Effect Of Gauge Length Research Articles

Material characterization of coconut midrib strip - a sustainable material for ground improvement

The tensile behavior of soil is of utmost importance in civil engineering as tensile failure can cause cracking earthen dam construction and road pavement subgrade. To address this issue, natural fiber reinforced geotextiles are increasingly being utilized in various geotechnical applications. This study aims to investigate the effect of gauge length, strain rate, and Young's modulus of a single coconut midrib taken from a leaf by conducting a series of uni-axial tensile strength tests. Additionally, the characteristic tensile strength is determined using Weibull statistical distribution analysis to evaluate the consistency of test results. Overall, this article contributes to a better understanding of the tensile behavior of natural fiber reinforced geotextiles and can aid in the design and construction of geotechnical structures that are resistant to tensile failure. According to the study's findings, an increase in gauge length and strain rate led to a decrease in the Weibull modulus. Moreover, for larger gauge lengths and strain rates, inconsistent variations in the coefficient of variation were observed. The experiments also showed that midribs immersed in water for seven days exhibited lower tensile strength, and consistent outcomes were obtained when using a gauge length of 150 mm and a strain rate of 0.3%/min. These results contribute to a better understanding of the factors that affect the tensile behavior of coconut midribs, particularly when used in geotechnical applications, and can inform the selection of appropriate testing parameters for future studies.

Rate-dependent tensile behavior and statistic strength model for fiber tow composites

The mechanical performance of the fiber tow composite is crucial for textile composites. To characterize the tensile properties of the carbon fiber tow composite, a tensile test methodology for high strain rate loading was developed based on the Split Hopkinson tensile bar equipped with an ultra-high-speed camera. The tensile performance of the tow composites is measured under quasi-static and dynamic loading rates, respectively. Furthermore, the effects of gauge length, fiber counts of specimens and the strain rate sensitivity are investigated. The results indicate that the tensile strength of carbon fiber tow composite is related to the length and fiber counts of the tow specimen and affected by the loading rates. In addition, a modified Weibull model was proposed to evaluate the effects of gauge length and strain rate on the tensile strength of the carbon fiber tow composites.

Effect of gauge length on the mechanical responses and crystallization behavior of poly(glycolide-co-caprolactone) (PGCL) suture

Effect of gauge length on the mechanical responses and crystallization behavior of poly(glycolide-co-caprolactone) (PGCL) suture

Appropriate software model for evaluating the effect of untreated and treated sisal fibre with different gauge length and strain rates for geotextile applications

Geotextiles are commonly used as reinforcement in building, engineering and road laying applications. The sisal fibre is one of the natural fibres which is used to reinforce soil and prevent damage. This sisal fibre is specifically helpful to fill gaps between roads to improve soil structure, and prevent soil erosion but allows the water to drain off. This paper is concerned with the study of the effect of gauge length on the strength and elongation of sisal fibres in untreated and treated states with sodium hydroxide at different concentrations and duration of treatment. The reason for applying sodium hydroxide treatment on sisal fibre is to remove the impurities from it and to improve the inter fibre adhesion with resin for producing a composite. The effective reinforcement of composites with plant fibres depends on the moisture content and the fibre matrix interfacial adhesion. Treatment with alkali improves the performance of fibres when they are used as composites. Also, the effect of strain rate on the strength and elongation of sisal in untreated and treated states has been investigated. The Weibull modelling software model has been used in many studies to quantify the degree of variability in the fibres. This paper deals with the application of an appropriate software model such as the Weibull distribution model for quantifying the variability in strength and elongation at different gauge lengths varied from 10 mm to 100 mm and also varied the strain rate from 10 mm/min to 500 mm/min. In addition to the Weibull distribution model, air plasma treatment and SEM (Scanning Electron Microscope) analysis on sisal fibre were also carried out in this paper. The result shows that the sisal fibre is more suitable for geotextile applications.

Environmental Effects on Strength and Failure Strain Distributions of Sheep Wool Fibers.

Sheep wool is an eco-friendly, renewable, and totally recyclable material increasingly used in textiles, filters, insulation, and building materials. Recently, wool fibers have become good alternatives for reinforcement of polymer composites and filaments for 3D printing. Wool fibers are susceptible to environmental degradation that could shorten their lifetime and limit applications. This study reports on the mechanical properties of sheep wool fibers under the impact of humid air and UV irradiation. The results of single fiber tensile tests showed a noticeable gauge length effect on the fibers’ strength and failure strain. Long (50 mm) fibers possessed about 40% lower characteristics than short (10 mm) fibers. Environmental aging decreased the elastic modulus and strength of the fibers. Moisture-saturated fibers possessed up to 43% lower characteristics, while UV aging resulted in up to a twofold reduction of the strength. The most severe degradation effect is observed under the coupled influence of UVs and moisture. The two-parameter Weibull distribution was applied for the fiber strength and failure strain statistical assessment. The model well predicted the gauge length effects. Moisture-saturated and UV-aged fibers were characterized by less extensive strength dependences on the fiber length. The strength and failure strain distributions of aged fibers were horizontally shifted to lower values. The results will contribute to be reliable predictions of the environmental durability of sheep wool fibers and will extend their use in technical applications.

Modeling the effect of gauge length on the mechanical properties of Chitin Whiskers reinforced composites

Mechanical properties (tensile strength and modulus) of Chitin Whiskers fibre-reinforced poly(acrylic acid) with different fibre loading and different gauge lengths are compared with theories of reinforcement. The addition of random oriented Chitin Whiskers to poly(acrylic acid) matrix increased in tensile strength and elastic modulus of the composite. There was a steady increase in tensile stress and Elastic modulus within the volume fraction range investigated. The properties of the composite at different gauge lengths were studied. Within the same volume fraction, the tensile stress decreases as the gauge length increases. It is the reverse for the Elastic Modulus. Irrespective of filler loading and the theoretical modelling equations the tensile stress can be predicted at 40 mm gauge length. For the Elastic Modulus, the prediction of the property varies within the gauge lengths investigated. At higher filler loading, a smaller gauge length is required to predict the Elastic modulus. The comparative study between the tensile stresses obtained by experiment and selected theoretical models showed that the Parallel and Series models of the Rule of Mixture produced more accurate prediction, followed by Halpin-Tsai and modified Halpin-Tsai models. Guth's model was the least as the percentage deviation from the experimental data was very high when predicting the Elastic modulus. The density of the nanocomposite films were 1.08g/cm3, 1.023, and 1.024g/cm3 respectively, for 3%, 6%, and 9% weight filler and were in agreement with the theoretical data.

Tensile and fracture behavior of silica fibers from the Venus flower basket (Euplectella aspergillum)

The extraordinary mechanical properties shown by many biological materials stem from their unique hierarchical structures. The spicules of the deep-sea glass sponge, Euplectella aspergillum, show layered architecture and are known to improve toughness in various loading conditions. In the present work, we conducted a systematic study on the tensile and fracture behavior of E. aspergillum’s spicules. Tensile tests were performed on three different gage lengths of spicules that compose anchoring structures of E. aspergillum. The cross-sectional area of each spicule was accurately measured using an x-ray microscope. The effect of gage length and varying cross-sectional area on the tensile behavior of spicules is discussed in detail. The interplay between two failure initiation sites, namely, weakest-link flaws and minimum cross-sectional area locations was observed. Weibull statistics were used to quantify the variability in the strengths of spicules as a function of their gage length. The Weibull modulus was observed to decrease with the increase in gage length. The possibility of a bimodal flaw population for a higher gage length of spicules due to the interplay between failure initiation sites is also discussed. The fractography study was utilized to understand the failure and toughening mechanisms of spicules in tensile loading. The fracture toughness of the central core was quantified from fracture surfaces using a linear elastic fracture mechanics model. The present study shows that the failure of spicules initiates in the outer layers and proceeds progressively to the center. The layers surrounding the central core of the spicule resist the crack propagation and increase its toughness.

The seismic wavefield as seen by distributed acoustic sensing arrays: local, regional and teleseismic sources.

Distributed acoustic sensing (DAS) exploiting fibre optic cables provides high-density sampling of the seismic wavefield. Scattered returns from multiple laser pulses provide local averages of strain rate over a finite gauge length. The nature of the signal depends on the orientation of the cable with respect to the passing seismic waves. For local events, the dominant part of the strain rate can be extracted from the difference of ground velocity resolved along the fibre at the ends of the gauge interval. For more distant events the response at seismic frequencies can be represented as the acceleration along the fibre modulated by the wave slowness resolved in the same direction, which means there is a strong dependence on cable orientation. Slowness–frequency representations of the wavefield provide insight, via modelling, into the character of the DAS wavefield in a range of situations from a local jump source, through a regional earthquake to teleseismic recording. The slowness-domain representation of the DAS signal allows analysis of the array response of cable configurations indicating a bias due to the slowness weighting associated with the effect of gauge length. Unlike seismometer arrays the response is not described by a single generic stacking function.

Effect of Chopped Sisal fiber (CSF) on enhancing the compressive strength of Local Plaster of Paris (LPOP)

An attempt has been made in the current work to study the influence of using one of the natural fibers (which is: The Sisal Fiber (SF)) on enhancing the compressive strength of Local Plaster of Paris (LPOP). The research plan involves studying the effect of gage length of the chopped SF (CSF) (precisely:10 mm and 30 mm) and also the effect of the weighted content of CSF (1% and 2%). The experimental work involves casting five mixtures (of three cubic (5 × 5 × 5)cm specimens each). Four of these mixtures contain CSF with different gage lengths and weighted contents, and the fifth mixture is the reference one (free from CSF). The (Water/Plaster) ratio for all those mixes were fixed at (0.5). It was found that, the addition of CSF leaded to an improvement in the compressive strength of LPOP for both weighted contents and gage lengths, and the optimum content was (1%) for both gage lengths (10 mm and 30 mm). Furthermore, it was also found that, the compressive strength of LPOP is improved when the gage length of LPOP is increased from (10 mm) to (30 mm).

Measurement and Analysis of Heterogeneous Strain Fields in Uniaxial Tensile Tests for Boron Steel Under Hot Stamping Conditions

BackgroundA significant amount of uniaxial tensile tests has been carried out using Gleeble systems to investigate the viscoplastic deformation of boron steel (22MnB5) under hot stamping conditions. However, due to heat loss through the end clamps, a temperature gradient in the reduced parallel section of dog-bone shaped specimens is inevitable.ObjectiveIn the work reported in this paper, the effect of temperature gradient on measured outcomes is examined.MethodsUniaxial tensile tests on 1.5 mm thick boron steel specimens are carried out, under hot stamping conditions and strain fields are quantified using the digital image correlation (DIC) technique. The effect of gauge length on the properties of boron steel, as calculated from observed test results, is determined.ResultsCompared with the test at room temperature, a bell-shaped strain distribution occurs within the gauge length even before the appearance of the maximum load. Also, average strain within the gauge length, especially in the later stages, changes with gauge length within the investigated range, and thus, different engineering stress-strain curves and fracture strains are determined. In addition, normalized strain rate is significantly dependent on gauge length, which results in over 16% difference among the computed flow stresses by using a unified constitutive model.ConclusionsThe characterized properties of the material are dependent on gauge length and thus, a testing standard for measuring thermal-mechanical data of materials by using a Gleeble need to be defined.

Assessment of the mechanical properties of peruvian Stipa Obtusa fibers for their use as reinforcement in composite materials

This paper presents the study of the mechanical properties of technical fibers extracted from the Stipa Obtusa grass considering three different alkali treatment times, 1.5, 3 and 5 h; additionally, fiber/matrix compatibility is evaluated via the single fiber fragmentation test, and the best treatment in terms of mechanical properties and compatibility is used to test the effect of gage length, strain rate and cyclic deformation. Result shows that mechanical properties increase with treatment time until a maximum (strength ~ 569 MPa, modulus ~ 28 GPa and strain 0.026), and afterwards decreases; furthermore, strength and strain decreases as the fiber length increases; while, the strain rate’s effect is negligible unless at very low speed, and a cyclic deformation leads to an increase of the modulus (~13%). It can be concluded that fibers extracted from the Stipa Obtusa show potential and can compete with commercial natural fibers as a reinforcement in polymeric matrix composites.

Strain microseismics: Radiation patterns, synthetics, and moment tensor resolvability with distributed acoustic sensing in isotropic media

We have derived analytical formulations for the strain field produced by a moment tensor source in homogeneous isotropic media. Such formulations are important for microseismic projects that increasingly are monitored with fiber-optic distributed acoustic sensing (DAS) systems. We find that the spatial derivative of displacement produces new terms in strain proportional to [Formula: see text] with [Formula: see text]. In viscoelastic media, the derivative also produces an additional far-field term that is scaled by a frequency-dependent factor. When comparing with full wavefield synthetic data, we observe that the new terms proportional to [Formula: see text] can be considered part of a near-field in strain, similar to the practice with the displacement formulation. Analyses of moment tensor resolvability show that full moment tensors are resolvable with P-wave information from two or more noncoplanar vertical DAS cable geometries if intermediate- and far-field terms are considered and that S-wave information alone cannot constrain full moment tensors using only vertical wells. These results mirror previous observations made with displacement measurements. Furthermore, the addition of the new terms proportional to [Formula: see text] in strain improves the moment tensor resolvability but only in the case of a single vertical array. In the case of a single deviated/horizontal well, we can, in theory, resolve a full moment tensor but a case-by-case analysis is necessary to identify regions of full constraint around the well and the necessary noise conditions to guarantee reliable solutions. Real DAS measurements also are affected by the gauge length and interrogator details. In the case of the gauge length, we observe that this operator does not change the resolvability of the problem but it does affect inversion stability. The results derived here represent theoretical limits or in some cases specific examples. Practical implementations require analyses of conditioning, noise, coupling, and the effect of gauge length on a case-by-case basis.

In-situ observation of cutting-induced failure processes of single high-performance fibers inside a SEM

Insight into the detailed fracture processes of single high-performance fibers improves understanding for the nature of their unique resistances to external loads. Here, we show the in-situ observation of entire fracture processes of an uncoated single Kevlar® KM2 Plus and Dyneema® SK76 fiber cut by a razor blade at various angles in a Scanning Electronic Microscope (SEM), including initial contact, deformation, crack initiation and propagation until final failure. The effects of gauge length, sputter coating of the platinum, fiber type and cutting angle on the fiber failure were investigated and discussed. The mass-efficient cutting resistance of a single fiber was evaluated by the specific energy. The diversity of the failure modes and cutting resistance were analyzed and attributed to the specific fiber nanostructure and different cutting angles.

Effect of Gauge Length on Tensile Properties of Veldt Grape Fibre

This work analyse fibre gauge length effect on tensile behavior of veldt grape fibre (VGF) were analysed and also examine the actual cross sectional area of VGF were analysed using digital image processing techniques. The single fibre VGF tensile properties is measured using five different gauge length are 10, 20, 30, 40 and 50mm. The ultimate tensile strength, tensile modulus, and strains to failure are noted individually. For predicting the exact tensile properties, under each gauge length of VGF tensile test is conducted for 100times. Totally 500t tensile test values are reported with various gauge length for study the weibul distribution analyse. A strong correlation was noted between the fibre gauge length and fibre tensile strength. It was noted that, when the gauge length is increases, then the fibre strength and strain values are drops. The single fibre failure was analysed using two way ANOVA statistical calculation. Due to the increase in length the possibility of failure (weak point) also increases this statement is proved by existing study using weibull distribution. In our case also we are getting the same result by using another method called correlation.

Determination of cross-sectional area of natural plant fibres and fibre failure analysis by in situ SEM observation during microtensile tests

Reported tensile mechanical properties of many natural plant fibres vary to a large extent due to very often inappropriate measurement of the fibre’s cross-sectional area by diameter estimation. Using natural ramie filament as a model testing elementary fibre, a more realistic stereological determination is presented, including microscopic imaging analysis of the fibres’ cross-sectional area. When applying the area data using this approach to calculate tensile strength, a far narrower variation in the fibres’ strength distribution according to Weibull analysis was found. The gauge length effects on the mechanical performance of the natural fibre were revealed and analysed. In addition, in situ SEM observations during microtensile measurements detected real time changes in the fibres’ structure during stress. It was found that fibre failure was mainly caused by macroscopic physical defects and associated microscopic slippage of the microfibrils. Furthermore, results of cyclic tensile tests indicated that the fibre underwent elastic deformations under progressive loading–unloading cycles, which is due to bonding restriction that the surrounding matrix presents against the slippage of the microfibrils and reorganisation of hydrogen bonds.

Experimental characterization of anisotropic tensile mechanical behavior of pure titanium tube

The anisotropic tensile mechanical properties of pure titanium (TA2) tubes were studied by means of theoretical analysis, finite element simulation and tensile tests. Based on the stress analysis of circumferential tensile of TA2 tube, an equation for calculating the tangential force of circumferential tensile specimen was established, and the relationship among tangential force, friction and position of ring specimen was analyzed. The finite element simulation analysis of circumferential tensile process of TA2 ring specimen was carried out, which verified the tangential force equation derived from theoretical analysis. The effect of gauge length and friction on necking and tensile load was analyzed, and the optimal gauge length was selected for the ring hoop tensile test. Finally, the axial and circumferential tensile digital image correlation experiments were carried out to verify the theoretical and finite element simulation results. The friction coefficient between TA2 tube and D-blocks (using Teflon lubricant) was determined by the inverse finite element method and the friction experiment, and the true stress–strain curve of TA2 tube was obtained. The results show that the axial and circumferential mechanical behaviors of TA2 tubes are significantly different and anisotropic.

Effect of gauge length on loop strength of sewing threads

Seam strength prediction using loop strength has been found to be more accurate and has been consistently used by researchers over last few decades. But the testing gauge length for loop strength has not been standardized as in the case of thread tensile strength. In this paper, effect of gauge length on thread tensile strength and elongation in loop form and straight form has been studied. 40 tex and 60 tex mercerized cotton and spun polyester threads are used for the study. It is observed that there is no significant change in the loop strength of the threads as the gauge length increases, whereas the tensile strength of all threads decreases with the increase in gauge length. Elongation % is found to change significantly in both loop and straight form during tensile testing. Therefore, it is concluded that loop strength tests can be carried out at any gauge length unlike tensile testing of straight threads.

The effect of gauge length on axially incident P‐waves measured using fibre optic distributed vibration sensing

ABSTRACTDistributed vibration sensing, also known as distributed acoustic sensing, is a relatively new method for recording vertical seismic profile data using a fibre optic cable as the sensor. The signal obtained from such systems is a distributed measurement over a length of fibre referred to as the gauge length. In this paper, we show that gauge length selection is one of the most important acquisition parameters for a distributed vibration sensing survey. If the gauge length is too small, then the signal‐to‐noise ratio will be poor. If the gauge length is too large, resolution will be reduced and the shape of the wavelet will be distorted. The optimum gauge length, as derived here, is a function of the velocity and frequencies of the seismic waves being measured. If these attributes vary considerably over the depth of a survey, then the use of different gauge lengths is recommended. The significant increases in data quality resulting from the use of multiple gauge length values are demonstrated using field data.

Effect of Length of False Banana Fibre (Ensete ventricosum) on Mechanical Behaviour under Tensile Loading

Abstract The effect of gauge length of false banana fibre (Ensete ventricosum) on the tensile strength, volume energy, and modulus of elasticity under tensile loading was examined. Fibres of gauge length L 0 (mm) 10, 20, 40, 80, 160, and 320 mm were prepared and tested until rupture point at strain rate of 0.05 min−1. Mathematical models describing the mechanical behaviour of the varying gauge lengths were presented. With the increasing gauge length of fibre, the tensile strength and volume energy decreased while the values of modulus of elasticity increased. The theoretical model describing the mechanical behaviour of Ensete fibre under tensile loading presented herein provides useful information for the fibres application in industry. The determined models could be used as a background for further research focused on Ensete fibre application.

Statistical Analysis of the Tensile Strength of Treated Oil Palm Fiber by Utilisation of Weibull Distribution Model

Oil palm fiber (OPF) extracted from empty fruit bunches is proven as a good raw material for bio-composites. The statistical variability in single fiber strength was observed due to the randomly distributed flaws along the fiber. In this study, the effect of gauge length on tensile strength of OPFs has been investigated. The Weibull/ weakest link distribution model was applied to analyse the statistical strength of OPFs. The modified Weibull distribution can predict the gauge length effect more accurately than the conventional Weibull distribution. In addition, the failure strength of the OPF was less sensitive to gauge length compared to coir fiber even though the OPF has a similarity in structures to coir fiber.