural behavior. However, due to the many local minima in the solution space, stochastic search strategies find better solutions than parametric studies. |
UT |
WOS:000275953000010 |
SN |
0177-0667 |
DI |
10.1007/s00366-009-0154-1 |
PT |
J |
TI |
Dynamic behavior and vibration control of a tensegrity structure |
AU |
Ali, NBH |
SO |
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES |
VL |
47 |
IS |
9 |
BP |
1285 |
EP |
1296 |
PY |
2010 |
TC |
0 |
AB |
Tensegrities are lightweight space reticulated structures composed of cables and struts. Stability is provided by the self-stress state between tensioned and compressed elements. Tensegrity systems have in general low structural damping, leading to challenges with respect to dynamic loading. This paper describes dynamic behavior and vibration control of a full-scale active tensegrity structure. Laboratory testing and numerical simulations confirmed that control of the self-stress influences the dynamic behavior. A multi-objective vibration control strategy is proposed. Vibration control is carried out by modifying the self-stress level of the structure through small movement of active struts in order to shift the natural frequencies away from excitation. The PGSL stochastic search algorithm successfully identifies good control commands enabling reduction of structural response to acceptable levels at minimum control cost. (C) 2010 Elsevier Ltd. All rights reserved. |
UT |
WOS:000276127200015 |
SN |
0020-7683 |
DI |
10.1016/j.ijsolstr.2010.01.012 |
PT |
J |
TI |
Designing tensegrity modules for pedestrian bridges |
AU |
Rhode-Barbarigos, L |
SO |
ENGINEERING STRUCTURES |
VL |
32 |
IS |
4 |
BP |
1158 |
EP |
1167 |
PY |
2010 |
TC |
0 |
AB |
Tensegrity systems are spatial structures composed of tensile and compression components in a self-equilibrated state of prestress The tensegrity concept has already been studied by researchers in various fields over the past decades. A family of tensegrity modules that can offer promising solutions for civil engineering applications such as tensegrity domes, towers and bridges is analyzed. Research into tensegrity systems has resulted in reliable techniques for form finding and structural analysis. However. the tensegrity concept is not yet part of mainstream structural design. This paper presents a design study of a tensegrity-based pedestrian bridge The structural performance of the bridge using three tensegrity modules is evaluated through parametric studies Design requirements for pedestrian bridges and results of parametric studies are used to define a design procedure that optimizes section sizes for this type of structure A structural efficiency indicator is proposed and used to compare proposals for feasible bridge configurations Design results illustrate that the hollow-rope tensegrity bridge can efficiently meet typical design criteria (C) 2010 Elsevier Ltd. All rights reserved |
UT |
WOS:000276382200024 |
SN |
0141-0296 |
DI |
10.1016/j.engstruct.2009.12.042 |
PT |
J |
TI |
The simple model of cell prestress maintained by cell incompressibility |
AU |
Vychytil, J |
CT |
1st IMACS International Conference on Computational Biomechanics and Biology (ICCBB 2007) |
CY |
SEP 10-14, 2007 |
CL |
Univ W Bohemia, Pilsen, CZECH REPUBLIC |
SO |
MATHEMATICS AND COMPUTERS IN SIMULATION |
VL |
80 |
IS |
6 |
BP |
1337 |
EP |
1344 |
PY |
2010 |
TC |
0 |
AB |
Living cells are reinforced by polymer fibers (the so-called cytoskeleton) which ale responsible for their mechanical behaviour There are many evidences that these fibres are prestressed without an external load To include this prestress into mechanical models of living tissues is not an easy task We propose an approach in which the intracellular prestress is maintained by the incompressibility of cells. A simple illustrative structure is studied in older to determine the dependence of stiffness on the level of prestress Some macroscopic models of lime tissues with prestressed cells are formulated The results show a clear dependence of the macroscopic mechanical response on the level of prestress at microscale. The model exhibits some features of lime cells (prestress-induced stiffening. strain hardening) (C) 2009 IMACS. Published by Elsevier B.V. All rights reserved |
UT |
WOS:000276380400029 |
SN |
0378-4754 |
DI |
10.1016/j.matcom.2009.02.005 |
PT |
J |
TI |
Intermediate filament-deficient cells are mechanically softer at large deformation: A multi-scale simulation study |
AU |
Bertaud, J |
SO |
ACTA BIOMATERIALIA |
VL |
6 |
IS |
7 |
BP |
2457 |
EP |
2466 |
PY |
2010 |
TC |
0 |
AB |
The cell's cytoskeleton, providing cells with structure and shape, consists of different structural proteins, including microtubules, actin microfilaments and intermediate filaments. It has been suggested that intermediate filaments play a crucial role in providing mechanical stability to cells. By utilizing a simple coarse-grained computational model of the intermediate filament network in eukaryotic cells, we show here that intermediate filaments play a significant role in the cell mechanical behavior at large deformation, and reveal mechanistic insight into cell deformation under varying intermediate filament densities. We find that intermediate filament-deficient cells display an altered mechanical behavior, featuring a softer mechanical response at large deformation while the mechanical properties remain largely unchanged under small deformation. We compare the results with experimental studies in vimentin-deficient cells, showing good qualitative agreement. Our results suggest that intermediate filaments contribute to cell stiffness and deformation at large deformation, and thus play a significant role in maintaining cell structural integrity in response to applied stress and strain, in agreement with earlier hypotheses. The simulation results also suggest that changes in the filament density result in profound alterations of the deformation state of the cell nucleus, leading to greater stretch in the direction of loading and greater contraction in the orthogonal direction as the intermediate filament density is increased. Our model opens the door to future studies to investigate disease states, the effects of amino acid mutations and how structural changes at different levels in the cell's structural makeup influence biomechanical properties. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
UT |
WOS:000278868000010 |
SN |
1742-7061 |
DI |
10.1016/j.actbio.2010.01.028 |
PT |
J |
TI |
Initial self-stress design of tensegrity grid structures |
AU |
Tran, HC |
SO |
COMPUTERS & STRUCTURES |
VL |
88 |
IS |
9-10 |
BP |
558 |
EP |
566 |
PY |
2010 |
TC |
0 |
AB |
A numerical method is presented for initial self-stress design of tensegrity grid structures, which is defined as the linear combination of the coefficients of independent self-stress modes. A discussion on proper division of the number of member groups for the purpose of existence of a single integral feasible self-stress mode has been explicitly given. The unilateral properties of the stresses in cables and struts are taken into account. Evaluation of the stability for the structure is also considered. Three numerical examples are presented to demonstrate the efficiency and robustness in searching initial feasible self-stress mode for tensegrity grid structures. (C) 2010 Elsevier Ltd. All rights reserved. |
UT |
WOS:000277794200005 |
SN |
0045-7949 |
DI |
10.1016/j.compstruc.2010.01.011 |
PT |
J |
TI |
Tensegrity frameworks in one-dimensional space |
AU |
Recski, A |
CT |
Workshop on Rigidity and Flexibility |
CY |
2006 |
CL |
Erwin Schrodinger Int Inst Math Phys, Vienna, AUSTRIA |
SO |
EUROPEAN JOURNAL OF COMBINATORICS |
VL |
31 |
IS |
4 |
BP |
1072 |
EP |
1079 |
PY |
2010 |
TC |
0 |
AB |
The edge set of a graph G is partitioned into two subsets E-C boolean OR E-S. A tensegrity framework with underlying graph G and with cables for E-C and struts for E-S is proved to be rigidly embeddable into a one-dimensional line if and only if G is 2-edge-connected and every 2-vertex-connected component of G intersects both E-C and E-S. Polynomial algorithms are given for finding an embedding of such graphs and for checking the rigidity of a given one-dimensional embedding. (C) 2009 Elsevier Ltd. All rights reserved. |
UT |
WOS:000277741700005 |
SN |
0195-6698 |
DI |
10.1016/j.ejc.2009.09.008 |
PT |
J |
TI |
Real-time self-collision detection algorithms for tensegrity systems |
AU |
Cefalo, M |
SO |
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES |
VL |
47 |
IS |
13 |
BP |
1711 |
EP |
1722 |
PY |
2010 |
TC |
0 |
AB |
This work addresses the problem of real-time self-collision detection for a movable tensegrity structure We show that it can be tackled as the collision detection between two generic cylinders moving in R-3. It is a simplified version of the more general problem of dynamic collision detection between two general shaped rigid bodies in the space Two algorithms are proposed. The first presented approach is based on the exact value of the distance between two cylinders, the second is based on a new theorem which allows to estimate the exact distance for a given maximum desired error. In some circumstances, the second approach can be preferred because faster (C) 2010 Elsevier Ltd. All rights reserved. |
UT |
WOS:000277965700006 |
SN |
0020-7683 |
DI |
10.1016/j.ijsolstr.2010.03.010 |
PT |
J |
TI |
Advanced form-finding for cable-strut structures |
AU |
Tran, HC |
SO |
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES |
VL |
47 |
IS |
14-15 |
BP |
1785 |
EP |
1794 |
PY |
2010 |
TC |
1 |
AB |
A numerical method is presented for form-finding of cable-strut structures. The topology and the types of members are the only information that is required in this form-finding process. Dummy members are used to transform the cable-strut structure with supports into self-stressed system without supports. The requirement on rank deficiencies of the force density and equilibrium matrices for the purpose of obtaining a non-degenerate d-dimensional self-stressed structure has been explicitly discussed. The spectral decomposition of the force density matrix and the singular value decomposition of the equilibrium matrix are performed iteratively to find the feasible sets of nodal coordinates and force densities which satisfy the minimum required rank deficiencies of the force density and equilibrium matrices, respectively. Based on numerical examples it is found that the proposed method is very efficient, robust and versatile in searching self-equilibrium configurations of cable-strut structures. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved. |
UT |
WOS:000278280900004 |
SN |
0020-7683 |
DI |
10.1016/j.ijsolstr.2010.03.008 |
PT |
J |
TI |
A Monte Carlo form-finding method for large scale regular and irregular tensegrity structures |
AU |
Li, Y |
SO |
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES |
VL |
47 |
IS |
14-15 |
BP |
1888 |
EP |
1898 |
PY |
2010 |
TC |
1 |
AB |
We propose a Monte Carlo form-finding method that employs a stochastic procedure to determine equilibrium configurations of a tensegrity structure. This method does not involve complicated matrix operations or symmetry analysis, works for arbitrary initial configurations, and can handle large scale regular or irregular tensegrity structures with or without material/geometrical constraints. (C) 2010 Elsevier Ltd. All rights reserved. |
UT |
WOS:000278280900014 |
SN |
0020-7683 |
DI |
10.1016/j.ijsolstr.2010.03.026 |
PT |
J |
TI |
DETERMINATION OF THE ANALYTICAL WORKSPACE BOUNDARIES OF A NOVEL 2-DOF PLANAR TENSEGRITY MECHANISM |
AU |
Arsenault, M |
SO |
TRANSACTIONS OF THE CANADIAN SOCIETY FOR MECHANICAL ENGINEERING |
VL |
34 |
IS |
1 |
BP |
75 |
EP |
91 |
PY |
2010 |
TC |
0 |
AB |
Tensegrity mechanisms are slowly emerging as potential alternatives to more conventional mechanisms for certain types of applications where a reduced inertia of the mobile parts and a high payload to weight ratio are sought. With this in mind, a two-degree-of-freedom planar tensegrity mechanism is developed using a simple actuation strategy to keep the mechanism in self-stressed configurations. Solutions to the mechanism's direct and inverse kinematic problems are first developed and are then used to determine analytical expressions for its workspace boundaries. |
UT |
WOS:000278494700005 |
SN |
0315-8977 |
PT |
J |
TI |
Inelastic mechanics of sticky biopolymer networks |
AU |
Wolff, L |
SO |
NEW JOURNAL OF PHYSICS |
VL |
12 |
PY |
2010 |
TC |
0 |
AB |
We propose a physical model for the nonlinear inelastic mechanics of sticky biopolymer networks with potential applications to inelastic cell mechanics. It consists of a minimal extension of the glassy wormlike chain (GWLC) model, which has recently been highly successful as a quantitative mathematical description of the viscoelastic properties of biopolymer networks and cells. To extend its scope to nonequilibrium situations, where the thermodynamic state variables may evolve dynamically, the GWLC is furnished with an explicit representation of the kinetics of breaking and reforming sticky bonds. In spite of its simplicity, the model exhibits many experimentally established nontrivial features such as power-law rheology, stress stiffening, fluidization and cyclic softening effects. |
UT |
WOS:000278632800004 |
SN |
1367-2630 |
DI |
10.1088/1367-2630/12/5/053024 |
PT |
J |
TI |
Self-assembly of three-dimensional prestressed tensegrity structures from DNA |
AU |
Liedl, T |
SO |
NATURE NANOTECHNOLOGY |
VL |
5 |
IS |
7 |
BP |
520 |
EP |
524 |
PY |
2010 |
TC |
2 |
AB |
Tensegrity, or tensional integrity, is a property of a structure indicating a reliance on a balance between components that are either in pure compression or pure tension for stability(1,2). Tensegrity structures exhibit extremely high strength-to-weight ratios and great resilience, and are therefore widely used in engineering, robotics and architecture(3,4). Here, we report nanoscale, prestressed, three-dimensional tensegrity structures in which rigid bundles of DNA double helices resist compressive forces exerted by segments of single-stranded DNA that act as tension-bearing cables. Our DNA tensegrity structures can self-assemble against forces up to 14 pN, which is twice the stall force of powerful molecular motors such as kinesin or myosin(5,6). The forces generated by this molecular prestressing mechanism can be used to bend the DNA bundles or to actuate the entire structure through enzymatic cleavage at specific sites. In addition to being building blocks for nanostructures, tensile structural elements made of single-stranded DNA could be used to study molecular forces, cellular mechano-transduction and other fundamental biological processes. |
UT |
WOS:000280529800015 |
SN |
1748-3387 |
DI |
10.1038/NNANO.2010.107 |
PT |
J |
TI |
Control of a Seismically Excited Benchmark Building Using Linear Matrix Inequality-Based Semiactive Nonlinear Fuzzy Control |
AU |
Kim, Y |
SO |
JOURNAL OF STRUCTURAL ENGINEERING-ASCE |
VL |
136 |
IS |
8 |
BP |
1023 |
EP |
1031 |
PY |
2010 |
TC |
0 |
AB |
This paper investigates the behavior of a seismically excited benchmark building employing magnetorheological dampers operated by a model-based fuzzy logic controller (MBFLC) formulated in terms of linear matrix inequalities (LMIs). The MBFLC is designed in a systematic way, while the traditional model-free fuzzy logic controller is designed via trial and error by experienced investigators. It is demonstrated from comparison of the uncontrolled and semiactive controlled responses that the proposed LMI-based MBFLC is effective in vibration reduction of a benchmark building under various earthquake loading conditions. |
UT |
WOS:000279991700011 |
SN |
0733-9445 |
DI |
10.1061/(ASCE)ST.1943-541X.0000192 |
PT |
J |
TI |
Design methods of rhombic tensegrity structures |
AU |
Feng, XQ |
SO |
ACTA MECHANICA SINICA |
VL |
26 |
IS |
4 |
BP |
559 |
EP |
565 |
PY |
2010 |
TC |
0 |
AB |
As a special type of novel flexible structures, tensegrity holds promise for many potential applications in such fields as materials science, biomechanics, civil and aerospace engineering. Rhombic systems are an important class of tensegrity structures, in which each bar constitutes the longest diagonal of a rhombus of four strings. In this paper, we address the design methods of rhombic structures based on the idea that many tensegrity structures can be constructed by assembling one-bar elementary cells. By analyzing the properties of rhombic cells, we first develop two novel schemes, namely, direct enumeration scheme and cell-substitution scheme. In addition, a facile and efficient method is presented to integrate several rhombic systems into a larger tensegrity structure. To illustrate the applications of these methods, some novel rhombic tensegrity structures are constructed. |
UT |
WOS:000280373000006 |
SN |
0567-7718 |
DI |
10.1007/s10409-010-0351-6 |
PT |
J |
TI |
Proportional damping approximation using the energy gain and simultaneous perturbation stochastic approximation |
AU |
Sultan, C |
SO |
MECHANICAL SYSTEMS AND SIGNAL PROCESSING |
VL |
24 |
IS |
7 |
BP |
2210 |
EP |
2224 |
PY |
2010 |
TC |
0 |
AB |
The design of vector second-order linear systems for accurate proportional damping approximation is addressed. For this purpose an error system is defined using the difference between the generalized coordinates of the non-proportionally damped system and its proportionally damped approximation in modal space. The accuracy of the approximation is characterized using the energy gain of the error system and the design problem is formulated as selecting parameters of the non-proportionally damped system to ensure that this gain is sufficiently small. An efficient algorithm that combines linear matrix inequalities and simultaneous perturbation stochastic approximation is developed to solve the problem and examples of its application to tensegrity structures design are presented. (C) 2010 Elsevier Ltd. All rights reserved. |
UT |
WOS:000280940200021 |
SN |
0888-3270 |
DI |
10.1016/j.ymssp.2010.02.013 |
PT |
J |
TI |
Self-stress design of tensegrity grid structures with exostresses |
AU |
Tran, HC |
SO |
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES |
VL |
47 |
IS |
20 |
BP |
2660 |
EP |
2671 |
PY |
2010 |
TC |
0 |
AB |
A numerical method is presented for initial self-stress design of tensegrity grid structures with exostresses. which is defined as a linear combination of the coefficients of independent self-stress modes. A discussion on proper division of the number of member groups for the purpose of existence of a single integral feasible self-stress mode has been explicitly given. Dummy elements to transform the tensegrity grid structure with statically indeterminate supports into self-stressed pin-jointed system without supports are employed. The unilateral properties of the stresses in cables and struts are taken into account. Evaluation of the stability for the structure is also considered. Several numerical examples are presented to demonstrate the efficiency and robustness in searching initial single integral feasible self-stress mode for tensegrity grid structures. (C) 2010 Elsevier Ltd. All rights reserved. |
UT |
WOS:000281175800004 |
SN |
0020-7683 |
DI |
10.1016/j.ijsolstr.2010.05.020 |
PT |
J |
TI |
High magnetic gradient environment causes alterations of cytoskeleton and cytoskeleton-associated genes in human osteoblasts cultured in vitro |
AU |
Qian, AR |
SO |
ADVANCES IN SPACE RESEARCH |
VL |
46 |
IS |
6 |
BP |
687 |
EP |
700 |
PY |
2010 |
TC |
0 |
AB |
The effects of a high magnetic gradient environment (HMGE) on the cytoskeletal architecture and genes associated with the cytoskeleton in osteoblasts (MC3T3-EI and MG-63 cells) were investigated using confocal microscopy, real-time polymerase chain reaction (PCR) and atomic force microscopy (AFM). The findings showed that, under diamagnetic levitation conditions, the architecture and average height of the cytoskeleton and surface roughness in osteoblasts were dramatically altered. HMGE affects cytoskeleton arrangement and cytoskeleton-associated gene expression. (C) 2010 COSPAR. Published by Elsevier Ltd. All rights reserved. |
UT |
WOS:000281296600002 |
SN |
0273-1177 |
DI |
10.1016/j.asr.2010.04.012 |
