Finite element modelling the forming of components for portable electronic devices
type: CreativeWork
description: Due to the growing popularity of portable electronic devices, a drive for their continuous development and improvement is ever-present. Micro-speaker components are no different, with new materials and configurations proposed to fulfil these increasing performance requirements. The favourable inherent mechanical properties possessed by poly(ether-ether-ketone) (PEEK) suggest its inclusion as a critical component within a global material assembly for the next evolution in micro-speaker component membranes. The industrial practice of thermoforming is widely used for the large-scale manufacture of lightweight, thin-walled polymeric parts with the advantage of producing repeatable, complex products, paired with relatively cheap production costs. Desire to accurately predict the deformation behaviour throughout the forming process has led to the development of mathematical models representative of material behaviour, with the ultimate aim of embedding these relationships into forming simulations enabling process and product optimization. Herein lies a methodology to effectively characterise and model the constitutive thermomechanical response of thin PEEK films when subject to loading histories characteristic to those experienced during the thermoforming process. Following design and manufacture of a custom rig chosen to replicate the multi-axial state of stress induced associate with the forming process, initial load controlled bulge testing experiments revealed non-linear strain paths in principal directions yielding average and maximum strain rate ranges of 2.5–5 s-1 and 5–18 s-1 respectively, across the forming temperature range of 130–155 ⁰C. Extensive in-plane biaxial testing used to uncover the specific contributions of external variables on the observed stress-strain behaviour highlighted the anisotropic non-linear viscoelastic behaviour of the films – with strong dependence of the yield and strain hardening behaviour on the temperature and strain history at cond…
abstract: Due to the growing popularity of portable electronic devices, a drive for their continuous development and improvement is ever-present. Micro-speaker components are no different, with new materials and configurations proposed to fulfil these increasing performance requirements. The favourable inherent mechanical properties possessed by poly(ether-ether-ketone) (PEEK) suggest its inclusion as a critical component within a global material assembly for the next evolution in micro-speaker component membranes. The industrial practice of thermoforming is widely used for the large-scale manufacture of lightweight, thin-walled polymeric parts with the advantage of producing repeatable, complex products, paired with relatively cheap production costs. Desire to accurately predict the deformation behaviour throughout the forming process has led to the development of mathematical models representative of material behaviour, with the ultimate aim of embedding these relationships into forming simulations enabling process and product optimization. Herein lies a methodology to effectively characterise and model the constitutive thermomechanical response of thin PEEK films when subject to loading histories characteristic to those experienced during the thermoforming process. Following design and manufacture of a custom rig chosen to replicate the multi-axial state of stress induced associate with the forming process, initial load controlled bulge testing experiments revealed non-linear strain paths in principal directions yielding average and maximum strain rate ranges of 2.5–5 s-1 and 5–18 s-1 respectively, across the forming temperature range of 130–155 ⁰C. Extensive in-plane biaxial testing used to uncover the specific contributions of external variables on the observed stress-strain behaviour highlighted the anisotropic non-linear viscoelastic behaviour of the films – with strong dependence of the yield and strain hardening behaviour on the temperature and strain history at cond…
author: Turner, Josh
language: eng
keywords: poly(ether-ether-ketone), thermoforming, constitutive modelling, biaxial stretching, finite element model, simulation
date published: 2021-7
date modified: 2026-07-24T03:55:38Z
provider: Queen's University Belfast
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Queen's University Belfast