This paper concerns the manufacturing processes of thermoplastic structures including piezoceramic patches (PZT). The objective of the study reported here was to find a trade-off between the manufacturing conditions and the thermal endurance of the PZT patches. We studied the influence of high temperatures on the PZT efficiency during manufacturing. Two processes were considered: injection molding and thermoforming. The studied object consists of a polypropylene plate containing a PZT patch integrated at different positions. On the one hand, we simulated with ANSYS the thermal transient effects to study the PZT cooling according to the time of its exposure to heat for different fabrication cases and with different manufacturing processes. On the other hand, the loss in PZT generated voltage according to the temperature increment was measured by thermo-mechanical experiences using a dynamical-mechanical analysis machine (DMA) connected to an acquisition chain.

The frame of the paper is the integration ofPZT actuators and sensors within thermoplas tic mechanical structures. The objective of the work reported here was to select the appropriate thermoplastic materials for the smart thermoplastic manufacturing. In order to reach this objective, a comparative study was realized between different thermoplastic materials taking into consideration the PZT patch maximum temperature, the overheat time o f the PZT patch during injection process, and the PZT loss in piezoelectric properties due to its thermal fragility.

In order to know the origin of the noise generation when an impinging jet hit a specific geometry, an experimental setup was used allowing the generation of the flow and the adjustments of its parameters (such as Reynolds number, confinement, alignment, etc…). The vortex dynamics in case of a high acoustic level for two different Reynolds numbers Re = 5684 and Re = 6214 are considered here. Indeed, many configurations allow self-sustaining sound loop to take place in confined spaces between the nozzle and the impinged surface. This feedback loop optimizes the energy transfer between the aerodynamic field and the acoustic field and creates a source of noise that can become very noisy. Thus, to control these phenomena, it is necessary to understand the aero-acoustic coupling in such configurations. As a result, we measured the 2C kinematic instantaneous fields (vx, vy) of the flow by the technique of Particle Image Velocimetry (PIV) with a sampling rate of 1 KHz and the acoustic field is obtained using a B&K Microphone. For the two considered Reynold numbers, we can distinguish two patterns for the vortices travelling from the nozzle toward the plate of impact.

The adaptable mechanical structures in the form of Shell have found large developments and use in many applications, especially in the field of smart structures where the piezoelectric components are used as actuators and sensors. Many functional constraints prevent the control of a structure by elements reported on the surfaces of the object. Thus, the piezoelectric components necessary for the control of the structures will be integrated into this, i.e., in material, even the material of the wall. Certain work describes the manner and the performances of structures by using composite materials with thermoset matrices as structural support and piezoelectric components as the actuator or sensor elements. The current difficulties in recycling the thermoset materials are hindering the industrial development of such structures. For this reason, we propose to use composites with a thermoplastic matrix. Unfortunately, the current processes of achieving models in smart thermoplastic structures are not directly exploitable for the integration of components such as the piezoelectric actuators and sensors which are fragile and sensitive to temperature.This work evaluates the sizes typically reached in the process transformations of such composites with a thermoplastic matrix in order to be able to establish the behavior models for the realized structures. A thermo-mechanic testing method using dynamic mechanical analysis (DMA) is also proposed.