PVDF Based Pressure Sensor for the Characterisation of the Mechanical Loading during High Explosive Hydro Forming of Metal Plates

Abstract

High explosive hydro forming (HEHF) is a suitable technique for large metal plate forming. Manufacturing stages of such a part requires an adapted design of explosive charge configurations to define the mechanical loading exerted on the part. This mechanical loading remains challenging to be experimentally determined but necessary for predictive numerical simulation in the design of parts to form. Providing that the actual mechanical impulse would allow the neglecting of the modelling of the detonation stage, this considerably increases the computational time. The present work proposes an experimental method for obtaining the exerted mechanical loading by HEHF on the part to form. It relies on the development of low-cost sensor based on a polyvinyliden fluorid (PVDF) gauge. In addition to it, an analytical approach based on shock physics is proposed for the sensor signal interpretation. The method considers the multi-layer aspect of the sensor and its intrusiveness with respect to waves propagation. Measurements were repeated to assess their relevance and the reproducibility by using steel and aluminium anvils in HEHF. Numerical modelling in 2D plane geometry of the experiments was performed with two commercial hydrocodes. The comparison of mechanical impulses shows an agreement in terms of chronology but a noticeable difference in terms of amplitude, explained by mesh size and numerical diffusion.

Current and future applications of PVDF-carbon nanomaterials in energy and sensing

“…The applications of the PVDF in sensing is not limited to the tactile ones. There are broadly utilized as nanosensors for humidity [343][344][345], force [344,[346][347][348], weather conditions [349], and pressure measurements [350][351][352]. In the case of the latter one, their significant role has been appreciated in the biomedicine [350,353,354], health monitoring [355][356][357][358], and acoustics [359][360][361].…”

Study on the Flow Behavior of 5052 Aluminum Alloy over a Wide Strain-Rate Range with a Constitutive Model Based on the Arrhenius Model Extension

“…The formability of aluminum sheets limits their application in complex-shaped products, such as automotive body parts. And scholars have proven that high-strain-rate forming techniques such as electromagnetic forming (EMF), explosive forming (EF), and electro-hydraulic forming (EHF) may improve the formability of sheet metal [1][2][3][4], and these techniques also have the advantages of simple die design, high workpiece accuracy, good surface quality, and especially strong plastic deformation ability, making high-strain-rate forming an ideal processing technology for materials with lower formability [5]. Thomas et al [6] proposed that the forming limit of 6063-T6 aluminum alloy under electromagnetic tube bulging is 2-3 times higher than that under quasi-static forming.…”

Metallic Materials and Their Applications in Aerospace and Advanced Technologies

“…Innovative industrial processes such as in the field of metal forming relying on high pulsed power with electromagnetic sources [15] and pulsed laser sources [16] are revolutionizing the manufacturing industry. In recent years, additive methods [17] and processing technologies such as electromagnetic and explosive welding [18,19] and stir welding [20] have also met incremental evolutions, allowing for the extension of forming limits and multimaterial assemblies. In any case, the reliability of resulting products and new materials needs to be characterized in terms of mechanical behavior.…”