Manufacturing Of Composite Parts Research Articles

Experimental substantiation of the technology for manufacturing composite parts based on a viscous metal-polymer

ABSTRACT The article deals with an experimental study of the technological process of obtaining a composite ABS, a metal-polymer part. As the title implies the article describes a method and device for the manufacture of composite parts based on the method of vacuum suction of a viscous metal-polymer into a shell form. Recommendations are given on the technological modes of filling the mould, taking into account the presence of vibration in the process of filling the mould with a metal-polymer, as well as the Reynolds number parameter for establishing a laminar flow of the metal-polymer in the technological mould cavities. The study of the strength of the designed composite part has been carried out using the finite element method of the APM FEM module. The calculations of the strength and stiffness of parts made of ABS, metal-polymer and metal make it possible to compare the strength characteristics of parts made by various methods. Relevant recommendations are given on the use of a composite part reinforced with a metal-polymer in the field of mechanical engineering.

Towards Advancing Translators’ Guidance for Organisations Tackling Innovation Challenges in Manufacturing within an Industry 5.0 Context

Following the vision of the European Commission, organisations and workers establishing Industry 5.0 approaches aspire to more future-proof, resilient, sustainable, and human-centred European industries. In this contribution, we explore how technological innovations that contribute to a “win–win” interaction with involved stakeholders may be advanced in a human-centred and transparent proceeding supported by impartial expert translators who provide information or knowledge-based guidance for decision-makers, initiators and implementers in manufacturing innovation driven by sustainability. We elaborate a stepwise procedure for agreeing on milestones and conjointly treading the path towards solving innovation challenges during a translation process. We exemplify the technological aspects of such a process using an innovation case aiming at identifying parameters for enhancements in a vacuum-bagging process applied to the manufacturing of composite parts from prepregs based on condensation-curing matrix resins made from renewable resources. In detail, we present a straightforward design of an experimental approach varying the dwelling temperature and the temperature ramps during the curing of stacked prepregs. In this way, we demonstrate that for cured composites comprising a poly(furfuryl alcohol)-based matrix, the porosity and connected mechanical properties achieved with autoclave-free curing processes sensitively depend on these process parameters. Applying the resulting data-based model is shown to support decision-making for sustainable composite manufacture.

Continuous tow shearing for the automated manufacture of defect-free complex 3D geometry composite parts

It has always been challenging to manufacture a composite structure with complex geometry using automated fibre placement (AFP) process. The tool surface is difficult to be tessellated using fibre tapes with a finite width, without producing gaps and overlaps, and fibre steering along non-geodesic fibre paths produces various defects such as tape buckling and pull-up. In this work, a defect-free fibre-steering process on a complex surface was demonstrated by realising the continuous tow shearing (CTS) process in three dimensions. A new head control algorithm was developed, which defines the head orientations and trajectories based on the pin-jointed net model to manipulate the fibre tow using both in-plane shear and out-of-plane twisting deformations. Fibre steering process utilising this new algorithm was tested on a doubly-curved surface, using an industrial robot arm equipped with a CTS prototype head, and its layup quality and accuracy were assessed by using a three-dimensional laser profile scanner. An experimental comparison with the conventional AFP process showed that the new control algorithm enables defect-free fibre steering on complex 3D surfaces allowing for simplifying the design and analysis of novel composite structures.

An anisotropic topology optimization procedure for continuous fiber reinforced polymer structures with biaxial fiber layout for improved intersection point design

Fiber placement technologies allow for manufacturing of complex-shaped composite parts with load-adapted fiber orientation. For design of corresponding structures, topology optimization is well-established. However, anisotropic topology optimization approaches are often limited to unidirectional fiber orientations. In truss-like topology optimized structures, the intersections between the individual trusses are subject to multiaxial stress states. For those, a unidirectional fiber orientation is not appropriate and may not be suitable for manufacturing.In this work we propose a topology optimization procedure that allows for unidirectional but also biaxial fiber orientations. The choice between unidirectional and biaxial fiber layout is based on the stress state within the finite elements. For the biaxial fiber layout, the first fiber angle is aligned with the maximum absolute principal stress direction, while the second fiber orientation is calculated using composite net theory.Results show that considering biaxial fiber orientations leads to fiber orientations that can be better manufactured by fiber placement technologies and are considered suitable for automatic derivation of manufacturing-tolerant placement paths. Furthermore, the stress state at intersections is improved reducing the probability of inter fiber failure. In addition, consideration of biaxial fiber orientations could increase the stiffness at constant weight compared to purely unidirectional topology optimization.

A microwave resonance thin-film sensor for real-time wireless temperature monitoring in composites manufacturing

Composites are of growing importance to today's industries. Curing or consolidation under certain temperatures is a vital process to manufacture composite parts. Great attention has been paid to monitoring the temperature of composite parts being processed. Wireless monitoring methods are extensively explored for their unique advantages in realizing real-time monitoring of specific temperature distribution of the part. Here, a flexible microwave resonance sensor is first introduced to achieve real-time wireless temperature monitoring of composites. When applied to curing processes with different heating rates, it was found that the sensing relationship of the sensor was varied. Through in-depth analysis, the relationship between peak frequencies and temperature was established with consideration of different heating rates. In several curing processes with different heating rates, the mean error of the thin film sensor using a heating rate-related relationship was about 4.23 °C. which can be reduced by more than 43 % compared with the method using a static relationship.

A sequential inverse approach for draping simulations of woven fabrics with anisotropic hyperelastic behavior laws

Simulations of the draping of woven fabrics for the manufacturing of composite parts with complex geometries rely on either the geometrical method, which does not consider the shearing stresses and the external forces, or incremental finite element analyses, which require substantial CPU times. In this study, the one-step finite element method, also referred as the inverse approach in the literature, commonly used for sheet metal forming, is adapted to the woven fabric draping. The main issue of one-step simulations is the convergence of the Newton–Raphson scheme, which relies on an appropriate initial solution estimation. This problem is addressed by a sequential initial solution estimation, based on successive sub-problems with increasing difficulty up to the actual one. Applications of the proposed method on elementary test cases show fast and robust convergence, with CPU times comparable to those of the geometrical method. The proposed method is able to predict the influence of external forces and material hyperelastic mechanical behavior laws on the strain components of interest of woven fabrics, such as the shearing angles between yarns and the yarn elongations.

Stochastic semi-analytical modeling of reinforced filaments for additive manufacturing

This study presents a novel stochastic modeling approach that addresses two challenges encountered in micromechanical modeling of short-fiber composites. Firstly, the challenge of the time-consuming pre-processing required for extracting fibers from micro CT scans is tackled by introducing a new stochastic generation technique based on the kernel density estimation (KDE) method. This enables the generation of artificial fibers for micromechanical models, thus saving considerable time and effort. Secondly, the challenge of presenting a modeling approach that considers multiple fibers while reducing the computational effort associated with the simulation is addressed through a novel semi-analytical approach. To demonstrate the effectiveness of the stochastic modeling approach, it is applied to filaments of recycled poly(ethylene terephthalate) reinforced with recycled short carbon fibers that are used for additive manufacturing of composite parts. The results obtained from the stochastic modeling approach are compared with those from a direct modeling approach that considers 1050 fibers extracted from a micro CT scan. The novel approach is shown to provide similar predictions of elastic properties as the direct modeling approach while using only 40–50 fibers. Furthermore, the results are in close agreement with experimental data, highlighting the effectiveness of the proposed approach.

Toyota cuts manufacturing costs with Zortrax 3D printers

How Toyota in Poland uses 3D printers to manufacture composite parts, improving workflow and the supply chain.

Recycled Glass Polypropylene Composites from Transportation Manufacturing Waste

In recent years there has been growing interest in developing recycling technologies for composites manufacturing scrap, process waste and end-of-life parts. The focus of this work was to establish processing routes and mechanical property bounds for glass-polypropylene (PP-GF) scrap from the production of parts for truck trailers, automobiles, and rail cars. This study considered PP-GF scrap and demonstrated extrusion-compression molding (ECM) as a viable route for the closed-loop manufacture of composite parts. The results were promising in terms of the strength and modulus retention of the PP-GF recyclate. The tensile strength and modulus was the highest for 50% and 66% recycled content, compared with 100% and 83% recycle content. The flexural strength and modulus of the 100% and 83% recycled compositions was higher than the 66% and 50% recycled content, respectively. The impact energy absorption of the PP-GF recyclate at at all fiber loadings was superior in absorbing energy compared with the incumbent (benchmark) plywood. This work is useful to designers seeking to incorporate recycled materials in their products.

Simulation Analysis of Stress Field of Walnut Shell Composite Powder in Laser Additive Manufacturing Forming

A calculation model of stress field in laser additive manufacturing of walnut shell composite powder (walnut shell/Co-PES powder) was established. The DFLUX subroutine was used to implement the moveable application of a double ellipsoid heat source by considering the mechanical properties varying with temperature. The stress field was simulated by the sequential coupling method, and the experimental results were in good accordance with the simulation results. In addition, the distribution and variation of stress and strain field were obtained in the process of laser additive manufacturing of walnut shell composite powder. The displacement of laser additive manufacturing walnut shell composite parts gradually decreased with increasing preheating temperature, decreasing laser power and increasing scanning speed. During the cooling process, the displacement of laser additive manufacturing of walnut shell composite parts gradually increased with the increasing preheating temperature, decreasing scanning speed and increasing laser power.

Basic design and technological solutions for the application of automated layout processes in the manufacturing of composite parts of passenger aircraft

Currently, there are great perspectives for the technology of manufacturing products and aggregates from PCM based on prepregs. Thus, the use of prepregs makes it possible to manufacture complex configuration parts in one technological operation. High competition and the increasing necessity of mass production of large-sized parts from PCM determines the emerging need for the use of automated layout equipment. The replacement of traditional, manual methods of layout by automated methods provides significant advantages, such as an increase in the quality of the resulting parts, a significant reduction in labor intensity of their production, an increase in accuracy and repeatability of the technological process of layout (reduction of defects) and, consequently, reduction of the cost of the finished product.

СОВРЕМЕННЫЕ МЕТОДЫ ПРИ РЕМОНТЕ И ВОССТАНОВЛЕНИИ ДЕТАЛЕЙ МАШИН ДЛЯ ПОВЫШЕНИЯ ЭФФЕКТИВНОСТИ ТРАНСПОРТНО-ДОРОЖНОГО КОМПЛЕКСА

An experimental study of the technological process of obtaining a composite ABS - a metal-polymer part is considered. A method and device for the manufacture of composite parts based on the method of vacuum suction of a viscous metal polymer into a shell form are described. Recommendations are given on the technological modes of filling the mold, taking into account the presence of vibration in the process of filling the mold with a metal polymer, as well as the Reynolds number parameter for establishing a laminar flow of the metal polymer in the technological mold cavities. The study of the strength of the designed composite part was carried out using the finite element method of the APM FEM module. The calculations of the strength and stiffness of parts made of ABS, metal-polymer and metal made it possible to compare the strength characteristics of parts made by various methods. Relevant recommendations are given on the use of a composite part reinforced with a metal-polymer in the field of mechanical engineering.

Applicability assessment of thermoset coating onto additively manufactured thermoplastic composite molds

Coatings can significantly enhance the surface characteristics of printed molds however, there is no guideline to assess the coating applicability for additively manufactured fiber-reinforced thermoplastic molds. Therefore, the applicability of a thermoset polymer surface coating onto additively manufactured carbon fiber-reinforced Polyphenylene Sulfide (CF-PPS) composite mold was investigated. The coating application temperature should not be higher than the maximum operable temperature of the substrate. Therefore, Dynamic Mechanical Analysis (DMA) of the printed CF-PPS was performed to characterize the dependence of the elastic modulus on temperature as well as to verify the thermal stability of the printed molds at the coating processing temperature. The cure kinetics of the coating material was characterized to guide the design of processing conditions to achieve a complete cure of the thermoset resin. The composite mold needs to withstand multiple thermal cycles for the part manufacturing process. Thermal degradation of the coating was assessed for multiple thermal cycles utilizing Thermogravimetric Analysis (TGA) and the results did not show significant degradation. To provide insights into the coefficient of thermal expansion (CTE) mismatch between the coating and the printed CF-PPS, the CTE was characterized for both material systems. Additionally, the coating adhesion was characterized via pull-off tests after multiple thermal cycles and the results revealed no significant change in the pull-off strength after ten cycles. Finally, the coating was demonstrated on a mold printed with CF-PPS which was subjected to multiple autoclave composite part manufacturing cycles. The durability of the coating and the geometrical deviation of the mold were investigated throughout the manufacturing cycles.

Gate‐to‐Gate Study for Collaborative Robot‐Assisted Composite Parts Manufacturing Using a Work Effort Unit Approach

AbstractThis work presents one example from a set of technologies that aim at improving the efficiency of manufacturing processes of aircraft components in one of Airbus Defence and Space plants in regards to environmental aspects. Among the proposed technologies, one relates to the automation of two key manufacturing steps of the reference technology in the composite manufacturing of omega stringers: 1) lamination of main omega stringer structure through an Automated Fiber Placement robotic process; and 2) cobotic pick‐and‐place process for Carbon Fiber Reinforced Polymer patches. To evaluate potential environmental benefits, Fraunhofer performs a gate‐to‐gate study using as main parameter the “Work effort unit,” in this case representing the average energy consumption per productive hour in a typical assembly factory. When comparing the results for the composite part manufacturing by hand lay‐up with the use of collaborative robots, the key technical parameter is the reduction in lead time. While production using robots consume additional electricity when compared to human workers, automation significantly shortens lead times (‐74%), resulting in lower energy consumption per manufactured unit. The results indicate that this new technology from Airbus Defence and Space can potentially improve the overall environmental performance of composite parts during their manufacture.

What is the economic feasibility of manufacturing a metal-metal- polymer composite part compared to other technologies?

ABSTRACT The purpose of the article is to analyse the manufacturing factors that affect the cost of manufacturing a part. Nowadays the cost of equipment used for metal 3D printing, as well as metal powders, are still very expensive. The cost of additive manufacturing of metal parts is mainly dependent on the volume of printing, therefore, reducing the volume of printing can lead to a significant reduction in the cost of manufacturing the part. Manufacturing of a metal shell, the cavity of which is filled with a cheap metal polymer, can be an excellent alternative to an all-metal part. The article provides a method for calculating the cost of manufacturing a lever part using various technologies: subtractive, additive, and composite part manufacturing technology. According to the calculated data, the dependence of the cost of manufacturing a part on piece time has been built, which can be interpreted as the amount of machining. The constructed linear dependence can give an idea of the effectiveness of the application of a particular technology for obtaining a part. In addition, non-economic factors affecting the possibility of using various technological processes for manufacturing a part are described.

Reactive Processing of Acrylic-Based Thermoplastic Composites: A Mini-Review

The demand for thermoplastic composites is continuously increasing because these materials offer many advantages over their thermoset counterparts, such as high toughness, long storage time, easy repairing and recycling, and ability to be thermoformed and heat-welded. However, the manufacturing of thermoplastic composite parts using liquid composite moulding techniques (e.g. resin transfer moulding, vacuum assisted resin transfer moulding … ) is often tricky in the case of melt processing where high temperature and pressure should be chosen to impregnate the fibre reinforcement because of the high melt viscosity of thermoplastics. These issues may be overcome by means of reactive processing where a fibrous preform is first impregnated by a low viscosity mono- or oligomeric precursor and the polymerization of the thermoplastic matrix then occurs in-situ. This article draws a state of the art on the manufacturing characteristics of continuous fibre reinforced acrylic-based reactive thermoplastics (e.g. polymethymethacrylate (PMMA) such as Elium®), which are becoming more and more popular compared to other fast curing thermosets and thermoplastics for in-situ polymerization. Techniques for the in-situ polymerization of methymethacrylate monomers, characterization and modelling of the rheological properties and polymerization kinetics, and some manufacturing related issues such as polymerization shrinkage are reviewed. Particular features of the use of reactive PMMA in different manufacturing techniques of continuous fibre reinforced composites and potential industrial applications are also introduced. Finally, some perspectives for the academic research and industrial development are proposed.

ОЦЕНКА ЭКОНОМИЧЕСКОЙ ЭФФЕКТИВНОСТИ ТЕХНОЛОГИИ ИЗГОТОВЛЕНИЯ КОМПОЗИТНЫХ МЕТАЛЛ-МЕТАЛЛОПОЛИМЕРНЫХ ДЕТАЛЕЙ В СРАВНЕНИИ С АДДИТИВНОЙ И СУБТРАКТИВНОЙ ТЕХНОЛОГИЯМИ

The development of additive manufacturing leads to the emergence of new 3D printing technologies, new materials for 3D printing and a gradual reduction in the cost of production. Nowadays, the cost of equipment used for metal and metal powders 3D printing are still very expensive. This factor makes the production technologies unavailable for the civil engineering industry in the manufacture of functional parts. The cost of additive manufacturing of metal parts is mainly dependent on the volume of printing. Reducing the print volume can lead to a significant reduction in the cost of manufacturing the part. Fabrication of a metal shell, the cavity of which is filled with a cheap metal polymer, can be an excellent alternative to an all-metal part. Such a metal-metal-polymer composite part can have sufficient strength and significantly lower cost. However, there are no dependencies today to understand the economic efficiency of using a particular production technology. The article provides a method for calculating the cost of manufacturing a lever part using various technologies: subtractive, additive and composite part manufacturing technology. According to the calculated data, the dependence of the cost of manufacturing a part on piece time is built. It can be interpreted as the amount of machining. The constructed linear dependence can give an idea of the effectiveness of the application of a particular technology for obtaining a part. In addition, non-economic factors affecting the possibility of using various technological processes for manufacturing a part are described. Together, the presented data allow the technologist to comprehensively assess the possibility of effective application of a particular production technology and make an appropriate informed decision.

Concurrent topology and fiber orientation optimization method for fiber-reinforced composites based on composite additive manufacturing

Additive manufacturing of fiber-reinforced composite (FRC) parts provides a new rapid prototyping technique for designs. However, restricted by the layer-by-layer style of additive manufacturing techniques, the designed fiber orientations should be parallel to the print plane, and that will result in a reduced design space for the orientation optimization. To enlarge the orientation design space under this constraint, this paper proposes a new optimization method for FRC parts. The optimized structure is composed of several groups of components, and the fiber orientation of each group of components is constrained to a specific plane. Based on the composite additive manufacturing technology, these components can be fabricated separately and joined together to form the whole structure. The number of the component groups (also the fiber print planes) is predefined. In this method, the structure is optimized by concurrently designing the topology, the components partitioning and the fiber orientations. The structural topology and components partitioning are described by the SIMP interpolation scheme and discrete material optimization (DMO) interpolation scheme, respectively. The discrete-continuous parameterization (DCP) method with two sub-intervals is applied in the orientation optimization to avoid the local optimum of the angle variables, and a unified formulation is given for the concurrent optimization design. Furthermore, a density projection strategy with self-adaptive threshold parameters for multi-material optimization problems is proposed to get the distinct component interfaces. A stable convergence can be obtained without manually adjusting the projection parameters during the optimization iterations. The corresponding angle filtering method is developed to smooth the optimized fiber orientations. Numerical examples and manufacturing experiments are presented to demonstrate the effectiveness of the proposed method.

Effect of process parameters on AA6061/Q345 bimetal composite for hot stamping

Hot stamping is an advanced forming process used in automobile lightweight manufacturing, but it has not been used in the manufacture of bimetal composite parts. In this work, based on the hot stamping forming technology and the advantages of bimetal composite in strength, stiffness and corrosion resistance, the finite element simulation theoretical analysis and test on the hot stamping forming of AA6061/Q345 bimetal composite U-shaped parts were performed. The effect of initial temperature, stamping speed, die gap and pressure holding time on forming quality were investigated. The results show that the initial temperature not only affects the temperature distribution of each layer of the bimetal composite after stamping but also affects the deformation resistance during forming. The increasing stamping speed reduces the contact time between the die and plate rising the plate temperature, but the increasing stamping speed also strengthens the stamping hardening effect in the forming process leading to the stress increase. The die gap affects the contact area between the plate and the die. The increasing gap is beneficial to reduce the temperature difference between different layers. However, an excessive die gap also increases the tensile stress in the plate and affects the forming accuracy. With the pressure holding time larger, the temperature of the formed part becomes low, the residual stress releasing causes the stress to be smaller. According to the analysis of tensile and bending mechanical properties, it is indicated that the formed parts prepared by the optimal parameters obtained by numerical simulations have excellent mechanical properties and formability.

Large-Scale Robot-Based Polymer and Composite Additive Manufacturing: Failure Modes and Thermal Simulation.

Additive manufacturing (AM) of large-scale polymer and composite parts using robotic arms integrated with extruders has received significant attention in recent years. Despite the contributions of great technical progress and material development towards optimizing this manufacturing method, different failure modes observed in the final printed products have hindered its application in producing large engineering structures used in aerospace and automotive industries. We report failure modes in a variety of printed polymer and composite parts, including fuel tanks and car bumpers. Delamination and warpage observed in these parts originate mostly from thermal gradients and residual stresses accumulated during material deposition and cooling. Because printing large structures requires expensive resources, process simulation to recognize the possible failure modes can significantly lower the manufacturing cost. In this regard, accurate prediction of temperature distribution using thermal simulations is the first step. Finite element analysis (FEA) was used for process simulation of large-scale robotic AM. The important steps of the simulation are presented, and the challenges related to the modeling are recognized and discussed in detail. The numerical results showed reasonable agreement with the temperature data measured by an infrared camera. While in small-scale extrusion AM, the cooling time to the glassy state is less than 1 s, in large-scale AM, the cooling time is around two orders of magnitudes longer.