The reduction of actuator's resonant amplitudes with damping material

Based on the bi-directional evolutionary structural optimization (BESO), the method of determining the adhesion position of the damping material is proposed in this paper, which is applicable to the vibration damping of ship plate. In this method, the needed amount of damping material is taken as the constraint condition, and the maximization of one natural vibration frequency of the structure is taken as the target function. A thin plate structure with both ends constraints has been taken as an example to get the best topology structure of its adhesion damper by taking the BESO method. The result of optimization shows that it still meets the damping requirements when the needed amount of damping material decreases by about 50% of the original amount. The reasonable result demonstrates the effectiveness and engineering value of the method.

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Analysis of Modal Parameters of Adhesively Bonded Double-Strap Joints by the Modal Strain Energy Method

14th Biennial Conference on Mechanical Vibration and Noise: Vibration Isolation, Acoustics, and Damping in Mechanical Systems ◽

10.1115/detc1993-0242 ◽

1993 ◽

Author(s):

Mohan D. Rao ◽

Krishna M. Gorrepati

Keyword(s):

Strain Energy ◽

Natural Frequencies ◽

Structural Parameters ◽

Flexural Vibration ◽

Mode Shapes ◽

Modal Parameters ◽

Adhesively Bonded ◽

Modal Strain Energy ◽

Joint System ◽

Damping Material

Abstract This paper presents the analysis of modal parameters (natural frequencies, damping ratios and mode shapes) of a simply supported beam with adhesively bonded double-strap joint by the finite-element based Modal Strain Energy (MSE) method using ANSYS 4.4A software. The results obtained by the MSE method are compared with closed form analytical solutions previously obtained by the first author for flexural vibration of the same system. Good agreement has been obtained between the two methods for both the natural frequencies and system loss factors. The effects of structural parameters and material properties of the adhesive on the modal properties of the joint system are also studied which are useful in the design of the joint system for passive vibration and noise control. In order to evaluate the MSE and analytical results, some experiments were conducted using aluminum double-strap joint with 3M ISD112 damping material. The experimental results agreed well with both analytical and MSE results indicating the validity of both analytical and MSE methods. Finally, a comparative study has been conducted using various commercially available damping materials to evaluate their relative merits for use in the design of these joints.

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A strengthening approach for damping property and shape memory property of acrylic rubber/polylactide blends

Journal of Elastomers & Plastics ◽

10.1177/0095244318808032 ◽

2018 ◽

Vol 51 (7-8) ◽

pp. 626-643

Author(s):

Chengliang Li ◽

Xingxing Ji ◽

Yang Lyu ◽

Xinyan Shi

Keyword(s):

Shape Memory ◽

Loss Factor ◽

Phenol Formaldehyde ◽

Mechanical Analysis ◽

Damping Properties ◽

Shape Memory Property ◽

Memory Property ◽

Damping Material ◽

Shape Memory Properties ◽

Shape Memory Effects

In this work, a damping material was successfully prepared by blending acrylic rubber (ACM) and polylactide (PLA) with sulfur and soap salt as the curing agents. A phenol-formaldehyde (PF) resin was used as a modifier. The effects of PF on the mechanical properties, damping properties, compatibility and shape memory properties of the blends were studied. The compatibility and damping properties were characterized by dynamic mechanical analysis, Fourier transform infrared spectroscope and microstructure analysis. The shape memory properties were examined by thermal mechanical analyser. The results revealed that the tensile strength of the blends was decreased and the toughness was increased with the increase of PF loadings. The introduction of PF improved the compatibility between PLA and ACM, which was deduced from the fact that the glass transition temperature of ACM was increased and the two loss factor peaks became closer. It was also found that the loss factor peak became higher and the effective damping temperature range became wider due to the formation of hydrogen bonding, implying that the damping properties of ACM/PLA blends were significantly improved. The ACM/PLA blends exhibited good dual-shape memory effect and its shape recovery ratio was increased by introduction of PF and raising the trigger temperature. The blends also exhibited good triple-shape memory property, which was dramatically improved by the introduction of PF. The mechanisms for the enhanced shape memory effects were then analysed.

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