Dmitry S. Ivanov

This research examines the resilience paradox in global supply chains, exploring how trade‐offs between economic and social‐ecological resilience escalate into managerial dilemmas under high environmental uncertainty. Using an abductive theory extension approach, we analyse a multinational automotive supply chain case during the Covid‐19 crisis through a real‐time Delphi study with managers from OEMs, suppliers, importers and retailers, supported by archival and observational data. The results show that organisational and environmental constraints, including resource scarcity, power dependencies, measurement systems and conflicting stakeholder demands, can intensify crisis‐induced trade‐offs. These trade‐offs are associated with ethical dilemmas and temporarily unsustainable performance outcomes such as increased emissions, workforce strain and reduced sustainability investments. Our findings suggest that ethical sensemaking supports managers to move from crisis‐induced trade‐offs towards multilevel paradoxical response strategies. The study extends paradox theory by identifying ethical dilemmas as managerial‐level manifestations of undecidable crisis‐induced trade‐offs, showing how ethical sensemaking connects these dilemmas with multilevel paradox response strategies and identifying the crisis conditions under which the resilience paradox becomes salient.

Squeeze-flow testing is a commonly used experimental method for characterising the flow behaviour of high-performance C-SMCs under typical compression moulding conditions. A European benchmark exercise involving 14 research institutes is currently being conducted to identify the sources of variability in squeeze flow testing results and to support the development of a standardised testing methodology. Experimental testing of five C-SMC materials has been completed using a well-defined testing procedure.This paper focuses on the data processing stage of the benchmark exercise, in which experimental data collected from all participants are processed and analysed to extract information on raw material variability, force–gap height relationships, and flow-front profiles. Qualitative assessment of these results is used to identify the critical sources of variability, which subsequently informs a more detailed statistical analysis.

Novel multifunctional resins and composites present multiple manufacturing challenges that need to be overcome to allow for wider adoption. These challenges include high viscosity, short cure windows, low permeability preforms, and non-standard cure kinetics. Standard liquid composite molding methods (such as resin infusion under flexible tooling [RIFT], resin transfer molding [RTM], or compaction-RTM) are poorly equipped to manufacture these new materials. A new system is presented that combines the abilities of RIFT/RTM/c-RTM while introducing controlled deformation of the preform during infusion to remove flow through the preform. This manufacturing method allows the preform to lie uncompacted, while still under vacuum, during infusion which allows resin to flow unrestricted between plies. Then once infusion has occurred, compaction proceeds to produce the final composite geometry. This method has been successfully implemented to manufacture structural power devices with a biphasic resin system and metal coated carbon aerogel preform, as well as a vitrimer composite with a high-viscosity/short-cure resin thought high weight carbon fiber preform. The novel and flexible manufacturing parameters of this new system present a low-cost route towards optimizing the manufacture of challenging and novel resin systems, allowing for a faster understanding and implementation of these materials.

Forming of dry textile preforms for liquid moulding processes becomes increasingly challenging for geometries exhibiting strong double curvature and aggressive tapering. While sequential draping can mitigate defects, it is often impractical for high-rate manufacturing and lacks robustness for dry fabrics with limited inter-ply tack. This paper investigates an alternative approach in which locally printed and cured or semi-cured resin patches are used to steer deformation during forming and suppress shear localisation. A numerical framework is developed to model patched preforms using a superposition-based material representation and is applied to an extreme “bow-tie” benchmark geometry. Initial simulations reveal severe shear-strain localisation leading to fibre-path instability. Various patching strategies are explored to identify the dominant drivers governing defect mitigation. The results demonstrate that appropriately placed and sufficiently stiff patches can significantly delocalise shear and eliminate multi-stripe deformation patterns. Based on these findings, key optimisation parameters and practical guidelines for patch placement and stiffness selection are formulated, providing a foundation for future automated optimisation of patch-assisted preform forming.

To address classical forming challenges, such as the susceptibility of highly compliant precursors to defects, we proposed the concept of modular forming, where formable zones are integrated into a fully cured blank of a composite structure. Reconfigurable vitrimer matrices are integrated in targeted regions that include embossed areas to accommodate generation of excess material during forming. Consequently, the structural blanks can be manufactured nearly flat and later assembled, thereby minimizing defect risks from infusion and localized ply deposition and, potentially, giving other benefits such as enabling cost-effective shipping. The effectiveness of this forming process depends on precise control of processing parameters and embossment geometry, hence computationally efficient modelling tools are required to optimise the process. To address this requirement, we employ an embedded element approach mostly used in structural multi-scale problems. The mesh of viscous host matrix (epoxy or vitrimer) is created independently of the mesh of discrete elastic plies. The coupling of these volumes prevents relative motion of plies in fully cured regions while permitting relative motion in embossed vitrimer zones – both reflecting physical behaviour. The deformations obtained from the model agree well with those from experiments, demonstrating the effectiveness and computational efficiency of the new modelling approach.

The formation of porosity is a major challenge in any composite manufacturing process, particularly in the absence of vacuum assistance. Highly localized injection of polymer matrix into regions of interest in a dry preform is a route to manufacturing multi-matrix fiber-reinforced composites with high filler concentrations, which are otherwise difficult to achieve. Unlike traditional composites, such multi-matrix fiber-reinforced composite systems, which combine multiple resins in continuous form, offer improved structural performance around stress concentrators and multifunctional capabilities. As the process lacks vacuum assistance, porosity becomes a primary issue to be addressed. This paper presents a rheo-kinetic coupled rapid consolidation procedure for optimizing the quality of localized matrix patches. The procedure involves manufacturing trials and analytical consolidation models to determine the best processing program for minimal voidage in the patch. The results provide a step toward an efficient manufacturing process for the optimal design of multi-matrix composites without the need for complex vacuum bag arrangements, thus reducing cost and time while opening avenues to improve overall composite performance.

DcAFF (discontinuous aligned fibre filament) is a novel material for fused filament fabrication (FFF) 3D printing made of highly aligned discontinuous fibres produced using high performance discontinuous fibre (HiPerDiF) technology. It reinforces a thermoplastic matrix to provide high mechanical performance and formability. Accurate printing of DcAFF poses a challenge, especially for complex geometries, because: (i) there is a discrepancy between the path where the filament experiences the adhering pressure from the filleted nozzle and the nozzle path; and (ii) the rasters display poor adhesion to the build platform immediately after deposition, which causes the filament to be dragged when the printing direction changes. This paper explains the implication of these phenomena on steering capabilities and examines the techniques for improving DcAFF printing accuracy. In the first approach, the machine parameters were adjusted to improve the quality of the sharp turning angle without changing the desired path, but this showed insignificant effects in terms of precision improvements. In the second approach, a printing path modification with a compensation algorithm was introduced. The nature of the inaccuracy of the printing at the turning point was studied with a first-order lag relationship. Then the equation to describe the deposition raster inaccuracy was determined. A proportional–integral (PI) controller was added to the equation to calculate the nozzle movement in order to bring the raster back to the desired path. The applied compensation path is shown to give an accuracy improvement in curvilinear printing paths. This is particularly beneficial when printing larger circular diameter curvilinear printed parts. The developed printing approach can be applied with other fibre reinforced filaments to achieve complex geometries.