This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.Piezoelectric energy harvester composite under dynamic bending with implementation to aircraft wingbox structureDepartment of Mechanical Engineering, The University of Sheffield, Sir Frederick Mappin Building, Mappin Street, S1 3JD Sheffield, United Kingdom AbstractIn this paper, an investigation on the energy harvesting exerted by the dynamic bending responses of a piezoelectric embedded wingbox is presented. An innovative hybrid mathematical/computational scheme is built to evaluate the energy harvested by a mechanical system. The governing voltage differential equations of the piezoelectric composite beam are coupled with the finite element method output. The scheme is able of evaluating various excitation forms including dynamic force and base excitation. Thus, it provides the capability to analyse a complicated structure with a more realistic loading scenario. Application to the simulation of a notional jet aircraft wingbox with a piezoelectric skin layer is shown in some detail. The results pointed out that the electrical power generated can be as much as 25.24 kW for a 14.5 m wingspan. The capabilities and robustness of the scheme are shown by comparison with results from the literature.

Summary This paper explores the influence of linear hysteretic damping on the performance of passive tuned‐inerter devices. An inerter is a device that produces a force proportional to the relative acceleration across its two terminals; devices incorporating inerters have received widespread attention in the earthquake engineering community, because they offer the ability to improve the seismic response of structures. However, the majority of this research has assumed that the damping components within the tuned‐inerter device exhibit viscous, rather than hysteretic, damping. This restriction imposes an essential question on how the hysteretic damping model will change the performance of the device compared with the viscous damping model. It is shown that the response of viscous and hysteretic inerter systems have significant differences in displacement amplitude due to the frequency dependency of the damping. Therefore, a new formulation for obtaining the optimum loss factor of the hysteretic damping in the inerter system is proposed. Next, the challenges associated with accurately predicting the time‐response of a hysteretically damped system are discussed. A numerical time‐integration method is extended to address these challenges, using a new formulation that has the benefit of being broadly applicable to multidegree‐of‐freedom hysteretic linear systems and nonstationary random signals. The results show that the earthquake responses from the hysteretic damping model can differ significantly from the ones obtained via the viscous model.

The multiphase composite with active structural fiber (ASF) has proven able to provide better optimization between actuating and load bearing capability compared to a pure piezoelectric material. In this paper, the multiphase composite application is further extended for energy harvesting purpose. The Double-Inclusion model combined with Mori-Tanaka method is implemented in a computational code to estimate the effective electro-elastic properties of the multiphase composite. The effective composite properties obtained via the present code are in good agreement with the analytical, experimental and finite element results. The multiphase composite with different composition is applied to a typical jet aircraft wingbox with 14.5 m halfspan. The energy harvesting evaluation by means of hybrid FEM/analytical piezoelectric energy harvester model is presented. A new procedure to investigate the trade-off between the aircraft weight, the fuel saving and the energy harvested is developed. The results pointed out that the equivalent fuel saved from the power generated by the wingbox is more than enough for 1 hour Auxiliary Power Unit (APU) operation.

In this paper, a novel iterative finite element method (FEM) for energy harvesting purpose is presented. The new iterative FEM is implemented to solve the dynamic problems of piezoelectric-based energy harvester in the frequency and time domains. The validation against other methods from the literature shows the robustness and capabilities of the iterative FEM. Implementation to a transport aircraft wingbox with 14.5 m half span and an embedded piezoelectric layer is shown in some details. The energy harvesting potential of the wingbox due to the cruise and the 1-cosine gust loads is investigated. In addition, for the first time, stress and failure analyses of the structure with an active energy harvesting layer are performed. The results pointed out that the wingbox is still in a safe condition even when it is subjected to a 30 m/s gust amplitude while harvesting 51 kW power.

Structural integrity assessment on cracked composites interaction with aeroelastic constraint by means of XFEM (2019) Composite Structures, 229, art. no. 111414, .