Destructive and non-destructive mechanical characterisation of chocolate with different levels of porosity under various modes of deformation

Chocolate exhibits a complex material response under the varying mechanical loads present during oral processing. Mechanical properties such as Young’s modulus and fracture stress are linked to sensorial attributes such as hardness. Apart from this link with hardness perception, these mechanical properties are important input parameters towards developing a computational model to simulate the first bite. This study aims to determine the mechanical properties of chocolate with different levels of micro-aeration, 0–15%, under varying modes of deformation. Therefore, destructive mechanical experiments under tension, compression, and flexure loading are conducted to calculate the Young’s modulus, yield, and fracture stress of chocolate. The values of Young’s modulus are also confirmed by independent ultrasonic mechanical experiments. The results showed that differences up to 35% were observed amongst the Young’s modulus of chocolate for different mechanical experiments. This maximum difference was found to drop with increasing porosity and a negligible difference in the Young’s modulus measurements amongst the different mechanical experiments is observed for the 15% micro-aerated chocolate. This phenomenon is caused by micro-pores obstructing the microscopic inelastic movement occurring from the early stages of the material’s deformation. This work provides a deeper understanding of the mechanical behaviour of chocolate under different loading scenarios, which are relevant to the multiaxial loading during mastication, and the role of micro-aeration on the mechanical response of chocolate. This will further assist the food industry’s understanding of the design of chocolate products with controlled and/or improved sensory perception

The Conceptual LeanPPD Model

This paper is presenting the conceptual Lean Product and Process Development (LeanPPD) model which is a project funded by the EU-PF7. The project is addressing the needs of European manufacturing companies of a new model that goes beyond lean manufacturing, to ensure the transformation of the enterprise into lean environment. This is a respond to the market demand of value creation, incorporating sustainability and customisation as well as ensuring business growth through the development of high quality products in a cost effective manner at the shortest time. The authors believe that significant change in enterprise performance can be achieved through the adoption of lean thinking throughout the product life cycle. The paper presents the LeanPPD enablers which represent the building block of the model

High-resolution thickness maps of corrosion using SH1 guided wave tomography

Quantifying corrosion damage is vital for the petrochemical industry, and guided wave tomography can provide thickness maps of such regions by transmitting guided waves through these areas and capturing the scattering information using arrays. The dispersive nature of the guided waves enables a reconstruction of wave velocity to be converted into thickness. However, existing approaches have been shown to be limited in in-plane resolution, significantly short of that required to accurately image a defect target of three times the wall thickness (i.e. 3 T) in each in-plane direction. This is largely due to the long wavelengths in the fundamental modes commonly used, being around 4 T for both A0 and S0 at the typical operation points. In this work, the suitability of the first-order shear-horizontal guided wave mode, SH1, has been investigated to improve the resolution limit. The wavelength at the desired operating point is significantly shorter, enabling an improvement in resolution of around 2.4 times. This is first verified by realistic finite-element simulations and then validated by experimental results, confirming the improved resolution limit can now allow defects of maximum extent 3T-by-3T to be reliably detected and sized, i.e. a long-pursued goal of guided wave tomography has been achieved

Pogo models of axisymmetric and realistic corrosion maps

Pogo model files used in PRSA paper by AAE Zimmermann, P Huthwaite, B Pavlakovic, 2020, 'High-resolution thickness maps of corrosion using SH1 guided wave tomography'.Pogo model files used in PRSA paper by AAE Zimmermann, P Huthwaite, B Pavlakovic, 2020, 'High-resolution thickness maps of corrosion using SH1 guided wave tomography'.