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Due to recent developments in the additive manufacturing industry, topology optimization is nowadays a powerful computational tool that allows to design feasible lightweight components. Although the Finite Element Method (FEM) is the most applied discretization technique, meshless methods are currently established as accurate numerical methods with relevant advantages in several engineering fields. Nonetheless, the state-of-the-art of meshless methods in topology optimization is still scarce. This work develops the combination of a bi-direction structural optimization (BESO) algorithm with the Natural Neighbour Radial Point Interpolation Method (NNRPIM), a meshless method combining the natural neighbours geometric concept with the RPI shape functions. First, several benchmark examples are solved to evaluate the algorithm capability under several algorithm parameters. The proposed methodology is then implemented to design new automotive lightweight components. The results from the numerical applications demonstrate that the NNRPIM is a solid technique to be incorporated in optimization algorithms. Additionally, innovative automotive industry designs for additive manufacturing can be obtained using the presented approach.

Nowadays, the adhesive bonding process takes an important place in several industrial fields, especially in aeronautics. Given its advantages over other conventional mechanical processes, this process is being extended to be applied in composite materials and, in recent years, more particularly in the bonding of functional graded materials (FGM). Current research aims to optimize the mechanical properties of the substrates and the adhesive to minimize stress concentrations in the adhesive joint, which is the weak link of the structure. The present work analyzes, by the finite element method (FEM), the mechanical behavior of a single-lap joint with varying nature of the substrates. The analysis takes into account the variation of stresses in the adhesive of a bonded joint of different types (metal/metal, composite/composite, FGM/metal, FGM/FGM). On the other hand, an attempt has been made to introduce an adhesive with graded mechanical properties made up of two types to ensure efficient joining and reduce stress concentrations at the bond edges. The introduction of the FGM substrate mechanical properties is done using a USDFLD subroutine implemented in the ABAQUS computer code. Different damage approaches were used for the adhesive, namely the virtual crack closure technique (VCCT) and cohesive zone models (CZM) techniques. The effect of the mechanical properties of the substrates and adhesive were considered. The results show clearly that the value of the different stresses can be reduced if the mechanical properties of the substrates are optimized. On the other hand, the different techniques used to model the bonded joint converge towards the same results, emphasizing the agreement of the load-displacement curves with the experimental test, and the variation of the stresses according to the lap length with analysis by analytical models.

Understand the behaviour of a joint under dynamic loads is a hot topic in the research community. This work studies numerically and experimentally the effect of the adhesive type and overlap length (LO) on the strength of adhesively bonded single lap joints (SLJ) under impact loads. Araldite® AV138 and Sikaforce® 7752, two adhesives with different ductility were used to bond unidirectional composite adherends. Drop weight tests were performed and simulated using a cohesive zone model (CZM) approach. It was concluded that increasing the LO increases the joint strength. This effect is more notorious in joints with more flexible adhesives.

The production of stamping dies requires the manufacture of numerous components, many of which have similar dimensions. However, because they are almost all different, this brings added problems in the acquisition of materials, and in their machining, the main process used in the manufacture of these components. Most SMEs do not have production systems properly organized to manage the machining of these components in the most cost-effective way. The purpose of this work is to provide a novel tool able to re-organize the machining operations in the production of dies for stamping operations, saving time and allowing an easy way to extend the autonomous machining time. This work follows an empirical approach resulting from the experience and attempts to optimize machining operations in the production of stamping dies. A flowchart was developed, acting as guidelines to select if the set of parts to be manufactured can integrate the approach designed. The approach is validated by two case studies presented in the paper.

Tires are a highly relevant component in the industry of global mobility. Also, in the automotive industry, they play a key role. They are a composite structure formed by multiple layers of different materials such as rubber compounds, steel wires and polyamide cords. Between the tire tread and steel belts, a cap ply layer is used to restrict the tire’s expansion due to centrifugal forces. The cap ply is manufactured by a process where polyamide cords are impregnated with a rubber compound, which is extruded. When the extrusion phase of the rubber compound is poorly controlled, the cap ply belts show premature vulcanization or lack of impregnation signs. These defects compromise the overall quality of the tire, as well as its safety features to its user. To improve the production process of cap ply, a CFD (Computational Fluid Dynamics) analysis was performed to study the flow of the rubber compound inside the extruder head by using two different temperature controls. The vulcanization and rheological properties of the rubber compound were studied to support numerical analysis data. Through thermographic imaging and data collection with a portable device (Arduino UNO) connected to sensors and modules, experimental data related to the temperature distribution was analyzed together with the numerical analysis. By critically analyzing all the data obtained, a new temperature control was created, which proved to be extremely efficient, reducing the amount of scrap and electric energy consumed.

Fatigue crack propagation is an undesirable phenomenon that may lead to catastrophic failures in many components and structures, therefore it is important to understand its underlying mechanics. To that effect, systematic parametric studies of fatigue crack propagation laws are interesting to determine how fatigue life varies with the constants that define the mechanical behavior of a given material in a fatigue situation, such as the Paris’ law constants, fracture toughness (Kc) or the stress range ??. The parametric studies performed in the present work assess the influence of several parameters, assuming that failure occurs when K>Kc, but also when all the material ahead of the crack is yielding. It was found that m and C, the Paris’ law parameters, are the most influential parameters in terms of fatigue life. The present study should help future designers when choosing materials for components or structures subjected to cyclic loads.

Structural adhesives and the joints involving them are often analysed using elastic and elastic-plastic material models. Nowadays, flexible adhesives are being used for structural applications. The material models used for structural adhesives are not always suitable for flexible adhesives. Hyper-elastic material models had been proven more suitable to model flexible adhesives. The Finite Element Method (FEM) is a well-accepted technique to model and analyse adhesive joints. Commercial FEM packages already have hyper-elastic capabilities, but not many applications to adhesive joints had been studied. Recently, Meshless Methods (MM) have also been brought into this field. Although the nature of MM made them attractive for the analysis of flexible adhesives and the joints bonded with them, no previous analyses had been reported. Several hyper-elastic models are available. One of them, the Ogden model, can represent several models through converting their parameters. Therefore, the Ogden model implementation is more versatile. In this work, the Ogden hyper-elastic model was implemented into a MM, the Natural Neighbour Radial Point Interpolation Method (NNRPIM). The implementation was validated using literature data. The proposed methodology could be the basis for further application to adhesive joints bonded with flexible adhesives.

The use of adhesive bonds has increased significantly in recent years and is now a predominant bonding technique in the aeronautical and automotive industries. Cohesive Zone Models (CZM), used together with the Finite Element Method (FEM), are a viable tool to predict the strength (Pm) of adhesive joints. The CZM combines strength criteria for damage initiation and fracture mechanics concepts for crack propagation. The main objective of this study is to numerically and experimentally evaluate the mechanical performance of adhesively-bonded stepped-lap joints with carbon-fiber reinforced plastic (CFRP) substrates under tensile loading. The influence of different overlap lengths (LO) and a ductile adhesive was also investigated. Experimental data was gathered and compared with numerical CZM results obtained using Abaqus®. A study of peel (σy) and shear (τxy) stresses in the adhesive layer was performed. A significant geometry effect was found on the maximum load (Pm) of the stepped-lap joints, with benefit for large LO; however, delamination should be taken into account mostly for the longer LO. The CZM technique was revealed to be a suitable tool in determining the behavior of composite stepped-lap joints.

The market requirements impose searching for new joining solutions, which must be simple and effective. Adhesive joints are currently used, for example in the automotive and aeronautical industries, since welding is not possible in many cases and because drilling the base materials is not required. To analyse adhesive joints, the Finite Element Method (FEM) is increasingly used. The Extended Finite Element Method (XFEM) is able to predict crack growth and joint strength in adhesive structures. However, there are still not many case studies about its suitability. On the other hand, hybrid joints, which combine spot-welding with adhesive bonding, are being increasingly used in different industries. This study has the purpose of validating the XFEM to predict the performance of T-peel hybrid joints between DIN C45E steel adherends under tensile loads. A comparison is made with spot-welded and adhesive joints. Three adhesives are tested (Araldite® AV138, Araldite® 2015 and Sikaforce® 7752). Different damage initiation and growth criteria, and also damage law shapes, were evaluated for strength and dissipated energy predictions. The joints’ performance was found to highly vary between adhesives and bonding method, and the XFEM analysis is accurate for specific modelling conditions.

Adhesive joining is currently a very popular joining method. This increases the necessity for better strength prediction tools to aid in the design of these joints. Currently, Cohesive Zone Modeling (CZM) is the most popular method to study joint strength. However, CZM requires traction-separation laws, which define the adhesive behavior, and these are dependent on the adhesive thickness (tA). This means that, when using CZM, the traction separation law parameters have to be measured multiple times to predict the strength of joints with different tA. The recently proposed Critical Longitudinal Strain (CLS) criterion is a criterion based on continuum mechanics, which was previously used with the Finite Element Method (FEM) to predict the strength of Single Lap Joints (SLJ). The use of meshless methods to predict the strength of adhesive joints is scarce and the CLS criterion has never been used with the Radial Point Interpolation Method (RPIM). In this work, the CLS criterion was used with the RPIM to determine the strength of SLJ bonded with three different adhesives. The strength predictions with this approach were accurate for the three adhesives, which ranged from brittle to highly ductile.

Thermoplastic injection is currently employed in different industrial fields. This process has significantly evolved over the years, and injection machine manufacturers are continuously forced to innovate, to improve the energetic efficiency, aiming to reduce costs, improve competitiveness, and promote environmental sustainability. This work focuses on the development of a novel, profitable, and environmentally friendly plastic over-injection equipment of small metallic parts for the automotive industry, to be applied in a bowden cable production line, to cover the zamak terminations with plastic, or produce terminations entirely made of plastic. The work is based on an over-sized existing solution. The operating parameters required for the work are quantified, and all machine parts are designed separately to achieve the required functionality. Known approaches are finally used to perform the cost analysis, calculate the return on investment (ROI), and energetic efficiency, to substantiate the replacement of the current solution. The new equipment was able to increase the energetic efficiency of the current assembly line while keeping the required injection rates. An efficient and sustainable solution was presented, with a ROI of 1.2 years over the current solution. The proposed design is also applicable to different automated production lines that require this technology. Nowadays, this concept can be extended to all fields of industry that employ injection molding in their processes, enabling to integrate new manufacturing systems, and increasing energetic efficiency while reducing production costs.

In a market constantly changing and more demanding, the need to have any production cycle working without flaws is more important than ever. Thus, maintenance operations have taken an increasingly important role. However, different organizations may take different approaches depending on their area of business, legal aspects, as well as the company policy. Even though some concepts such as Total Productive Maintenance (TPM) and quality tools are normally used in most of the companies, there are no standard procedures or defined ways for using them across industries. Thus, it is usual many organizations implement statistical tests in order to see whether or not those improvements were successful. This paper intends to establish a procedure to be used across organizations, improving their maintenance procedures. This procedure establishes the correct sequence of tools to be used in the improvement process, conducting the maintenance operations to a higher level of efficiency and effectiveness, allowing to determine if the implemented improvements were successful, or if a different approach needs to be implemented.

To increase the confidence in the design of adhesive structures, it is important to be able to accurately predict their strength and fracture properties (e.g., critical strain energy release rate in tension, JIC, and shear, JIIC). Since in most cases the applied loads induce mixed-mode crack growth, it is highly relevant the perception of fracture under these conditions. This work presents an experimental study using the Single-Leg Bending (SLB) test on specimens bonded with Araldite® 2015, to study and compare the mixed-mode fracture properties. For this purpose, the J-integral method was applied to estimate the tensile (JI) and shear fracture energy (JII). Framing the obtained values in the fracture envelope enabled to select which power-law failure criterion is more appropriate for the Araldite® 2015. Moreover, the tensile and shear cohesive zone model (CZM) laws were obtained for the adhesive by the direct method. Overall, a very good agreement on the fracture properties was obtained between specimens. The CZM laws also showed a good correspondence between specimens, resulting in a novel methodology for integrated mixed-mode material characterization of structural adhesives for possible use to design adhesive joints.

The automotive industry is one of the most demanding sectors of the global market. The level of competitiveness in the sector generates a constant need for improvement in efficiency, productivity and quality, in order to meet customer’s requirements. In this sense, the need to automate processes arises, investing more and more in dedicated or flexible systems, but increasingly relying less on the manpower factor and associated variability, both in terms of cost and quality. This work aimed to develop a new equipment concept for the manufacture of automobile Bowden cables, based on a concept currently in operation. Thus, a flexible equipment was developed, with several changes and improvements implemented, including new operations, and increasing the level of automation of the system. Through the new developed concept, there is less dependence on manpower factor and associated variability, there is an increase in the quality of the product and operator work, a reduction in cycle times (25%) and an increase in productivity.

Nowadays the Industry is becoming increasingly competitive with the emergence of even more advanced technologies. This environment leads the companies to look for a bigger availability of the assets, a higher quality of the products and consequently less costs. Thus, is because of this purpose that Maintenance is becoming even more fundamental. The focus of this paper was to develop a strategy of Predictive Maintenance on a Machine Tool with the aim of reducing the unplanned stops, increasing the productivity and creating the bases for an Industry 4.0 environment in the short term. Thus, a model has been created in order to fulfil this goal. The first step was the selection of the critical component of the machine tool that would be studied. In the next phase the variables that will be monitored were selected and their trigger limits. Finally, the necessary components to monitor this system were chosen. In order to reach the objective, a system of condition-based maintenance where the acoustic emissions and vibration of the bearing of a machine tool were monitor was proposed.

30th International Conference on Flexible Automation and Intelligent Manufacturing (FAIM2021) 15-18 June 2021, Athens, Greece., The products related to automotive industry need to be extremely competitive. The metallic wire ropes used to open doors in the vehicles are based on a braided wire rope provided with accessories. The more expensive is the vehicle, the more complex is the required final wire rope. In order to prevent the corrosion and reduce noise, the internal metallic cable can be coated with a polymer via extrusion. However, this coating needs to be removed from the extremities of the metallic cable, allowing the zamak injection of the mechanical terminals, preventing die casting defects. Nevertheless, the standard machines able to produce the mechanical terminals by die casting process were always prepared to work only with non-coated metallic cable. Customers demanding coated metallic cables impose the need to adapt the standard machines to this new reality. Thus, new systems needed to be added to the standard machine, allowing the metallic cable strip operation. Moreover, this operation needs to be added to the process but without repercussions on the cycle time. Different approaches were studied and tested in order to find the best solution. The new device was designed and produced, allowing its test in real conditions. The system based on just one blade did not show satisfactory results, being necessary the use of a system based on multiple blades. The new device, when connected to the standard machine, allows to produce wire ropes up to 2.5 meters long, striped in both sides, letting the die casting injection of the zamak terminal in one extremity, with a cycle time of 7 seconds (1000 wire ropes per hour, as they are produced in couples)., The authors would like to thank Mr. Mário Cardoso for his support and commitment with this work, providing all data necessary to carry out this development. The authors would like to acknowledge financial support from Fundação para a Ciência e Tecnologia (grants: UID/EMS/00667/2019 and UID/UIDB/CPO/04058/2020

In a big company, project management (PM) is always present. Traditional predictive PM approach is concerned with planning everything in advance and then controlling and adjusting if necessary, throughout the project timeline. This may work well when the requirements are well established, but for maintenance projects brings inherent uncertainty. When the subject is aircraft maintenance, it is almost impossible to plan everything at the beginning and expect that it will occur as planned because however a scheduled maintenance plan exists, according to statistics 60% of the aircraft total failure can only be found with ground inspection which means, that even if a plan is established before receiving the aircraft, it will most certainly need to be significantly changed. This requires a big effort from the planning team to plan everything right and ensure that all tools and resources are available to perform the required tasks. To solve this issue, in this paper we propose a hybrid project management approach developed to a case study company from the aircraft repair sector, to enable a faster planning while taking into account the priorities and dependencies of the inherent project tasks with the available resources.

The automotive industry is considered one of the most demanding and competitive sectors in the global market. This increasingly implies having a stable and optimized production process, always with a view to continuous improvement. Therefore, it is very important to be aware of all the waste that is generated in all production and logistics operations and take action to reduce them. In this regard and considering the process of producing air conditioning pipes for the automotive industry, a high scrap value was detected mainly due to soldering process. Therefore, the entire production process is analyzed in order to identify the main causes behind the high scrap value. Several Lean and quality tools are used to reduce not only the amount of scrap but also to increase the line productivity. In order to face this challenge, after elaborating the action plan and corresponding implementation, the scrap value is reduced by 12% in general, and productivity increased by 29%, 55% and 22.5% in three different references produced by the same machine. Although this solution is a bit expensive, the corresponding payback is reduced, so it can easily be applied transversally to other similar machines allowing extremely interesting gains in the short term.

Transport is Europe is a biggest source of CO2, being responsible for the emission of over a quarter of all greenhouse gases. Unless transport emissions are brought under control national 2030 climate goals will be missed. To meet the 2050 Paris climate commitments cars and vans must be entirely decarbonized. This requires ending sales of cars with an internal combustion engine by 2035. Big challenges and huge efforts between all stakeholders are needed. Governments are, almost universally, unwilling to constrain demand for mobility and, in particular, car use and ownership. The future demands paradigm changes and better education for sustainable development. The present work aims to present a study on the currently used main vehicle motorization technologies, namely, the vehicles with internal combustion engines (ICE), electric motors (EM), electric-hybrid vehicles (EHV) and vehicles fuel cells (VFC), regardless of the technology diffusion. The main objective of this study is to point out the best model to help reduce the amount of pollutant gas emission as well as contribute to public policy decision making. After a literature review, a Sustainability Index was applied to select a set of sixteen models of different brands and categories. The used management tool is the Hierarchy Process (AHP). After discussion of results, conclusions are presented.

Lean in project management is an essential methodology for success in the automotive industry. This industry, usually, focuses its strategy in continuous improvement, governed by the Japanese model, the Toyota Production System (TPS). The challenge of this work was the industrialization of a component for an automotive OEM customer, respecting the quality and price ratio. This project was carried out focused on the use of the DMADV methodology in the management of an industrialization project regarding an updated part for the automotive industry. Thus, the process was mapped in detail, using five main steps: Define, Measure, Analyse, Design and Verify. The product corresponds to a piping system for air conditioning of motor vehicles. Its production in series needed a strong improvement in order to fulfill the demanding program required by the market and comply with the quality - price ratio. It was concluded that the project allowed the development of prototypes from the embryonic stage (2D) to the final design. During the industrialization project, finished prototypes were shipped to the customer following the milestones required by the customer, without any nonconformity in the final product. At a later stage, the transition from industrialization to serial production was successfully completed.

This paper aims to find low-cost solutions for the automatic inspection and packaging of an integral part of vehicles, called the suspension mat. This automation substitutes the manual labor and is integrated onto the assembly line of suspension mats which is, aside from the inspection and packaging, fully automated. Through careful analysis of the possible solutions for the delivery and inspection of the part, being a robotized operation and the cheaper automatic systems, automatic systems are used for the inspection and an industrial robot for the delivery of the suspension mat. Through this developed concept, manual labor is eliminated, thus eliminating the labor cost as well as increasing the reliability, productivity and efficiency of the inspection and delivery of the component.

Huge constructions mostly contain different profiles to form a structure. These profiles can appear in different forms and sizes, but also the used materials can vary. For this case steel “T”-profiles are used. Before, the “T”-profiles were welded manually with conventional welding techniques. The novel design of a machine that can automatically laser-weld “T”-profiles of up to six meters in length is will be presented. The design of this equipment was done using AUTODESK software, FUSION 360. The machine presents a modular concept, containing four parts with different functions: the loading, the vertical centring, the welding, and the unloading. The loading and the unloading of the plates is performed manually with the use of a roller bridge. A lift system is designed to ease the loading of the plates and to clamp the vertical one after the loading is done. A centring system makes it possible to put the horizontal and vertical plates in the desired position. The clamps are wheels, so that the plates roll, and the clamps cannot interrupt the laser beam during the welding. A pressing system excludes possible gaps between the two plates in the welding zone. Extendable feet make it possible to level out the whole machine and the alignment is done with the use of low-cost brackets.

The automotive industry has evolved, becoming increasingly demanding. Thus, it becomes necessary to increase the availability of equipment, reacting efficiently to be able to respond to customer requests. Nowadays, the strong development of this industry is based on three main pillars: competitiveness, product quality and response time to requests. The focus of this work is to increase the availability of a deep drawing machine with extremely high setup time, with the main objective of reducing the average setup time by 20%. This reduction is even more important when it comes to the internal setup time, the time the machine is stopped. Thus, the Single-Minute Exchange of Die technique was applied and work standards were improved to reduce the equipment setup time, increasing the machine availability, leading to a production increased output. As a result of this work, it was possible to standardize setup, reducing 38% of total machine setup time, 53% of internal setup time and increasing 7.7% of OEE (Overall Equipment Effectiveness) availability.

Adhesive bonding is a widespread joining technique in the industry, namely aeronautical and automotive. However, the associated products often have complex and non-standard shapes. Numerical modeling, such as that based on the finite element method (FEM), is commonly applied for bonded joint design, although there are still limitations linked to the method. Meshless methods (MM) are a viable option to overcome some limitations of the FEM. However, these methods are still in development. In this work, a robust meshless method, the Natural Neighbor Radial Point Interpolation Method (NNRPIM), was applied to the analysis of adhesive joints. First, experimental data of single-lap joints (SLJ) corresponding to four overlap lengths (LO) and a brittle adhesive were measured as a benchmark. Then, all the joint geometries were simulated utilizing the FEM and NNRPIM methodologies. The NNRPIM proved to be a good alternative to the FEM, providing similar strength prediction with differences less than 3% between them. Moreover, the stress distribution curves were compared, and differences of 6% in the peak shear stresses were found. In conclusion, the NNRPIM provides accurate results and could be utilized for further study of adhesively bonded joints.

The use of adhesive bonds greatly increased in industrial applications, as they have multiple advantages compared to other more traditional bonding methods (fastened, welded and riveted joints). The number of approaches to predict the strength of adhesive joints has increased over the years. The eXtended Finite Element Method (XFEM) is a recent variant of the (Finite Element Method) FEM to model damage growth in structures, although it is yet seldom studied within the context of bonded joints. This work consists of an experimental and XFEM analysis of aluminium alloy T-joints, adhesively-bonded with three adhesive types. A parametric study is undertaken regarding the curved adherends’ thickness (tP2), with values between 1 and 4 mm. The adhesives Araldite® AV138, Araldite® 2015 and the Sikaforce® 7752 were tested. A comparative analysis between the different joints conditions was performed, too. The XFEM predictive capabilities were tested with different damage initiation criteria. It was found that, provided that the modelling conditions are properly set, accurate numerical results can be found.

In this work, a new crack propagation prediction algorithm is combined with two distinct meshless methods – the Radial Point Interpolation Method (RPIM) and the Natural Neighbor Radial Point Interpolation Method (NNRPIM). Both these advanced discretization numerical techniques construct the shape functions using the radial point interpolating technique, which allows to build shape functions possessing the delta Kronecker property. The RPIM requires a background integration grid to numerically integrate the partial differential equations ruling the physical phenomenon. Alternatively, the NNRPIM constructs the background integration points using only the information of the spatial position of the nodes. This work aims to present a new methodology to predict the crack propagation and, simultaneously, to compare the performance of both meshless techniques (for similar conditions). The developed algorithm advances the crack tip iteratively and uses the maximum tangential stress criterion to calculate the propagation direction. In the end, three benchmark tests were analyzed using the proposed algorithm. Accurate crack paths were obtained when compared to the solutions described in the literature.

Aiming to predict the strength of bonded joints by techniques such as cohesive zone models (CZM), it is highly relevant to estimate the adhesive strength and fracture toughness (GC). Here, ...

To increase the confidence in the design of adhesive structures, it is important to be able to accurately predict their strength and fracture properties (e.g. critical strain energy release rate in...

The use of adhesive bonds greatly increased in industrial applications, as they have multiple advantages compared to other more traditional bonding methods (fastened, welded and riveted joints). The number of approaches to predict the strength of adhesive joints has increased over the years. The eXtended Finite Element Method (XFEM) is a recent variant of the (Finite Element Method) FEM to model damage growth in structures, although it is yet seldom studied within the context of bonded joints. This work consists of an experimental and XFEM analysis of aluminium alloy T-joints, adhesively-bonded with three adhesive types. A parametric study is undertaken regarding the curved adherends’ thickness (tP2), with values between 1 and 4 mm. The adhesives Araldite® AV138 (strong but brittle), Araldite® 2015 (less strong but moderately ductile) and the Sikaforce® 7752 (with the smallest strength but highly ductile) were tested. A comparative analysis between the different joints conditions was undertaken by plotting peel (sy) and shear (txy) stresses, and analysing the damage variable. The XFEM predictive capabilities were tested with different damage initiation and propagation criteria. It was found that, provided that the modelling conditions are properly set, accurate numerical results can be found.

Nowadays, any structure must have strength, robustness and lightness, which has increased the industrial interest and research efforts in adhesive joining, mainly in the improvement of strength and fracture properties of adhesives. Thus, in recent years, the use of adhesive joints in industrial applications has gradually grown, replacing some traditional bonding methods, since they have advantages such as reduced stress concentrations, reduced weight and cost, and ease of processing/manufacturing. In this work, the cohesive laws of three adhesives, Araldite® AV138, Araldite® 2015 and Sikaforce® 7752, were obtained by the application of an inverse adjustment method between the numerical and experimental load-displacement curves (P-d) of Double-Cantilever Beam (DCB) tests for tensile characterization and End-Notched Flexure (ENF) tests for shear characterization. Next, these laws were validated with experimental data of single-lap joints (SLJ) and double-lap joints (DLJ), using Abaqus®. For the Araldite® AV138 and Araldite® 2015, in tension and shear, the triangular law accurately predicted the behaviour of the SLJ and DLJ. For the Sikaforce® 7752, the triangular law did not suitably fit the experimental results. It was considered that, due to its ductility, the Sikaforce® 7752 is best modelled with a trapezoidal law.

In this work, a model based on the combination of two approaches XFEM and CZM , has been used to predict the damage of repairs by composite patch (patch/adhesive/plate assembly). This degradation is analyzed in terms of adhesive damage considering both initiation and propagation of interfacial debonding . The interfacial cohesive zone of the patch/adhesive/plate system is defined by its cohesive properties and its resistance to debonding estimated from the displacement-load curves. This study highlights, as a function of the adhesive properties of the plate/patch interface, the competition between two degradation mechanisms : adhesive damage (through a mechanism of initiation and propagation of patch debonding from the plate) and plate damage (through a phenomenon of crack initiation and propagation emanating from notch). It also highlights, depending on the nature of the interface, four physical parameters: the bending deflection of the repaired plate, the displacement path of the patch-reinforced plate, the debonding resistance and the interfacial shear stresses , characteristic of the adhesive joint damage and their interactions with the interface. This is the originality of this study. Results show that XFEM simulations based on the CZM model allow adequate prediction of the damage of the patch/adhesive/plate assemblies.

Adhesive joints are widely used in the production of goods, mainly in the transport industry. However, their industrial applications often have non-standard complex shapes. Computer simulation, like the finite element method (FEM), is widely used for their analysis but limitations still exist. Meshless methods have been in development and offer an option to overcome some limitations of the FEM; however, these are still in development. In this work, an efficient meshless method, the ‘natural neighbour radial point interpolation method’ (NNRPIM), has been applied to the analysis of adhesive joints including an elasto-plastic formulation for the adhesive. First, experimental data corresponding to four overlap lengths (\(L_O\)) and two different adhesives were measured, as a benchmark. Afterwards, joint strength (\(P_{\mathrm{max}}\)) was analytically obtained as a second benchmark. Then, all the joint geometries were simulated utilising the FEM and NNRPIM methodologies, and \(P_{max}\) were calculated from those simulations. Finally, the results were compared against the first and second benchmarks. The meshless method proved to be a good alternative to the FEM, providing similar strength prediction. Moreover, the stress distribution curves were compared. In conclusion, the NNRPIM provides accurate results and could be utilised for further study of adhesively-bonded joints.

In a market as competitive as the automotive industry, it becomes increasingly important for the organizations to adopt a culture of continuous improvement, which should cross-over all stakeholders in the organization. The continuous improvement of the processes, the increase in efficiency, and the elimination of waste, leads to a considerable increase in market competitiveness, not only economically, but also technologically. The focus of this work was the optimization of a production line, with the main goal being the increase of its productive capacity, so that it can comply with customer’s requests. Thus, it was defined as a goal of this project: to increase the productive capacity to 1800 parts/day. The methodologies used were based on several continuous improvements and lean techniques, such as line balancing, standard work, visual management and 5S. The work developed allowed an increase of 37% of the production line capacity and an increase of 22% in the OEE of the production line.

Maintenance function assumes a key role in today’s industry. The automotive industry is not an exception and there are strict rules to comply with. Indeed, the IATF 16949:2016 imposes the implementation of key performance indicator as a mean to control the overall manufacturing performance. This work presents a case study carried out in a multinational company related with the production of parts for the automotive industry where it was necessary to implement key performance indicators to comply with the IATF 16949: 2016 standard and a model was also created for the management of spare parts linked to the maintenance of existing equipment. The introduction of these changes forced the application of some Lean tools, with a view to improving procedures and information flows. The work was completed successfully, and key performance indicators were implemented, whose support data, which is now collected and calculated automatically on a routine basis, and the spare-parts management was validated with a view to optimization of warehouse space and at a conveniently low inventory level in this type of parts, without endangering critical equipment in production. The SMED methodology was applied, which allowed the setup time to be reduced by 11%, and the Lean 5S tool was used to organize the mould exchange activities. An OEE of more than 90% has been achieved.

The transport of asphalt in countries where the temperature can be very low is necessary to be carried out in boxes provided with a coating, in order to reduce thermal losses. The temperature of the final mixed matter (asphalt bituminous with gravel) cannot significantly decrease during the transportation to the desired discharge site. The transport of asphalt from the production plant to the destination is carried out by proper vehicles. It is during this drive that the thermal loss is bigger. The evolution is constant both in vehicles and in freight boxes. In addition, the growing number of vehicles and roads paved with asphalt requires innovative solutions and improvements. This paper presents a novel concept of truck asphalt container attending to environmental concerns, comparing it to an earlier one. The load capacity of the vehicle was increased, the lifespan of the container was extended, the thermal losses were reduced and the number of travels regarding the same volume of asphalt was decreased. Thus, the fuel consumption of the empty vehicle was reduced. This Eco upgrade enables the transporter to be more competitive and environmentally friend.

The food industry is associated with high food standards and concerns that lead to a very competitive environment to which organizations respond with volume production strategies. These productions are ensured by advanced and complex equipment, which needs to be in optimal working conditions to meet the demands. Thus, unexpected failures leading to emergency stoppages in production and non-compliance with production plans should be avoided at all costs. This work consists in the development and application of a practical and structured method of equipment classification criticality based on its importance for the productive process, which culminated in the equipment classification into three categories (A, B and C). This method included five factors: Quality, Availability, Safety and Environment, Costs and Technological Complexity. It was applied to four different factories (a semolina factory, two pasta factories and a cookie factory) of a leading food group in Portugal. The classification of these assets into three categories allowed the definition of strategies for approach by category, which motivated the application of a methodology of Reliability Centered Maintenance (RCM), revision of Preventive Maintenance Plans (PMP), integration of critical asset in Computerized Maintenance Management System (CMMS) and many others. In order to validate the obtained results, an analysis and comparison of the results for the different factories under study were carried out.

The increasing competitiveness installed in the automotive industry implies continuous improvements in all fields of knowledge and action. Thus, it is very important to be aware of the wastes generate across all the productive and logistics operations. In this regard, and considering the production process of command cables for the automotive industry, it was detected that a significant volume of lubricant is wasted during the task of introducing grease into the spiral used in the command cables utilized to drive the doors, windows and brakes of motor vehicles. The industrial operation was carefully followed leading to identify the main causes of the wastes and a brainstorming was carried out allowing the discussion of new ideas on how to overcome the problem. A novel equipment was developed, being also cared all the logistics around the supplying task. The new solution developed, as well as the redefinition of the logistic process of supplying the lubricating grease to the production lines, made it possible to make the process more flexible for the admission of different grease packs, as well as a better utilization of the existing grease in the reservoirs, resulting in a cut of grease waste by more than 70%. It was also produced a prototype of the grease supply system, which allowed validate the previously developed system.

Adhesively-bonded joints are widely used to join structural components. The most common joint types are single-lap joints (SLJ), double-lap joints (DLJ), stepped-lap joints and scarf joints. Several factors influence the behaviour and strength of an adhesive joint, namely the type of adhesive (brittle or ductile, strong or weak) and joint geometry. One of the most important parameters that affects the joint strength is the overlap length (L O). A comparative study that involves several joint geometries and uses adhesives with different characteristics was carried out to check which type of adhesive is most suitable for a particular joint geometry. For this purpose, SLJ, DLJ, stepped-lap joints and scarf joints were chosen for testing with three adhesives. The experimental results were compared with numerical results obtained from Abaqus® using an integrated cohesive zone modelling module. Initially, a stress analysis was carried out to compare the different joint geometries. With this work, it was concluded that the optimal joint type significantly depends on the type of adhesive used, such that less strong and ductile adhesives are more suitable for joint geometries that exhibit large stress variations, while stronger but more brittle adhesives are recommended for joint geometries with more uniform stresses.

Pultrusion is a widely known technique for production of constant cross-section profiles, such as bars, L-shape or T-shape profiles, as well as structural tubes in polymer matrix composite materials. In some applications, requirements are demanding for profiles able to provide better thermal or sound insulation or needing a slightly higher moment of inertia without increasing the ratio between weight and strength. In such cases, hybrid pultruded profiles with core based on preforms are a possible solution. After obtaining prototypes according to the methodologies described in a previous work, and as a complement to that work, it is necessary to verify if the properties of these hybrid profiles correspond to the initial expectations, by performing destructive and non-destructive tests. Thus, tensile, compression and bending tests were performed, in order to verify the mechanical benefits achieved through the core introduction into the hollow profile and to analyse the added value brought by these new products. These values, once properly validated, can be added to existing databases related to structural calculation programs, enabling to get the adequate values for calculations regarding this kind of profiles. In addition, thermal and acoustic insulation tests were performed, in order to quantify the physical improvements achieved regarding these properties, which are extremely important in specific applications linked to the civil construction and public works, among many others. The cored profiles showed a strong adhesion between the profile and any kind of core tested as well as improved properties in terms of thermal insulation and moment of inertia. However, the sound insulation did not present significant improvements, probably due to GFRP profile external rigidity and consequent reflection.

Machining is a manufacturing process widely used in the industry that directly impacts on technological development. The machining processes are carried out by machine tools, which may have manual, automatic or CNC operation. The automatic machines are suitable for the production of parts with complex geometry and/or when it is necessary to produce parts on a large scale. In cases where there is a need to produce parts in large amounts, typically fully automatic CNC machines and processes are used, which increases the production capacity of the companies. These machines require equipment capable of feeding the raw material to the inside of the machine tools. For that, throughout this work is developed the mechanical design of a bar feeder machine for CNC turning centres, that will operate with low cycle time and can be operated safely and in a quick way by the operator.

High-strength composites are widely used in several industries, such as aeronautical, automotive and naval, and they can be combined with metals to provide significant advantages in structural design. The application of adhesive bonding to these assemblies supposes the existence of reliable design tools to accurately analyse the joints’ behaviour. In this context, the eXtended Finite Element Method (XFEM) is a recent possibility to predict bonded’ joints fracture behaviour. This work aims to study by XFEM single- L adhesive joints between aluminium components and carbon-epoxy composites under peeling loads, considering the variation of the L -shaped adherend’s thickness ( t P2 ) and adhesives of distinct ductility. The XFEM analysis was either based on stress or strain criteria for assessment of damage initiation, and different damage law types for crack propagation. Validation was undertaken with experimental data. The XFEM analysis revealed that this method is very accurate when using specific stress-based quadratic initiation criteria and the triangular propagation law. It was shown that the L -shaped adherend’s geometry and the adhesive type are the most important parameters affecting the joints’ strength.

The use of adhesive joints in industrial applications has been increasing in recent years because of the significant advantages offered compared to traditional joining methods such as welding, fastening and riveting. Thus, the existence of design tools is necessary to predict the joints’ strength with high accuracy. The eXtended Finite Element Method (XFEM) is emerging as a method to predict the joints’ behaviour, although this has not yet been adequately studied for the application to adhesive joints. This work presents an experimental and numerical study by XFEM of double-lap joints, in which adhesives ranging from brittle and strong, as the case of the Araldite® AV138, to more ductile adhesives, as the Araldite® 2015 and the Sikaforce® 7888, are applied. Aluminium substrates were considered (AW6082-T651) in joints with different overlap lengths (LO), subjected to a tensile load, in order to evaluate their performance. In the numerical study, an analysis of the stress distributions in the adhesive layer, a strength prediction by XFEM considering damage initiation criteria based on stresses and strains, and also a study on the energy criterion for damage propagation, were carried out. The XFEM analysis revealed that this method is very accurate when using specific damage initiation criteria, and a parameter of 1 in the damage propagation criterion, are considered. The choice of criteria that are not consistent with the adhesives’ behaviour and observed failure modes results in large errors.

Joining with structural adhesives in the aeronautical industry dates back to some decades, although only more recently this technique has been implemented to load bearing parts in other industries. This technique enables joining steel with aluminium or fibre-reinforced composites, with a major weight advantage. Cohesive Zone Models (CZM) are an accurate design method for bonded structures but, depending on the adhesive type and specimen's geometry, the accuracy of the strength predictions may be highly compromised by the choice of the cohesive laws. This work presents a validation of tensile and shear CZM laws of three adhesives obtained by the direct method applied to Double-Cantilever Beam (DCB) and End-Notched Flexure (ENF) tests, respectively. The validation is carried out by considering a mixed-mode bonded geometry (the single-lap joint) with different overlap lengths (LO) and adhesives of distinct ductility. Initially, the precise shape of the cohesive law in tension and shear of the adhesives is estimated, followed by their simplification to parameterized triangular, trapezoidal and linear-exponential CZM laws. Validation of the CZM laws was accomplished by direct comparison of the load-displacement (P-δ) curves and maximum load (Pm) of the single-lap joints as a function of the tested LO values. The strength predictions were accurate for a CZM law shape consistent with the adhesive type, although the differences between CZM shapes were not too significant.

Cohesive Zone Models (CZM) are widely used for the strength prediction of adhesive joints. Different simulation conditions, such as damage initiation and growth criteria, are available for use in CZM analyses to provide the mixed-mode behaviour. Thus, it is highly relevant to understand in detail their influence on the simulations’ outcome. This work studies the influence of different conditions used in CZM simulations to model a thin adhesive layer in single-lap joints (SLJ) under a tensile loading, for an estimation of their influence on the strength prediction under diverse geometrical and material conditions. Validation with experimental data is considered. Adhesives ranging from brittle to highly ductile and overlap lengths (LO) between 12.5 and 50 mm were considered. Different studies were considered: Variation of the elastic stiffness of the cohesive laws, different mesh refinements, study of the element type, and evaluation of several damage initiation and growth criteria. The analysis car...