Properties Of Fibrous Materials Research Articles

Data driven statistical method for the multiscale characterization and modelling of fiber reinforced composites

Multiscale analysis of composite laminates allows for predicting the mechanical response of these materials avoiding cumbersome experimental campaigns. The matrix and fibre material properties and the size of the Representative Volume Element (RVE) are the main parameters affecting the accuracy of multiscale models. This paper proposes a statistical inverse method to calibrate micromechanical material parameters from macroscale experiments and 3D reconstruction. First, glass fiber reinforced epoxy laminates have been analysed with Computer Tomography (CT), then, the material 3D microstructure has been reconstructed and fibre, matrix, and voids were segmented. Tensile tests have been performed on the composite specimen, measuring the surface strains with a Digital Image Correlation (DIC) system. The reconstructed volume, converted to a voxel mesh, has been used to compute the homogenized response of composite by Fast Fourier Transform (FFT) analysis. By comparing the marginal distribution of homogenized material stiffness extracted from DIC data of tensile tests, with the conditioned distribution computed by varying the FFT model parameter, a Stochastic Volume Element (SVE) is finally calibrated. A probabilistic multiscale model based on the SVE that propagates the uncertainty from the microscale to the structure level is presented.

Recent Advances in Ballistic Resistance of Lightweight Metal Sandwich Cores

Sandwich construction has proven to be an excellent low-density multifunctional design for a wide range of applications in ballistic protection, energy absorption, and thermal insulation. Based on the bulletproof effect of each layer of the sandwich structure, this paper expounds and summarizes the material properties that can be used as each layer. The mechanical and ballistic properties of ultra-high strength aramid (Kevlar) and ultra-high molecular weight polyethylene (UHMEPE) composites and the ballistic properties of mixed fibers of these two materials versus the mechanical properties of single fiber materials, the mechanical properties, chemical stability and other properties of aluminum and magnesium alloys, the effects of heat treatment and coating treatment on the ballistic properties of aluminum alloys, and finally the energy absorption properties of several common core materials structures are compared.

Stability analysis of hybrid laminated cylindrical shells reinforced with shape memory fibers

Laminated composite structures are widely used in various industries. Body and cape of high-speed flight vehicles are exposed to aerodynamic heating so that causes thermal buckling and dynamic instability. Shape memory alloys (SMAs) have extraordinary mechanical and physical properties which made them suitable for application in laminated structures. In this paper, stability analysis of hybrid laminated cylindrical shells reinforced with SMA fibers is investigated. Utilizing the principle of virtual displacement, governing equations and associated boundary conditions are determined based on the first-order shear deformation theory of shells considering Von- Kármán form of geometrical non-linearity and Love's first approximation. Material properties of SMA fibers and composite vary due to temperature. Variation of thermo-mechanical properties for SMA fibers due to uniform change of temperature are determined through the one-dimensional form of Brinson's constitutive law. Also, different types of loading conditions consist of axial load, pure lateral pressure and hydrostatic pressure are considered. Eventually, the effect of material properties, boundary supports and temperature on the critical buckling axial load, pure lateral pressure and hydrostatic pressure of the laminated cylindrical shells are studied. Investigations indicate that volume fraction and pre-strain of SMA fibers have significant effect on the stability of the laminated cylindrical shells.

An overview of mechanical properties of biodegradable polymers and natural fibre materials

In this review paper, we discussed about bio-degradable polymer composition materials with low cost, less weight and eco-friendly comparing to synthetic materials. These bio-degradable materials are the answer to reducing environmental pollution and also improving soil fertility when they decompose. Most of the polymer materials are polysaccharides, poly lactic acid etc and natural fibers materials are sisal, hemp, husk etc. These materials have good mechanical properties and it is equal to the other artificial polymers and fibers. Due to their promising properties and functionality, research on these composites is expected to increase along with the implementation of new composite systems in the future. The methods of mechanical test varied widely, and the conditions under which mechanical properties degraded varied as well.

Mechanical properties of CFRP bar with different elevated-temperature experiences

Material properties of carbon fiber reinforced polymer (CFRP) at elevated temperatures are of great importance to promote its application in civil engineering. Previous literatures focused mainly on steady-state temperature tests, neglecting the thermal experiences that CFRP may undergo in real fire scenarios. To address this gap, it conducted four types of tensile tests on CFRP bars to simulate different elevated-temperature experiences ranging from 25 to 300 °C. This study investigated properties of CFRP under tensile tests at room temperature and steady-state tests, as well as properties at elevated temperatures with sustained load and after exposure to elevated temperatures. The tests showed that CFRP bars without sustained load remain about 85%, 75%, and 52% of their original strength at 100 °C, 150 °C and 300 °C, after 0.5 h thermal experience, respectively. In addition, the ultimate stress decreased by 11% when heating duration increased from 0.5 h to an hour and thereafter remained stable at 300 °C. Meanwhile, the CFRP bars with sustained load (stress level of 0.3) at 300 °C presented a 7% reduction of tensile strength compared to those without sustained load. For the CFRP bars exposed to 300 °C for an hour and cooled naturally to room temperature, the tensile strength and modulus decreased by 17% and 5%, respectively, but remained higher than those tested at 300 °C due to the solidification of softened resin. This investigation provides insights into the behavior at elevated temperature of CFRP.

Effects of multiple post cure cycles on properties of composite carbon fibre and epoxy materials

Post-curing cycles have an effective impact on the thermal and mechanical properties of thermoset composite materials. Typically, post-cure cycles use heat to expose cured resin parts to high temperatures in an attempt to maximize their final properties. In most cases, these processes allow composite parts to achieve the highest possible strength and become stable. In industrial practice, however, it has been found that there are potential consequences of performing localized repairs on composite parts in an autoclave where the localized repair undergoes a normal curing process while the parent part undergoes an additional curing process. Thus, for the parent part, prolonged exposure to high temperatures can trigger a process of decomposition of the resin matrix, as could be the aging phenomena of composites in service. In such a scenario, two practical questions are worth asking: (1) to what extent can a resin matrix be post cured without risking degrading its thermal properties? (2) what are the residual mechanical and physical properties resulting from prolonged exposure of composite parts to elevated temperatures? In this work, an analysis was carried out to estimate the potential adverse effects on thermoset composite parts made of carbon fibre and epoxy resin materials commonly used in aerospace, in terms of thermal, physical and mechanical properties after a long exposure to high temperatures caused by multiple post cure cycles. Two types of prepreg laminates were used to make monolithic test panels using twill and plain weave architectures for the M21 and 8552 test panels respectively. Thermal tests were conducted to evaluate the evolution of the degree of cure, the glass transition temperature and the inter-laminar shear strength of post-cured panels, which were subjected to a different number of post cure cycles. The study found that multiple post cure cycles alter thermal properties, which in turn have adverse effects on physical and mechanical properties. The results demonstrated that the two types of composite materials respond differently to changes in properties. Twill weave panels quickly reach full cure after three stages while plain weave panels have undergone gradual curing. This difference in the curing process of the resin matrix clearly influenced the changes in the measurements of shear, surface hardness and compressive strengths.

Prediction of compressive strength fiber-reinforced geopolymer concrete (FRGC) using gene expression programming (GEP)

This paper examines the rapidly evolving fiber-reinforced geopolymer composites (FRGC), focusing on the material and geometrical properties of construction fibers and the mechanisms involved in fiber-binder interaction at different curing conditions to determine the compressive strength. To eliminate expensive and time-consuming experimental techniques, soft computing techniques, i.e., gene expression programming (GEP), were used to develop an empirical equation for the prediction of compressive strength (fc′) of FRGC. The database consists of 393 experimental datasets to determine the (fc′) with several curing days to train the GEP models. The mixtures contain the most influential parameters such as fly ash (FA), silica fume (SF), metakaolin (MK), ground granulated blast furnace slag (GGBS), aggregate (AG), sodium hydroxide (SH), sodium metasilicate (SM), alkaline activator (AAK), binder (B), superplasticizer (SP), water (W), curing age (CA), length (L), diameter (D), aspect ratio (AR), density (ρ), tensile strength (ft′), and fiber (F) to determine the fc′. The database is separated into two parts, 70% is used for training, and 30% is for testing. Several linking functions, chromosomes, head size, and genes have been undertaken to determine the optimal results. Expression trees (ETs) are developed and presented in the discussion section, and create the empirical equation from it. Determining the performance of the best model, MSE, RMSE, and R2 are calculated for the FRGC mixture to confirm the GEP models under various situations. Additionally, sensitivity analysis (SA) is also introduced to see the FRGC of each input parameter’s contribution to the prediction of fc′.

Experimental investigation of carbon long fiber reinforced polyamide 6 exposed to environmental conditions

AbstractTo enhance the possibilities in lightweight constructions in terms of processability and recyclability, fiber reinforced thermoplastics are a promising class of materials. In this context, the fiber‐matrix interface has a major influence on the mechanical properties of the composite. With polyamide 6 (PA6) being a hygroscopic thermoplastic, the effects of elevated humidity and temperature on the mechanical behavior must be considered [1]. This study aims to characterize the micro‐mechanical material properties of carbon long fiber reinforced PA6 in quasi‐static tensile tests after exposure to elevated temperature and humidity levels. Therefore, the specimens are conditioned in different climates and tested afterwards. In order to determine the initiation and propagation of matrix cracks, interface failure, and fiber fracture, the experiments are conducted on a micro‐scale with an average cross‐section of 0.03 mm2. The damage patterns are captured using optical microscopy and SEM images. The effects of conditioning at various temperature and humidity levels are discussed. The main results are the qualitative description of the degradation of mechanical properties due to hydrothermal effects.

Development of an Active Optical Lens for Arc Flashing Detection.

This paper contains the design of active optical lenses used for the detection of arc flashing emissions. The phenomenon of an arc flashing emission and its characteristics were contemplated. Methods of preventing these emissions in electric power systems were discussed as well. The article also includes a comparison of commercially available detectors. An analysis of the material properties of fluorescent optical fiber UV-VIS-detecting sensors constitutes a major part of the paper. The main purpose of the work was to make an active lens using photoluminescent materials, which can convert ultraviolet radiation into visible light. As part of the work, active lenses with materials such as Poly(methyl 2-methylpropenoate) (PMMA) and phosphate glass doped with lanthanides, such as terbium (Tb3+) and europium (Eu3+) ions, were analyzed. These lenses were used to make optical sensors, which were supported by commercially available sensors in their construction.

Analysis of Thermomechanical Behavior of the Tubular Braided Fabrics with Flax/Polyamide Commingled Yarns.

Flax fibers are widely used as the strongest natural fibers in composite parts with advanced structures. Due to their excellent mechanical properties and recyclability, they have attracted more attention from the aviation and automotive industries, etc. These composite parts are usually obtained by preforming reinforcements or prepregs at high temperatures, and their mechanical behaviors are greatly affected by temperature variations. To improve the understanding of the mechanical properties of flax fiber materials, especially for the braided fabric with non-orthogonal structures, uniaxial tensile tests at different temperatures and tensile speeds were conducted on hollow tubular braided fabrics. The thermomechanical properties of Flax/Polyamide12 (PA12) prepregs were analyzed. The results show that temperature and tensile speed have obvious effects on the strength and shear stiffness of tubular fabrics. The strength and shear stiffness of the fabric decreases as the ambient temperature increases. Meanwhile, the strength of the fabric can also be improved by appropriately increasing the tensile speed. In addition, according to the experimental results, a theoretical model is established to describe the shear angle on the smallest circumference of the fabric, which provides a theoretical basis for the subsequent simulation process. The test results can provide a reference for the manufacture of flax fiber-reinforced composites with tubular structures.

Effects of Hybrid Rockwool–Wood Fiber on the Performance of Asbestos-Free Brake Friction Composites

The present study explores the physical-mechanical and tribological properties of hybrid wood fiber and rockwool-reinforced asbestos-free resin-based friction materials. We developed asbestos-free brake friction composites with different contents of hybrid fiber (wood and rockwool fiber) at a total fixed fiber loading of 30%. Then, the developed composites were investigated on the physical, mechanical, and tribological properties according to the industry standards. The results show that, with the increase in wood fiber, the density, hardness, and strength decrease, and the water absorption increases. Meanwhile, rockwool fiber can improve the coefficient of friction and enhance friction stability, while wood fiber has a significant impact on wear resistance. The sample with 5% wood fiber and 25% rockwool fiber presented the best performance in terms of the coefficients of friction, wear rate, and fade–recovery behavior. It provides a new idea for the research of asbestos-free composites.

Kinetics of water sorption in single Sterculia and Bauhinia fibers at ambient temperature

Fundamental study on material properties of lignocellulose fiber is important to understand the performance of composite materials. In this study, we explored several material properties of untreated, commercial and wood ash alkali retted fiber obtained from relatively less studied and traditionally important wild plant species Sterculia villosa (local name Murgilo or Mudilo) and Bauhinia vahlii fibers (local name Bharlo). Water sorption kinetics in all fiber types was measured at ambient temperature. Fickian model then was used to fit experimental sorption kinetic data and information on diffusion coefficients at early and late stages of sorption, average diffusion coefficient, sorption coefficient, and water permeability were obtained. The average diffusion coefficient (D) for untreated, wood ash alkali and commercial alkali treated Sterculia was found to be 10.6 × 10-13 m2/sec, 3.08 × 10-12 m2/sec, and 2.35 × 10-12 m2/sec; respectively. The corresponding values for Bauhinia fiber were found to be 6.8 × 10-13 m2/sec, 3.80 × 10-12 m2/sec, and 3.46 × 10-12 m2/sec; respectively. The equilibrium water sorption in the alkali treated fiber was significantly reduced due to removal of cementing materials and also increase of crystallinity. Significant decrease in mechanical strength of fiber in sorbed state was found. These findings will be useful to understand stability of fiber and potential end products such as paper sheets and reinforced composite materials exposed under different moisture conditions.

Tailor-made novel electrospun polycaprolactone/polyethyleneimine fiber membranes for laccase immobilization: An all-in-one material to biodegrade textile dyes and phenolic compounds

In spite of many works on the biodegradation of textile dyes and phenolic compounds, we propose a new, inexpensive, environmentally friendly, and sustainable material based on electrospun fiber and immobilized laccase. The polycaprolactone (PCL)/polyethyleneimine (PEI) electrospun fibers were optimized and prepared by electrospinning technique according to the operational parameters like PCL concentration (12 wt%), PEI concentration (10 wt%), voltage (16 kV), needle tip-collector distance (20 cm), and injection speed (0.7 mL/h). Next, characterization studies were performed to investigate the morphology and structure of the electrospun fibers without and with laccase. The crude laccase was obtained by cultivating the white rot fungus T. trogii (TT), and T. versicolor (TV). The resulting electrospun fibers showed a smooth surface with a mean diameter of around 560 nm, and larger diameters were observed after laccase immobilization. According to the results, immobilization increased the stability properties of laccase such as storage, and operational. For instance, the residual activity of the PCL/PEI/TTL and PCL/PEI/TVL after 10 repeated cycles, was 33.2 ± 0.2% and 26.0 ± 0.9%, respectively. After 3 weeks of storage, they retained around 30% of their original activity. Moreover, the PCL/PEI/TTL and PCL/PEI/TVL were found to possess high decolorization yield to remove Orange II and Malachite Green textile dyes from solutions imitating polluted waters. Among them, the PCL/PEI/TTL exhibited the highest decolorization efficiencies of Orange II and Malachite Green after 8 continuous uses at pH 5 and a temperature of 50 °C, reaching over 86%, and 46%, respectively. Moreover, PCL/PEI/TTL and PCL/PEI/TVL effectively degraded the 2,6-dichlorophenol phenolic compound at an optimal pH and temperature range and exhibited maximum removal efficiency of 52.6 ± 0.1% and 64.5 ± 7.6%, respectively. Our approach combines the advantageous properties of electrospun fiber material and immobilization strategy for the efficient use of industrial scale important enzymes such as laccase in various enzymatic applications.

Predicting the elasto-plastic response of short fiber reinforced composites using a computationally efficient multi-scale framework based on physical matrix properties

Predicting the nonlinear mechanical response of short fiber reinforced composites (SFRCs) is a crucial and challenging task. In this paper, a computationally efficient multi-scale strategy is proposed to predict the anisotropic elasto-plastic behavior of SFRCs using the intrinsic mechanical behavior of the pure polymer and fibers without the requirements for reverse engineering. In doing so, different simple unit cells are first examined to find the one that can adequately describe the nonlinear mechanical response of SFRCs' representative volume elements (RVE) with aligned fibers. Considering the effects of packing configuration, fiber aspect ratio, volume fraction and material properties, the performance of different unit cells is investigated. Then, the homogenized mechanical responses of unit cells are linked to Hill's anisotropic plasticity model to correlate the mechanical response of the suggested unit cell to the continuum domain. Using the pseudo-grain approach and a numerical orientation averaging framework, the effects of fiber misalignment are taken into account. A multi-step homogenization strategy is also employed to consider the variation of fiber orientation tensor and volume fraction through the thickness. Finally, the validity and robustness of the proposed multi-scale strategy are extensively investigated based on the RVE-generated results and the available experimental observations.

EFFECT OF CERTAIN CATALYTIC POISONS ON THE ACTIVITY OF CUPRUM-PALADIUM COMPLEXES APPLIED ON CARBON MATERIAL IN THE REACTION IN THE REACTION OF CARBON MONOXIDE OXIDATION BY AIR OXYGEN

Oxide and metal complex catalysts for low temperature gas-phase oxidation of carbon monoxide by air oxygen lose their activity under the action of chemical poisons such as SO2, H2S, PH3, H2O. We have developed a highly efficient Wacker-type catalyst in which the carrier is a carbon fiber material (CFM), the precursor of which was cellulose hydrate. For such a catalyst, there are no studies on the effect of catalytic poisons, namely SO2 and H2O, on its activity in the reaction of low-temperature oxidation of CO with oxygen. The morphology, elemental composition and adsorption properties of carbon fiber material and carbon monoxide oxidation catalyst are investigated. Pd(II)-Cu(II)/CFM relative to water vapor and sulfur dioxide, as well as their effect on the protective properties of the catalyst. SEM studies (scanning electron microscope) confirmed the morphology typical of CFM and found very small agglomerates in the case of the catalyst, which are formed by paratacamite Cu2(OH)3Cl crystallites caused by oxidation of the carbon surface by palladium (II). When applying the catalyst components, the fibers do not lose their shape, but the surface of the fibers is unevenly covered with impurities. Palladium (II) is reduced by a carbon surface by about 10%, agglomerates [Pdo]n are not observed, while fiber erosion increases and very small agglomerates are formed on the surface, which are formed by Cu2(OH)3Cl phase crystallites. Carbon material is generally characterized by a high content of carbon and oxygen, but their distribution is heterogeneous. In the analysis of adsorption isotherms, which are classified as type IV, it was found that CFM and the catalyst based on it belong to the microporous samples. It is proved that only at the relative humidity of the gas-air mixture, which is equal to 30% C < MPCSO2 (20 mg/m3). Catalyst poisoning does not disrupt the catalytic process, but with increasing amount of absorbed sulfur dioxide (QSO2 ) the degree of conversion of carbon monoxide decreases and especially sharply at the absorption of 10.3⋅10–4 mol SO2. Thus, the results obtained on the effect of relative humidity and the amount of adsorbed by the catalyst SO2 on the activity of Pd(II)-Cu(II)/CFM catalyst, indicate a significant reduction in the degree of conversion of carbon monoxide. Therefore, in the case of applying of such a catalyst, for example in respiratory protection against CO, a preliminary stage of absorption of moisture and sulfur dioxide should be provided.

Movement of flexible filter media under pulse-jet filter cleaning conditions

Reverse pulse-jet cleaned bag filters are widely used for the removal of fine particles from gas streams. Based on the material properties of a single fiber, the entire filter medium is modeled which shows an elastic and apparent viscous property mainly due to the restoration of the weaving pattern. Thus, for the pulse-jet cleaning, the actual transient pressure difference can be linked directly to the deflection of the filter medium. The filter medium displacement is simulated for the filtration and cleaning measures by finite element method (FEM) for a clamped filter test sample and the large-scale bag filter situation, respectively. As expected a high curvature of the filter medium coincides with a high equivalent tensile stress which in turn is a pre-curser for the probability for cake breakage.

On correlation of stamping process with fiber angle variation and structural performance of thermoplastic composites

This study aims to experimentally explore the influences of stamping conditions on the variations in fiber yarn angle and material properties of continuous fiber reinforced thermoplastics (CoFRTP). First, the upright-orthogonal (O-), biased-orthogonal (B-) and non-orthogonal (N-) specimens were manufactured with thermo-stamping process. Second, the X-ray computed tomography (CT) was employed to characterize fiber yarn angle variations within each layer of thin-walled CoFRTP structures nondestructively. The results indicate that fiber yarn angle varied in different layers at the same position and also changed at different positions in the same layer for the N-specimens. In addition, the 6-ply, 8-ply and 10-ply N-specimens exhibited a similar average variation in fiber yarn angle. Finally, the tensile and three-point bending (TPB) tests were conducted to investigate the effects of stacking sequence and fiber yarn angle variations on material properties and structural performances of these consolidated CoFRTP specimens. In the off-axis tensile tests, the modulus, yield strength and failure strength of laminates decreased but the failure strain increased with increasing fiber yarn angle. In the TPB tests, the O-specimen showed the smallest failure displacement, the B-specimen presented the highest peak force, and the N-specimen exhibited the largest failure displacement. This study is anticipated to gain insights into the relationship between stamping process and forming characteristics as well as structural performances of CoFRTP structures.

Wave dispersion characteristics of laminated carbon fiber reinforced polymer composite shells resting on viscoelastic foundations under thermal field

Wave dispersion characteristics of laminated composite shells resting on viscoelastic foundations in thermal environments are examined. Three types of temperature distributions (i.e., uniform, linear, and sinusoidal) along the thickness of the laminates are considered. Effective material properties of the carbon fiber reinforced polymer (CFRP) composite are calculated by the Mori-Tanaka homogenization method. The four-variable higher-order shear deformation theory (HSDT) and Hamilton principle are utilized to derive the equations of motion. The Navier approach in conjunction with wave solution is exploited to obtain the dispersion relations of the simply supported laminated shells with cross-ply and antisymmetric angle-ply arrangements. A comparative study is performed to demonstrate the validity of the present model. A parametric study is conducted with focus on the effects of curvature ratio, viscoelastic foundation parameters, carbon fiber volume fraction, number of layers, lamination scheme, temperature distribution, temperature difference, and fiber orientation on the wave dispersion behavior. Numerical results manifest that uniform temperature distribution reduces the phase velocity furthest. At low wave number, the extrema of phase velocity are determined by the curvature ratio and fiber orientation. The results can be used for the ultrasound detection techniques and structural health monitoring.

Appearance and conductivity of weft-knitted unibody positioning flexible sensor

PurposeThe purpose of this research is to propose a flexible sensor with a weft-knitted float stitch structure and to explore knitting techniques that allow conductive yarns to be skin-tight and less exposed, reducing production processes and increasing productivity. Study its electrical conductivity in different yarn materials, knit processes and deformation ranges. The analysis is compared to provide some basis for the design of the electrodes.Design/methodology/approachThe method includes five operations: (1) Analysis of the morphological appearance, tensile variation, fiber material properties and electrical conductivity of high-elastic and filament silver-plated conductive yarns. (2) Based on the knitting process of the floating yarn structure, three-dimensional modeling of the flexible sensor was carried out to explore the influence of knitting process changes on appearance characteristics. (3) The fabric samples are knitted by different silver-plated conductive yarns with different structures. Processing of experimental samples to finished size by advance shrinkage. (4) Measure the resistance of the experimental sample after the machine has been lowered and after pre-shrinking. Use the stretching machine to simulate a wearing experiment and measure the change in resistance of the sample in the 0–15% stretching range. (5) Analyze the influence factors on the conductive performance of the flexible sensor to determine whether it is suitable for textile flexible sensors.FindingsFor the float knitted flexible sensors, the floating wire projection is influenced by the elasticity of the fabric and the length of the floating wire. Compared to the plain knitted flexible sensors, it has less resistance variation and better electrical properties, making it suitable for making electrodes for textile structures. In addition, the knitting method is integrated with the intelligent monitoring clothing, which saves the process for the integration of the flexible sensor, realizes positioning and fixed-point knitting.Practical implicationsThe sensor technology of the designed weft-knitted float structure is varied and can be freely combined and designed in a wide range. Within the good electrical conductivity, the flexible sensor can realize integrated knitting, positioning monitoring, integrating into the appearance of clothing. It can also focus on the wearing experience of wearable products so that the appearance of the monitoring clothing is close to the clothes we wear in our daily life.Originality/valueIn this paper, an integrated positioning knitting flexible sensor based on the weft knitting float structure is studied. The improved knitting process allows the sensing contact surface to be close to the skin and reduces the integration process. The relationship between the exposure of the silver-plated yarn on the clothing surface and the electrical conductivity is analyzed. Within a certain conductive performance, reduces the exposed area of the conductive yarn on the clothing surface and proposes a design reference for the flexible sensor appearance.

Correlated evolution between orb weaver glue droplets and supporting fibres maintains their distinct biomechanical roles inadhesion.

Orb weaving spiders employ a ‘silken toolkit’ to accomplish a range of tasks, including retaining prey that strike their webs. This is accomplished by a viscous capture spiral thread that features tiny glue droplets, supported by a pair of elastic flagelliform fibres. Each droplet contains a glycoprotein core responsible for adhesion. However, prey retention relies on the integrated performance of multiple glue droplets and their supporting fibres, with previous studies demonstrating that a suspension bridge forms, whose biomechanics sum the adhesive forces of multiple droplets while dissipating the energy of the struggling insect. While the interdependence of the droplet's glycoprotein and flagelliform fibres for functional adhesion is acknowledged, there has been no direct test of this hypothesized linkage between the material properties of each component. Spider mass, which differs greatly across orb weaving species, also has the potential to affect flagelliform fibre and glycoprotein material properties. Previous studies have linked spider mass to capture thread performance but have not examined the relationship between spider mass and thread material properties. We extend earlier studies to examine these relationships in 16 orb weaving species using phylogenetic generalized least squares. This analysis revealed that glycoprotein stiffness (elastic modulus) was correlated with flagelliform fibre stiffness, and that spider mass was related to the glycoprotein volume, flagelliform fibre cross‐sectional area and droplets per unit thread length. By shaping the elastic moduli of glycoprotein adhesive and flagelliform fibres, natural selection has maintained the biomechanical integration of this adhesive system.