In this paper, a symmetrically coated damping structure for entangled metallic wire materials (EMWM) of pipelines was designed to reduce the vibration of high temperature (300 °C) pipeline. A series of energy dissipation tests were carried out on the symmetrically coated damping structure at 20–300 °C. Based on the energy dissipation test results, the hysteresis loop was drawn. The effects of temperature, vibration amplitude, frequency, and density of EMWM on the energy dissipation characteristics of coated damping structures were investigated. A nonlinear energy dissipation model of the symmetrically coated damping structure with temperature parameters was established through the accurate decomposition of the hysteresis loop. The parameters of the nonlinear model were identified by the least square method. The energy dissipation test results show that the symmetrically coated damping structure for EMWM of pipelines had excellent and stable damping properties, and the established model could well describe the changing law of the restoring force and displacement of the symmetrically coated damping structure with amplitude, frequency, density, and ambient temperature. It is possible to reduce the vibration of pipelines in a wider temperature range by replacing different metal wires.

To reduce the vibration of a ship’s high-temperature pipeline, a long coated damping structure (LCDS) with entangled metallic wire material (EMWM) is proposed in this paper. The structural analysis of the long coated damping structure for pipelines is carried out. The theoretical analysis indicates that increasing the thickness of the damping layer in a particular range can improve the vibration attenuation effect of an LCDS. Additionally, experimental verification confirms this analysis after an experimental system for pipelines. From the results, it is observed that increasing the thickness of the coated layer can effectively improve the damping property of LCDS to a certain extent. The change of the coated length and the temperature has little effect on the vibration attenuation effect of an LCDS, indicating that the LCDS can work well in a high-temperature environment.

This work presents the experimental characterization and improved model of multi-strand entangled metallic wire materials (MS-EMWMs). MS-EMWM is a novel damping material made of several strands of entangled wires using a modified manufacturing process. Six batches of specimens were fabricated and tested under quasi-static loading. Secant stiffness and loss factor were calculated to indicate the mechanical properties. The results showed that MS-EMWM has the characteristics of high damping energy dissipation compared to EMWM. A micro-multi-strand spiral spring model was proposed to predict the mechanical properties of MS-EMWM. The probability distribution of micro-spring pairs between wires was used to characterize the random combination of materials. According to the results, the improved model can effectively reflect the mechanical behavior of MS-EMWM. The mechanical properties of MS-EMWM were predicted by the coefficient matrix obtained by particle swarm optimization. Through the prediction and test results, the predicted results are acceptable.

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