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1

Performance analysis of serpentine springs compliant to out-of-plane oscillation

Duong Nguyen Van, Chien Nguyen Quoc, Hieu Dang Van, Hoang Chu Manh

Journal of Theoretical and Applied Mechanics

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2022

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Vol. 60 nr 1

91--101

EN

The performance of two serpentine type springs is comparatively investigated. The first type is composed of straight beams and the second one is composed of circular arcs. Based on comparing calculation results and simulation data, the crab-leg spring model is appropriate for evaluating the stiffness of springs. To obtain the operation mode to be the first mode, the number of turns and the opening angle of springs should be increased. The performance of springs is evaluated via analysis of mode coupling. This study is useful for choosing an appropriate serpentine spring and the stiffness calculation model for applications in microelectroemchanical sensors and actuators.

2

Design and performance analysis of a mechanically coupled spring compliant to out-of-plane oscillation

Nguyen Duong Van, Nguyen Chien Quoc, Dang Hieu Van, Chu Hoang Manh

Archive of Mechanical Engineering

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2022

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LXIX, nr 4

629--643

EN

In this paper, a spring system symmetrically arranged around a circular plate compliant to out-of-plane oscillation is proposed. The spring system consists of single serpentine springs mutually coupled in a plane. Three theoretical mechanical models for evaluating the stiffness of the spring system are built, which are based on the flexural beam, Sigitta, and serpentine spring theories and equivalent mechanical spring structure models. The theoretically calculated results are in good agreement with numerical solutions using the finite element method, with errors less than 10% in the appropriate dimension ranges of the spring. Compared to similar spring structures without mechanical coupling, the proposed mechanically coupled spring shows advantage in suppressing the mode coupling.

3

Time Domain Simulation of Optical MIMO Channels

Köhnke H., Bartmann P., Ahrens A., Lochmann S.

Przegląd Elektrotechniczny

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2015

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R. 91, nr 4

56--59

EN

In recent years the interest in optical multiple-input multiple-output (MIMO) transmission has increased significantly. Focus of this work is the development of a time domain model of optical MIMO channels using modal diversity. Next to modal and chromatic dispersion, modal crosstalk caused by mode combiner, splitter, splices and also modal coupling within the transmitting fiber can be taken into account. The simulated MIMO impulse responses are validated by practical measurements. The channel measurements confirm the accuracy of the proposed time domain model.

PL

W artykule omawia się optyczny system transmisji typu MIMO (multiple input – multiple output). Zaproponowano model czasowy optycznego kanału MIMO. Wzięto pod uwagę modalną i chromatyczną dyspersję , modalny crosstalk (przesłuch) oraz modalne sprzężenie włókna optycznego.

4

Influence of modal filtering on the bandwidth of multimode optical fibers

Siuzdak J., Stepniak G.

Optica Applicata

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2007

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Vol. 37, nr 1-2

31-39

EN

The multimode (MM) optical fiber maximum operational range is defined by the fiber bandwidth (related to the intermodal dispersion) rather than by the fiber attenuation. The relationship between the modal bandwidth of the fiber, the launching condition and mode coupling is fairly complicated. There is presented a theoretical study on the modal bandwidth of the multimode fiber. The theory is based on a numerical solution of the coupled mode diffusion equation that allows the bandwidth of the MM optical fiber to be calculated. It is shown that appropriate modal filtering at the receiver side of the fiber link increases the link bandwidth.