In-core heat distribution control for adaptive damping and stiffness tuning of composite structures

Abstract

In this work, a smart composite structure with damping and stiffness control ability is proposed. The multilayered arrangement has a shape memory core, whose damping and stiffness are tuned by temperature control. The structure is divided in several zones, each of them can be heated in real time using temperature regulation to reach the expected mechanical properties provided by the strong temperature and frequency dependency of the stiffness and loss factor of the viscoelastic core. The heat flux, which is used to tune the mechanical properties, is provided by copper tracks printed on an electronic board used as skin of the sandwich. The paper presents a model-based design process, including thermal and mechanical simulations, providing the gradient temperature fields which are required to obtain a specific damping and stiffness. Experimental tests are finally presented, considering three configurations with various temperature sets corresponding to three different compromises between static stiffness and dynamic damping.

Zero reflections by a 1D Acoustic Black Hole termination using thermally controlled damping

“…To avoid a truncation, the tip is extended by a uniform plateau of thickness ℎ from to the end of the beam. This ABH is enhanced (eABH) by partially covering it with a layer of SMP and an integrated heating device [25,26].…”

“…In the same direction, the ABH effect has been mimicked [23] or enhanced [24] by means of functionally graded materials. The work presented in this article takes advantage of distributed heaters able to locally control the damping [25], so that loss factors gradients can be obtained. These gradients, which can be tuned in real time, are powerful tools that can be used to follow the poles and zeros of the reflection coefficient in the complex frequency plane.…”

Control of bending wave reflection at beam terminations by thermally tunable subwavelength resonators

“…This particular temperature is localised in the transition state where the material changes from a glassy state to a rubbery state. We use tBA/PEGDMA which has been characterized in previous studies [16] and for which it is possible to precisely adjust the damping of the system by thermal control [17].…”

Magnetically induced friction damping based on magnetoactive elastomers — A proof of concept

“…The viscoelastic damping is independent from the vibration magnitude and is therefore classified as a linear mechanism. However, the main drawback of viscoelastic materials is their sensitivity to temperature and frequency variations [1]. Until today, magnetoactive elastomers have been studied exclusively in the context of the adaptive vibration control by external magnetic fields [2,3,4,5,6,7].…”