### Abstract

Original language | English |
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Journal | Mechanical Systems and Signal Processing |

Early online date | 6 Apr 2016 |

DOIs | |

Publication status | E-pub ahead of print - 6 Apr 2016 |

### Fingerprint

### Keywords

- reconfiguration
- four-bar mechanism
- heteroclinic connections
- instability
- active control

### Cite this

*Mechanical Systems and Signal Processing*. https://doi.org/10.1016/j.ymssp.2016.03.024

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**Reconfiguration of a four-bar mechanism using phase space connections.** / Zhang, Jiaying; McInnes, Colin R.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Reconfiguration of a four-bar mechanism using phase space connections

AU - Zhang, Jiaying

AU - McInnes, Colin R.

PY - 2016/4/6

Y1 - 2016/4/6

N2 - Linkage mechanisms are perhaps the simplest mechanical structures in engineering, but they can exhibit significant nonlinearity which can in principle be exploited. In this paper a simple smart structure model is developed based on such nonlinearity to investigate the reconfiguration of a four-bar mechanism through phase space connections. The central idea is based on heteroclinic connections in the mechanism phase space between equal-energy unstable equilibria. It is proposed that transitions between such equal-energy unstable (but actively controlled) equilibria in principle require zero net energy input, compared to transitions between stable equilibria which require the input and then dissipation of energy. However, it can be difficult to obtain such heteroclinic connections numerically in complex dynamical systems, therefore an objective function approach is used to seek transitions between unstable equilibria which approximate true heteroclinic connections. The instability inherent in the model is therefore actively utilised to provide energy-efficient transitions between configurations of the mechanism. It will be shown that the four-bar mechanism then forms the basis for an elastic model of a smart buckling beam.

AB - Linkage mechanisms are perhaps the simplest mechanical structures in engineering, but they can exhibit significant nonlinearity which can in principle be exploited. In this paper a simple smart structure model is developed based on such nonlinearity to investigate the reconfiguration of a four-bar mechanism through phase space connections. The central idea is based on heteroclinic connections in the mechanism phase space between equal-energy unstable equilibria. It is proposed that transitions between such equal-energy unstable (but actively controlled) equilibria in principle require zero net energy input, compared to transitions between stable equilibria which require the input and then dissipation of energy. However, it can be difficult to obtain such heteroclinic connections numerically in complex dynamical systems, therefore an objective function approach is used to seek transitions between unstable equilibria which approximate true heteroclinic connections. The instability inherent in the model is therefore actively utilised to provide energy-efficient transitions between configurations of the mechanism. It will be shown that the four-bar mechanism then forms the basis for an elastic model of a smart buckling beam.

KW - reconfiguration

KW - four-bar mechanism

KW - heteroclinic connections

KW - instability

KW - active control

UR - http://www.sciencedirect.com/science/article/pii/S0888327016300383

U2 - 10.1016/j.ymssp.2016.03.024

DO - 10.1016/j.ymssp.2016.03.024

M3 - Article

JO - Mechanical Systems and Signal Processing

JF - Mechanical Systems and Signal Processing

SN - 0888-3270

ER -