3D Reinforcement Research Articles

Non-conformance aspects of moulded composite materials and “corresponding” simulation models with 3D textile reinforcement

Composite materials with 3-dimensional (3D) reinforcement were manufactured and corresponding simulation models were created in parallel. The used simulation approach has earlier been shown to produce close to authentic geometrical representation of the yarn architecture in 3D reinforcement. It is shown that although the as-woven reinforcement pattern can be modelled quite reliably, significant distortion from the nominal fibre arrangement might take place later in manufacturing, primarily related to compression during moulding. Such effects have earlier received significant attention for composites with 2-dimensional reinforcement but not as much for their 3D counterparts. The yarns in the real and the simulated materials are studied and compared, and some of the discrepancies and the mechanisms behind are discussed. The distortions are partly attributed to the relatively sparse weave that allows yarns oriented in the through-thickness direction, in particular, to deviate from their original positions.

Analytical assessment of pullout capacity of reinforcements in unsaturated soils

The effective interaction mechanisms in the pullout resistance of reinforcements include skin friction mobilized at the soil-solid surface, soil-soil shear resistance, and compressive resistance created against transverse elements. The third component is obtained from passive lateral pressure (LPM) or bearing capacity (BCM) methods. An analytical solution is proposed to determine the pullout capacity of geocell, geogrid, and strengthened geogrids embedded in ordinary and unsaturated soils. For unsaturated soils, the effective stress approach was employed. The solution-predicted results were compared with those obtained from large-scale pullout tests reported in the literature. Results indicated that considering LPM for 2D and 3D reinforcements better agrees with experimental results. The mobilized frictional rib-soil interfaces and the soil-soil shear resistance components generally contribute more to the pullout capacity of the geocell and geogrid, respectively. For the extensibility represented by mpi and flexibility of geocell denoted by αpi, the values of mpi = 1, 0.7, and 0.3 for the first, second, and third row of geocell, αpi= 0.4 for the first row of geocell and 0.25 for the second and subsequent rows are suggested to be considered. Parametric studies showed that the optimum transverse rib spacing is over 50 times the equivalent rib thickness (Beq).

3D FRP Reinforcement Systems for Concrete Beams: Innovation towards High Performance Concrete Structures.

Despite the advantages of using lightweight and non-corrosive carbon fiber reinforced polymer (CFRP) reinforcements in concrete structures, their widespread adoption has been limited due to concerns regarding the brittle failure of CFRP rupture and its relatively softer load-deflection stiffness. This work offers logical solutions to these two crucial problems: using aggregate coating to strengthen the CFRP-concrete bond and ultimately the load-deflection stiffness, and using CFRP-concrete debonding propagation to create pseudo-ductile behavior. Subsequently, the concrete cracking behavior, the apparent CFRP modulus with aggregates, and the post-peak capacity and deflection of three-dimensional (3D) CFRP-reinforced concrete are all described by equations derived from experiments. These formulas will be helpful in the future design of non-prismatic concrete components for low-impact building projects. The potential of this innovative design scheme in terms of increased capacity and deflections with less concrete material is demonstrated through comparisons between non-prismatic CFRP-reinforced concrete and measured steel reinforced equivalency.

Impact protection using novel fibre reinforced concrete

The research described in this paper identifies how the use of three-dimensional (3D) unwelded fibre reinforcement can provide protection against back-face spalling in the case of damage caused by impact, and contributes to understanding how such material specification can carry significant long-term benefits. When subjected to ballistic impact or explosion, reinforced concrete suffers back-face spalling caused by compressive stress waves, resulting in projectiles that can cause injury and collateral damage. This conceptual study seeks to reduce concrete projectiles and subsequent damage using 3D unwelded fibre-reinforcement. Conventional two-dimensional (2D) straight fibres rely on orientation and positioning for effective bridging of rupture planes, whereas 3D fibres benefit from inherent superiority of their orientation across a rupture plane. Twenty-five kilograms of 3D unwelded fibres (3DUWBL) and 2D fibres per m3 of concrete were used in the mix designs. Samples were tested for compressive strength, fibre pull-out, three-point and four-point flexural testing and ballistic impact. There was significant improvement in toughness and post-fracture control within the 3DUWBL specimens. The 3DUWBL fibres exceeded EN 14889 standards, outperforming the 2D fibre specimens, and controlled back-face spalling and reduced airborne projectiles in comparison to the 2D fibres. The study is limited to demonstrating proof of concept. The implication of these results will inform future research studies in this area. The results identify a current gap in research associated with 3D unwelded fibre use and the reduction of back-face spalling. 3D fibres overcome the significant failings of even dispersion and bond pull-out strength ordinarily associated with 2D fibres. This is due to the x y z orientation and omission of the welded connection. The implications are a reduction in manufacturing time and costs, making 3DUWBL fibres a more viable industry application. This research shows that 3D unwelded fibre reinforcement provides good resistance to back-face spalling of concrete elements when they are subjected to ballistic stresses. Such fibres are not currently commercially available, but they would be cheaper to produce, and their novel fibre shape provides enhanced post-crack toughness performance with the addition of lower variability, providing a lower-risk form of crack control.

New Approaches to 3D Non-Crimp Fabric Manufacturing

Textile reinforcements have outstanding load-bearing capabilities due to the excellent tensile properties of high performance multifilament yarns (e.g. carbon fibers). However, in order to take full advantage of their high potential, it is necessary to ensure that the filaments run in a straight line. In order to guarantee this straight filament course, the highly efficient multiaxial warp knitting process is used for the production of 2D non-crimp fabrics (NCF) as textile preforms. In various industrial applications, most structures have complex 3D geometries. Therefore, the 2D textile needs to be shaped for reinforcement, which often results in a rearrangement of the filament orientation. Consequently, the 3D shaping process has to be taken into account during the textile production or in the shaping process itself in order to guarantee the highest mechanical properties. Using the example of lattice girders for concrete reinforcement, a new approach for the fabrication of 3D textile lattice girders in a continous shaping process is presented. The results of the production tests of the developed technology approach show no apparent filament damage and exact roving orientation with no inadvertent deflection, compression or bulging, indicating a precise and gentle shaping process. The developed technology contributes to the future reduction of the production costs of 3D textile reinforcements.

A Hybrid Framework of Dual-Domain Signal Restoration and Multi-depth Feature Reinforcement for Low-Dose Lung CT Denoising.

Low-dose computer tomography (LDCT) has been widely used in medical diagnosis. Various denoising methods have been presented to remove noise in LDCT scans. However, existing methods cannot achieve satisfactory results due to the difficulties in (1) distinguishing the characteristics of structures, textures, and noise confused in the image domain, and (2) representing local details and global semantics in the hierarchical features. In this paper, we propose a novel denoising method consisting of (1) a 2D dual-domain restoration framework to reconstruct noise-free structure and texture signals separately, and (2) a 3D multi-depth reinforcement U-Net model to further recover image details with enhanced hierarchical features. In the 2D dual-domain restoration framework, the convolutional neural networks are adopted in both the image domain where the image structures are well preserved through the spatial continuity, and the sinogram domain where the textures and noise are separately represented by different wavelet coefficients and processed adaptively. In the 3D multi-depth reinforcement U-Net model, the hierarchical features from the 3D U-Net are enhanced by the cross-resolution attention module (CRAM) and dual-branch graph convolution module (DBGCM). The CRAM preserves local details by integrating adjacent low-level features with different resolutions, while the DBGCM enhances global semantics by building graphs for high-level features in intra-feature and inter-feature dimensions. Experimental results on the LUNA16 dataset and 2016 NIH-AAPM-Mayo Clinic LDCT Grand Challenge dataset illustrate the proposed method outperforms the state-of-the-art methods on removing noise from LDCT images with clear structures and textures, proving its potential in clinical practice.

Constituent components of 3D printing in construction: Mixture, reinforcement and their main characteristics

Construction 3D printing is one of the most promising areas in the construction of various structures. Thanks to the possibilities of automation, digital concrete production makes it possible to create complex structures that withstand the same forces as structures with standard geometry, but with increased structural efficiency and lower material consumption. This work is aimed at determining the main characteristics of mixtures for 3D printing and reinforcement strategies that are compatible with this technology. In addition, the article presents the results of a study of the strength characteristics of concrete used for 3D printing of building structures. The experiment was carried out by means of compression tests of concrete samples-cubes cut from the printed design with the dimensions of the rib 150, 100, 70 and 50 mm. This article can indicate the current state of affairs of 3D printing technology in construction, as well as indicate the direction of further research in this field.

Augmenting the mechanical performance of three‐dimensional woven composites by the synergistic effect of fabric architecture and interfacial interaction of carbon nanotubes

AbstractThree‐dimensional (3D) woven fabrics offer many advantages over planar woven fabrics for composite applications. Because of the complex structure of 3D woven fabrics, an in‐depth investigation is needed to understand the effects of fabric architecture and nanofillers on the mechanical and failure behavior of 3D woven composites. The present study investigates the effect of 3D woven ultrahigh‐molecular‐weight polyethylene (UHMWPE) orthogonal fabric architecture, with or without nanofillers, on the mechanical properties of composites. 3D woven orthogonal fabrics with varying proportions of stuffer‐to‐binder (S/B) yarns were manufactured and reinforced with an epoxy (EP) matrix. Multiwalled carbon nanotubes (MWCNTs) were infused as nanofillers to improve the interaction between the UHMWPE fabric and the EP matrix. 3D woven composite having an S/B ratio of 2:1 showed the maximum tensile strength and toughness. On the other hand, 3D woven composite with an S/B ratio of 4:1 showed higher flexural strength and impact resistance. The failure mechanism was also studied by examining the fractured surfaces of composites, which revealed matrix cracking, fiber pullout, predominant binder yarn failure, and yarn slippage. From this study, it is understood that for 3D fabric reinforcement, a balance between structural integrity and load‐bearing capacity of yarns is decisive, whereas for the matrix, the incorporation of MWCNTs is found to be advantageous.Highlights The role of structure of 3D woven orthogonal fabric on the mechanical behaviour of the UHMWPE‐epoxy composite is investigated. The addition of functionalized MWCNTs improves the tensile, flexural, and impact properties. The decisive role of the ratio of stuffer‐to‐binder yarns is established. Matrix cracking, debonding, and yarn failure are observed during tensile failure.

Effect of fillers and weave architecture hybridization on the impact performance of 3D woven hybrid green composites

AbstractThe eco‐friendly characteristics of green composites not only make them economically and technically viable but also contribute to the reduction of pollution. Green composites are developed by combining degradable fibers (primarily cellulosic materials) with natural resins. A disadvantage of green composites is their lower mechanical strength. To address this issue, 3D woven reinforcement along with fillers can be used to enhance the mechanical properties of green composites. In the current study, three different types of novel 3D woven hybrid structures, that is, hybrid through the thickness (HB‐1 (TT), novel woven layer‐to‐layer structure (HB‐2 (LL)), and layer‐to‐layer structure with double warp yarn (HB‐3 (LL)) were developed. Composites were fabricated using the compression molding technique. Three different concentrations (2%, 5%, and 8%) of nano clay (nanoparticles) were used as fillers and mixed in the green epoxy resin. Pendulum (Charpy) and drop weight impact tests of the composites were performed. The results showed that by the addition of nano particles the impact properties were increased. Nanoparticles showed a significant effect on impact strength. Charpy impact test results showed that the HB‐3 (LL) composite sample with 8% nanofillers showed the highest impact performance, while the HB‐1 (TT) composite sample with 8% nanofillers showed the highest impact performance during the drop weight impact test. By comparing the impact strength of the present work with that of similar research previously published, it is evident that our study achieved a remarkable improvement of 19.17%. This increase is due to the novel structures and nano fillers in the composite.Highlights Eco‐friendly green composites: economically feasible, minimizes pollution. Adding 3D woven structures to green composites improves their mechanical properties. Composite materials with nano clay fillers have increased impact resistance. The highest impact performance is shown by HB‐3 (LL) composites with 8% nanofillers.

Robot-Assisted Manufacturing Technology for 3D Non-Metallic Reinforcement Structures in the Construction Applications

Of all industrial sectors, the construction industry accounts for about 37% of carbon dioxide (CO2) emissions. This encompasses the complete life cycle of buildings, from the construction phase to service life to component disposal. The main source of emissions of climate-damaging greenhouse gases such as CO2, with a share of 9% of global emissions, is the production of ordinary cement as the main binder of concrete. The use of innovative approaches such as impregnated carbon yarns as non-corrosive reinforcement embedded in concrete has the potential to dramatically reduce the amount of concrete required in construction, since no excessive concrete cover is needed to protect against corrosion, as is the case with steel reinforcement. At the same time, architectural design options are expanded via this approach. This is achieved above all using novel robotic manufacturing technologies to enable no-cut direct fiber placement. This innovative technological approach to fabricating 2D and 3D biologically inspired textiles, including non-metallic structures for textile-reinforced concrete (TRC) components, will promote an automatable construction method that reduces greenhouse gas emissions. Furthermore, the impregnated yarn which is fabricated enables the production of load-adapted and gradual non-metallic reinforcement components. Novel and improved design strategies with innovative reinforcement patterns allow the full mechanical potential of TRC to be realized. The development of a robotic fabrication technology has gone beyond the state of the art to implement spatially branched, biologically inspired 3D non-metallic reinforcement structures. A combined robotic fabrication technology, based on the developed flexible 3D yarn-guiding and impregnation module and a 3D yarn fixation module, is required to implement this sophisticated approach to fabricate freely formed 3D non-metallic reinforcement structures. This paper presents an overview of the development process of the innovative technological concept.

Embroidered Carbon Reinforcement for Concrete

This research focuses on the manufacturing process and mechanical properties of textile reinforcements fabricated using embroidery technology. The study investigates both 2D and 3D reinforcement products and compares the advantages and possibilities of embroidery technology with other manufacturing methods. A series of tests using carbon reinforcement is conducted, and the results are presented and evaluated comprehensively. The uniaxial tensile tests reveal the characteristic behavior of carbon-reinforced concrete (CRC). Furthermore, the bonding behavior between the concrete matrix and embroidered carbon reinforcement is analyzed utilizing asymmetric pull-out tests, demonstrating that the embroidered reinforcements provide a sufficient bond. In addition to conventional 2D reinforcements, 3D reinforcements were also investigated, which can be efficiently manufactured using the TFP (tailored fiber placement) technology. Through the implementation of stirrup rovings, shear failure loads can be increased significantly. The results suggest that the mechanical properties of the reinforcement are influenced by the manufacturing process, which is particularly evident in the variation between longitudinal and transverse directions. The research highlights the potential benefits of using embroidery technology for textile reinforcement and indicates areas for further research and optimization in the manufacturing process. A pilot project that utilizes the embroidered reinforcement is currently under construction.

UAV-Net+: Effective and Energy-Efficient UAV Network Deployment for Extending Cell Tower Coverage With Dynamic Demands

Nowadays, mobile data traffic is growing explosively, but in many realistic scenarios, users still often encounter insufficient or unstable network bandwidth. A promising solution is provided by unmanned aerial vehicle mounted base stations (UAV-BSs) to serve regions with bandwidth shortfall. It is significant to investigate how to deploy UAVs effectively and efficiently for maximizing the sum throughput and service time of a set of mobile clients scattered in a large environment. A basic idea is to use RF ray tracing simulations as a hint to narrow down the search space of UAVs for conducting actual measurements. Furthermore, we formulate two key sub-problems, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">chunk selection</i> , which selects an optimal subset of chunks in the region as the search space of UAVs, and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">chunk search</i> , which plans the paths of UAVs to cover all selected chunks for conducting measurements, provide network services and charge timely under energy constraints to maximize the total service time. As they are both proved to be NP-hard, a 3D convolutional deep reinforcement learning (DRL) based chunk selection algorithm and an energy-aware DRL-based chunk search algorithm are proposed to solve them efficiently. A prototype system, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">UAV-Net+</i> , is implemented to evaluate the feasibility by conducting measurements by an UAV mounted WiFi AP communicating with several clients scattered in a campus, reporting an obvious throughput gain with a small measurement overhead and time consumption. Extensive simulations demonstrate the effectiveness of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3D convolutional DRL-based chunk selection algorithm</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">energy-aware DRL-based chunk search algorithm</i> . It is able to achieve 95.35% effective throughput of the skyline algorithm, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Oracle</i> , with only 0.7% time cost. It is more beneficial for providing long-time network service and balancing the workload among UAVs.

Heat treatment on the multiple-impact mechanical responses and damage behaviors of 3D and 2D woven GF/PP/epoxy composites

In this work, the 3D and 2D fabric reinforcements were made of glass/polypropylene (GF/PP) commingle filaments. The effect of heat treatment on the multiple impact mechanical responses and damage behaviors of GF/PP/epoxy composites were investigated. It is found that the pre-impact heat treatment (P) could maintain the best performance in the mechanical responses at the 3rd impact; The post-impact heat treatment (VH) could play the role of filler or healing agent after each impact load, but polypropylene fibers existing as reinforcement were melted into fusant and flowed out of the material along cracks, which results in reduction of mechanical properties. Under low-velocity impact, 3D woven composites were more sensitive to heat treatment because of the stress concentration of heated Z-binder yarns as the anti-delamination role; Perforation failure at the 3rd impact was found in the 3DOW structure with post-impact heat treatment, while the 2D woven laminated structure could still withstand more impacts. At high strain rates, heat treatment made polypropylene fibers be melted and recrystallized, and changed their volume and morphology, resulting in global micro voids in the material under impact load, which inhibits the formation of localized macro shear cracks.

Translaminar enveloping ply for CFRP interlaminar toughening

Developing low-cost and high-performance interlaminar toughening strategies for the advanced CFRP products has great engineering significances. Combining features on practical automated fiber placement and well-recognized 3D reinforcement technologies in the field of CFRP composites, herein, we alternately introduced a reinforcement ply in the manner of translaminar enveloping to generate interlocking and binding action into conventional lay-ups. Remarkably, more than 1700% for mode I (DCB) and 500% for mode Ⅱ (ELS) propagation fracture toughness improvements were experimentally investigated. The evolution of interlaminar toughening behaviors was specifically revealed. Multiple fracture energy absorption stages, successively including delamination tolerance, partial interface pull-out and through-thickness ruptures, reflect long-acting mode I toughening capacity. Under the multi-interface synergistic shear-delamination mechanism, the mode Ⅱ crack growth gets far more effectively suppressed. Meanwhile, the in-plane tensile and compressive strength could be maintained acceptably. We also gave insights into the technical superiorities of this original ply-level reinforcing work.

Tailoring strength-ductility of titanium matrix composites reinforced with graphene nanoplatelets

In this study, graphene nanoplatelets reinforced titanium matrix (GNPs/CT20) composites with adjustable performance were fabricated via 3D vibration milling and spark plasma sintering. With the progressive increase of GNPs, a quasi-continuous 3D reinforcement (TiC-GNPs-TiC) network was established and a peculiar phenomenon is observed that the ductility of GNPs/CT20 composites trends in hump type while the strength increases monotonically. The first crest of the humping ductility for GNPs/CT20 composites was attributed to the fine-grained CT20 matrix contributed by GNPs and in-situ generated TiC. Subsequently, the increasing TiC with discrete distribution dominated the tensile ductility behaviour which showed as the valley of humping ductility. Further additions of GNPs led to the network distribution of TiC-GNPs-TiC, which contributed to a relatively uniform deformation and the near equiaxed fine-grained microstructure gradually replacing the original Widmanstätten microstructure, thus promoting the second crest of the humping ductility. Finally, lots of TiC-GNPs-TiC further improved strength but inevitably reduced ductility for their serious agglomeration. This study focuses on the strengthening and toughening mechanisms of the quasi-continuous 3D TiC-GNPs-TiC network in titanium matrix reinforced by GNPs (TMCGs) and provides new insights into the design and fabrication of TMCGs with excellent strength-ductility.

Structural design and impact resistance of three‐dimensional structure‐reinforced flexible polymer composites

AbstractThree‐dimensional (3D) structure‐reinforced flexible polymer composites have great potential as personal protective materials. These composites exhibit excellent mechanical properties and failure mechanisms than typical rigid composites because of the complex dynamic reaction processes caused by the 3D structure in response to impact. This paper comprehensively reviews the impact resistance mechanism of 3D structure‐reinforced flexible polymer composites by combining current results with relevant investigations. 3D woven fabric reinforcements and flexible matrix materials of flexible polymer composites systems are presented in this paper. The classification for 3D woven fabric reinforcements is reviewed, as well as the effect of reinforcement structures on the impact resistance of the flexible composites. Furthermore, several flexible matrix are introduced. Several external factors affecting the impact resistance of composites are then discussed. Finally, the impact damage mechanism of 3D structure‐reinforced flexible polymer composites is summarized and analyzed.

Comparison of Embankment Reinforcement Requirements with Geotextile on Soft Soil with 2D and 3D Slope Stability Analysis Methods

Slope stability analysis is very important in slope design so it can manage and maintain the infrastructure assets. If the slope is unstable, it can damage the infrastructure around the slope. The method commonly used in slope stability analysis is 2D modeling which assumes the length of the landslide area is not limited or continuous. In fact, landslides that occur in the field are limited and not continuous, so 3D modeling is more suitable than 2D modeling. 3D slope stability analysis has been developed by various researchers. Most of the results of previous studies stated that the 3D and 2D factor of safety ratio was more than one for cohesive soils and less than one for non-cohesive soils. This safety factor affects the amount of reinforcement needed. Differences in 2D and 3D safety factors will cause differences in the amount of reinforcement needed. Therefore, this study was conducted to determine the differences in the 2D and 3D slope stability analysis result. Slope stability analysis was carried out using LEM, where the 2D slope stability used the Fellenius method while the 3D slope stability used the Hovland method. Calculate the required reinforcement amount using geotextiles with Tult = 250 kN/m. The results obtained from this study are the 2D safety factor is smaller than the 3D safety factor. The 3D and 2D safety factor ratios range from 1.09 – 1.397. While the amount of reinforcement required in the 3D analysis is less than in the 2D analysis with the ratio of 3D and 2D reinforcement requirements ranging from 0.5 to 0.955 depending on the width and height of the embankment.

Textile-Based 3D Truss Reinforcement for Cement-Based Composites Subjected to Impact Loading Part I: Development of Reinforcing Structure and Composite Characterization

Concrete is extremely vulnerable against impact loading due to its low tensile strength and pronounced brittleness. The application of thin strengthening layers, containing Textile Reinforced Concrete (TRC) and Strain-Hardening Cement-based Composites (SHCCs) in a ductile cement-based composite, is a promising solution to enhance the impact resistance of existing concrete structures. Three-dimensional (3D) textile structures exhibit numerous advantages over two-dimensional (2D) ones, most importantly higher shear, bending and energy absorption capacity, hence, appear to be instrumental in providing sufficient reinforcement to the target strengthening layers. However, design variability and optimization possibility of available 3D textile reinforcement are restricted. This paper presents the development of novel textile-based 3D truss reinforcement that can overcome these limitations. On the basis of woven 3D cellular structures, innovative pyramidal 3D truss reinforcement with favorable load-bearing capacity as well as notable energy absorption capability is developed and successfully realized. To investigate the feasibility and efficacy, cement-based composite consisting SHCC and newly developed pyramidal 3D truss reinforcement is prepared and tested under high-speed tensile loading as well as transversal impact loading. The experimental results show that woven 3D truss reinforcement is highly compatible with SHCC, and significantly enhances its impact resistance. Furthermore, SHCC reinforced with novel pyramidal 3D truss structure remarkably outperforms that with 2D carbon reinforcing structure approved for commercial use.

Biologically Inspiried Load Adapted 3D Textile Reinforcement Structures

A significant strategy to reduce the demand for natural resources and the associated environmental impact is enhanced material efficiency in the design process for new building structures. Innovative concepts for designing, modelling, constructing, producing and utilising sustainable resource-efficient concrete-based building components will be the foundation for future-oriented constructions. For this reason, the ability to process biologically inspired 3D textile reinforcement structures is crucial to fully exploit the potential of carbon concrete. This research project provides a fundamentally realigned, CAE-supported approach so that optimization algorithms, numerical models for the generation of robot placement paths and bionically induced yarn positioning can be taken into account. The evolved intelligent and modular yarn placement system forms the basis to overcome current challenges involved in the placing and stabilizing of spatial and highly branched reinforcement topologies during the manufacturing process. Hence, the novel tool-independent, geometrically highly variable, robot-supported fibre placement technology is supposed to be capable of manufacturing biologically inspired load adapted 3D textile topologies with reinforcement in z-direction.

Impact Performance of Three-dimensional Woven Composites with Novel Binding Yarn Patterns

ABSTRACT This research offered an experimental examination of the effect of binder yarns, and 3D woven patterns on impact (Charpy and drop weight impact), and compression after impact (CAI) performance of seven (07) different kinds of 3D woven jute/green epoxy composites. Along with four (04) typical classifications of 3D woven reinforcements i.e., OLL, OTT, ALL, ATT, and three (03) novel (hybrid) 3D reinforcements i.e., H1 (OTT and ATT interlocking pattern), H2 (OTT and ALL interlocking pattern), H3 (OLL warp and weft interlocks “bidirectional”) were also developed on dobby weaving machine. OTT composite displayed the highest amount of impact strength during Charpy impact in both in-plane directions i.e., warp and weft in comparison with others due to the existence of the truly vertical binder yarns which is comparable with H1. While ALL sample exhibited the highest value of maximum load, work done, and energy absorbed during the 3 J and 6 J drop weight impact energies which is nearest comparable with hybrid 3 (H3) composite. H3 composite sample revealed the highest value of compression after impact (CAI) stress and modulus in both energy levels due to the presence of both warp and weft binder yarns in a single 3D structure.