Guy A. Bingham

Comparing additive manufacturing technologies for customised wrist splints

Purpose – The purpose of this paper is to compare four different additive manufacturing (AM) processes to assess their suitability in the context of upper extremity splinting. Design/methodology/approach – This paper describes the design characteristics and subsequent fabrication of six different wrist splints using four different AM processes: laser sintering (LS), fused deposition modelling (FDM), stereolithography (SLA) and polyjet material jetting via Objet Connex. The suitability of each process was then compared against competing designs and processes from traditional splinting. The splints were created using a digital design workflow that combined recognised clinical best practice with design for AM principles. Findings – Research concluded that, based on currently available technology, FDM was considered the least suitable AM process for upper extremity splinting. LS, SLA and material jetting show promise for future applications, but further research and development into AM processes, materials an...

Rapid manufactured textiles

Rapid Manufacturing (RM) is increasingly becoming a viable manufacturing process due to dramatic advantages that are achievable in the area of design complexity. Through the exploration of the design freedom afforded by RM, this paper introduces the concept and novel research area of RM textiles. The paper highlights the design and manufacturing possibilities applied to textiles when considering additive manufacturing techniques, the current limitations of conventional Computer Aided Design (CAD) software when creating RM textile three-dimensional (3D) data and the potential use of dedicated ‘textile CAD’. A methodology for the generation of 3D conformal RM textile articles is presented in addition to the initial investigation of ‘efficient manufacture’ by the collapsing of RM textile structures into their lowest potential energy state. The work concludes that through the utilization of RM it is entirely possible to manufacture a structure that incorporates drape and free movement properties directly comparable with conventional textiles.

Additive manufactured textiles for high‐performance stab resistant applications

Purpose – The purpose of this paper is to ascertain the stab resistance characteristics of a series of planar and articulated laser sintered (LS) samples, in accordance with the United Kingdom Home Office Scientific Development Branch (HOSDB) Body Armour Standard – Publication 39/07.Design/methodology/approach – A series of LS planar samples were manufactured using an EOS P100 Formiga system, manufactured from 100 per cent virgin or a 50:50 mix of recycled and virgin Nylon (PA2200), ranging in thickness from 1‐10 mm. All planar samples were stab tested to the HOSDB knife‐resistance (KR) level one impact energy of 24 Joules, using an in‐house manufactured HOSDB guided rail drop test impact rig and standardised knives. Penetration through the underside of each sample was measured and recorded. These results were then used to develop an articulated, additive manufactured (AM) scale textile – LS from a 50:50 mix of recycled and virgin PA2200 powder. These samples were then tested using the aforementioned impa...

Finite-element modelling of mechanical behaviour of rapid manufactured textiles

Novel textile-like linked structures, realised using a rapid manufacturing (RM) process, have been proposed and developed recently. Various potential applications exist, and in most cases the mechanical performance must be evaluated. The present paper outlines a method to solve this problem by employing finite-element (FE) techniques at two scales, using the results of analysis at the meso-scale (the scale of the repeating unit) to provide equivalent non-linear spring behaviour for each textile link at the macro-scale. Validation with experimental test data from each scale was performed and these results are presented. Initial results overestimated mechanical performance. Microscopy suggested that this may be due to edge porosity in the specimens, and the dimensions of the FE models were adjusted accordingly as an initial approach to account for this. Predictions incorporating this modification exhibited excellent agreement with experimental measurements. The current work demonstrates both a technique, which could be automated for use in the design environment, and the potential value of developing an integrated process simulation to provide local material property data for the FE model.

Meeting the expectation of industry: an integrated approach for the teaching of mechanics and electronics to design students

This paper examines the traditional engineering-based provision delivered to Product Design and Technology (B.Sc.) undergraduates at the Loughborough Design School and questions its relevancy against the increasing expectations of industry. The paper reviews final-year design projects to understand the level of transference of engineering-based knowledge into design practice and highlights areas of opportunity for improved teaching and learning. The paper discusses the development and implementation of an integrated approach to the teaching of Mechanics and Electronics to formalise and reinforce the key learning process of transference within the design context. The paper concludes with observations from the delivery of this integrated teaching and offers insights from student and academic perspectives for the further improvement of engineering-based teaching and learning.

Efficient three dimensional modelling of additive manufactured textiles

Purpose – The purpose of this paper is to investigate, develop and validate a three‐dimensional modelling strategy for the efficient generation of conformal textile data suitable for additive manufacture.Design/methodology/approach – A series of additive manufactured (AM) textiles samples were modelled using currently available computer‐aided design software to understand the limitations associated with the generation of conformal data. Results of the initial three‐dimensional modelling processes informed the exploration and development of a new dedicated efficient modelling strategy that was tested to understand its capabilities.Findings – The research demonstrates the dramatically improved capabilities of the developed three‐dimensional modelling strategy, over existing approaches by accurately mapping complex geometries described as STL data to a mapping mesh without distortion and correctly matching the orientation and surface normal.Originality/value – To date the generation of data for AM textiles h...

Laser sintered body armour: establishing guidelines for dual-layered stab protection

Additive Manufacturing technologies are increasingly being utilised in a range of custom and high performance applications. Initial research has demonstrated the successful use of Laser Sintering for achieving stab protection to UK body armour standards. However, further development is required to establish a comprehensive set of stab resistant design characteristics which could be used for the generation of a bespoke AM body armour garment. This body of work is a precursor to such developments, instead establishing the foundations as to whether dual layered Laser sintered planar structures can be used to minimise body armour thickness requirements, whilst maintaining successful stab protection to internationally recognised standards.

Comparing the penetrative stab performance of the UK HOSDB P1/B and Stanley Tools 1992 trimming blades on certified body armour specimens

This body of research assessed the penetrative stab performance of the United Kingdom Home Office Scientific Development Branch’s (HOSDB) P1/B certified blades against the readily accessible Stanley Tools 1992 trimming blade. All tests were performed against the HOSDB KR1-E1 impact energy of 24 Joules on HOSDB KR1 certified body armour specimens. Results demonstrated that the Stanley 1992 trimming blade posed a 30% greater stab threat in comparison to the HOSDB P1/B blade. This paper demonstrates the threat imposed by readily available utility blades and a requirement to enhance existing stab resistant body armour test procedures.

Product personalisation using personally meaningful data and the creation of new product attributes

Some additive manufacture processes can be used to fabricate personalised products. Commercial companies have formed that exploit this fabrication potential, creating co-design environments that allow users to personalise and customise product geometry in new ways. Work carried out at the intersection of art and design takes this a step further, exploring ways in which objects form can be transformed using complex data sets. Interactions that facilitate product personalisation (PP) using data that is meaningful to the owner could stimulate the formation of product attachment, which in turn could extend a products lifespan. However, this new PP potential could lead to the formation of new product attributes that must be mediated by both the designer and the user. This paper explores examples of product/data synthesis and uses them to propose three product attributes that could result from data-driven PP: abstractness, visibility and obtrusiveness.

The design and assessment of bio-inspired additive manufactured stab-resistant armour

ABSTRACT The performance of modern fibre-based or polycarbonate armour has significantly improved since their introduction, providing protection against a range of low- and high-velocity threats. While this is so, users of such armour frequently report of issues relating to their operational suitability resulting in impaired performance and physiological effects. Recently, researchers have focused on how naturally occurring protective mechanisms could be utilised to enhance the protective and operational performance of wearers of engineered body armour. The research presented within this paper therefore utilises a series of key design characteristics exhibited within naturally occurring elasmoid scale armour, coupled with established laser sintering manufacturing parameters, for the realisation and assessment of a scale-based stab-resistant armoured structure to internationally recognised test standards.