Edge Wedge Research Articles

Thirteen vital factors for micro-scale radial turbine vane’s design of geo-solar-powered Brayton cycle applications

The ever-elevating importance of turbines makes enhancing their performance a crucial point. In most cases, the required performance can be achieved by improving the turbine’s components, i.e., its rotary part, stationary part, and volute. However, this requires a lot of effort, especially when dealing with rotary parts that are time-consuming and costly because of the rotor. Having said that, most of the previous studies have improved turbomachinery by using the latter method. The current study, on the other hand, highlights the importance of only one component, the cheaper one, as a key factor. So, once the numerical modelling was validated using a previous experimental published work, fourteen parameters, which represented all the aerofoil’s vane shape (the stationary part of the turbine only) of a micro-scale turbine i.e. 2–12 kW, were accurately studied with the aim of highlighting their influence on both the vane performance, stage operation, and the overall cycle’s performance as well. The results showed that while parameter 14 i.e. Linear Point Advanced Side 2 showed almost no influence and parameters 5 and 6 i.e. Trailing Edge Wedge Angle and Trailing Edge Beta Angle were the most influential ones, all the other parameters showed a significant effect on the overall turbines’ performance, especially at higher PR values. Moreover, the results have also confirmed that the best values of the mentioned parameters are 0.33 mm, 17 Deg., −25 Deg., 41 Deg., 1 Deg., 55 Deg., 0.3 mm, 0 Deg., 19 mm, 31 mm, 77 mm and 0 mm for all thirteen parameters, respectively. This results in enhancing the stator and the turbine efficiency by around 11 % and 5 % respectively, compared to the baseline design.

Effect of near-wall distance on velocity slip and temperature jump conditions in hypersonic rarefied gas flows

In nonequilibrium slip and jump conditions, normal gas velocity and temperature gradients are used to calculate the gas slip velocity and temperature at the surface, respectively. Gökçen et al. (Computational fluid dynamics near the continuum limit, AIAA Paper No. 87-1115, 1987, and Gökçen and MacCormack, Nonequilibrium effects for hypersonic transitional flows using continuum approach, AIAA Paper No. 89-0461, 1989) stated that the tangential velocity and temperature of the gas molecules before a collision with the surface could be interpreted as the macroscopic tangential velocity and temperature of the gas molecules at the so-called near-wall distances auλ and aTλT away from the surface, respectively. The coefficients au and aT are the order of unity. In the present work, new forms of the slip and jump conditions are proposed by modifying the Gökçen slip and jump conditions to include the coefficients (au, aT). Numerical investigations are comprehensively conducted to determine the numerically proper values (au, aT) for the hypersonic rarefied gas flows. Cases such as the circular cylinder in cross-flow and sharp and blunted leading edge wedge are considered in the present work, with nitrogen as the working gas. The simulation results show the significant effects of the coefficients (au, aT) on the accuracy of the slip velocity and surface gas temperature predictions, and the values of au = 1.2 and aT = 1.1 show good agreement with the direct simulation Monte Carlo data.

3D DEWS digital parametric modeling and manufacturing for obtaining the post-cracking parameters of SFRC

A pullout analytical model is introduced to simulate the Double Edge Wedge Splitting (DEWS) test to obtain the tensile post-peak response of steel fiber reinforced concretes. One of the main barriers to the widespread utilization of FRC as a structural system is the anisotropy of the material. This augments the uncertainty of the material behavior (fibers random distribution and orientation in the bulk concrete), increases the dispersion of the test results, and requires the performance of characterization tests to check the residual tensile stresses at specific crack opening intervals. The characterization tests proposed in the literature (e.g., Barcelona, Montevideo, Wedge Splitting Test, EN 14651) are time-consuming and relatively complex, demanding careful preparation and hydraulic presses with data acquisition systems. This paper aims to contribute to the discussion of alternatives for FRC characterization procedures by the introduction of a pullout analytical model to predict FRC constitutive law based on DEWS tests. The pullout analytical model is calibrated with pullout tests considering straight and hooked-end steel fibers with different strengths, embedment lengths, inclinations, and diameters. A 3D digital model reproducing the experimental DEWS samples is developed, considering the fibers’ randomness distribution, orientation, and wall effect. The analyses are compared with four different experimental tests. The results define a linear post-peak tensile constitutive law, considering the mean residual stress values at different COD values. The model was able to reproduce the specimens’ production procedures and the fibers’ distribution and orientation correctly. The results demonstrated a good agreement with the experimental data.

EQUILIBRIUM OF A NORMALLY LOADED ELASTIC SHALLOW CYLINDRICAL SHELL WITH DISLOCATIONS AND DISCLINATIONS

We consider the problem of the equilibrium of a normally loaded elastic shallow rectangular circular cylindrical shell, which contains sources of internal stress in the form of fields of continuously distributed edge dislocations and wedge disclinations or other sources, for example, thermal ones. Based on the modified system of Karman equations for the equilibrium of an elastic plate with dislocations and disclinations, a system of nonlinear equilibrium equations for the shell was constructed. The resulting system of equations differs from the Karman system of equilibrium equations for an elastic shallow cylindrical shell under the action of a normal load by the presence on the right side of the continuity equation of a nonzero function, called the incompatibility function, which is expressed through the densities of edge dislocations and wedge disclinations. The edges of the shell are freely clamped or hinged. In the absence of internal stress sources, this system transforms into a system of equilibrium equations for a shallow shell, and in the case of an infinitely large radius of curvature (and the presence of internal stress sources) into a modified system of Karman equilibrium equations for a flexible elastic plate with dislocations and disclinations. To solve the system of nonlinear shell equilibrium equations, the Newton – Kantorovich method in combination with the difference method is proposed. For the case of small values of the normal load and small values of the incompatibility function, linearization is carried out with respect to the deflection and stress function. As a result, a linear boundary value problem was obtained in the form of a system of differential equations for the deflection and the stress function, which is solved by the difference method. The solution of the linearized system is used as an initial approximation in the implementation of the Newton – Kantorovich method. Examples of numerical calculations of deflection and stress function for given values of normal load and incompatibility function are given, and corresponding graphs are constructed.

Determining Degree of Hypertrophy and Extent of Resection in Aesthetic Labia Minora Reduction: Technical Highlights and Step-by-Step Video Guide.

Advances in aesthetic labia minora (LM) procedures have led to better results and fewer complications. Edge trim or wedge approaches are used, both of which use hidden incisions and preserve the edges of the LM. Since 1998, we have been performing a simple and reliable technique based on inferior wedge LM resection and superior pedicle flap reconstruction. Although details of aesthetic LM reduction have been amply published, previous technical videos have not presented a detailed step-by-step description, and few studies specifically address how to estimate the amount of tissue to resect according to the degree of hypertrophy. This article and the accompanying videos provide a detailed guide that clearly outlines the senior author's (A.M.M.) technique for aesthetic LM reduction. The authors' experience demonstrates that superior pedicle flap reconstruction is a reliable and reproducible technique. The success of the procedure depends on patient selection, careful preoperative planning, and adequate intraoperative management.

Preliminary assessment of the NACA0021 trailing edge wedge for wind turbine application

The airfoil blade is the primary component of a wind turbine, and its aerodynamic properties play a crucial role in determining the energy conversion efficiency of these blades. Many researchers have proposed different airfoil modifications intending to enhance the aerodynamic characteristics and limit the unsteady interaction with the atmospheric boundary layer. This study evaluates the benefits of mounting wedge tails (WTs) on the trailing edge of an airfoil. The aerodynamic characteristics of a 2-D, steady-state NACA 0021 airfoil featuring the wedge tails (WT) and fish wedge tails (FWT) were studied computationally by employing the shear stress transport (SST) k-ω turbulence model. Different WT and FWT configurations were studied at various wedge length (L) to wedge height (H) ratios, L/H, at the airfoil's trailing edge. The effects of different L/H ratios, including L/H > 1, L/H = 1, and L/H < 1, were considered in the present study to determine the optimal configuration to achieve the maximum glide ratio, CL/CD at the Reynolds number of 180,000. The findings indicate that the performance of the NACA 0021 airfoil was notably affected by the height of the tail; however, the length had only a minor impact when L/H was less than 1. The mounted FWT resulted in significant enhancements to both the lift and glide ratio of the airfoil. Specifically, the lift ratio experienced an increase of over 41 % compared to the clean airfoil, while the glide ratio increased by more than 31 %. These improvements were observed at an ideal height and length of 2.5 % and 1 % of the airfoil, respectively. Moreover, the mounted FWT performed better than the Gurney flap using the same configurations.

Cellulose nanofibers to improve the mechanical and durability performance of self-healing Ultra-High Performance Concretes exposed to aggressive waters

The effects of including cellulose nanofibers (CNFs) in Ultra High Performance Concretes (UHPCs) have been studied in this paper in terms of recovery of both durability and mechanical properties because of the stimulated self-healing behavior. To this purpose, flexural tests on 4-point bending on 30 mm thin and 100 mm wide beam specimens have been carried out to evaluate the mechanical recovery due to self-healing, together with Double Edge Wedge Splitting tests that have been performed to identify the tensile stress crack-opening behavior. Moreover, water permeability and chloride diffusion tests have been performed to evaluate the recovery of durability properties on healed specimens subjected to extremely aggressive environments rich in chlorides and sulfates. Microstructural analysis has been also performed to confirm the enhancement on durability performance due to the presence of CNFs. The presence of CNFs has improved self-healing performance of UHPC since for the same crack width value and same healing period (1, 3 or 6 months) the specimens with CNFs reached higher crack sealing rates compared to those without nano-additions. As a matter of fact, the total sealing of the cracks over the 6-month investigated period was only observed on specimens with CNFs.

Large Frontal Defect Reconstructed with a Suprafascial Anterolateral Thigh Flap and Brow Suspension with a Fascia Lata Frontalis Sling

A 60-year-old gentleman presented with a single, dark scaly lesion over the forehead for the past 8 years. It started as a small plaque spontaneously, insidious in onset and gradually progressed to the present size. There was no history of trauma, pain or bleeding from the lesion. No history of similar complaints in the family. On examination, there was a large hyperpigmented plaque measuring 15 x 10 cm with well-defined margins and rolled-out edges with ulceration 2 x 0.5cm at the centre. (Fig. 1) Edge wedge biopsy from the lesion revealed a proliferation of basaloid cells which showed features consistent with basal cell carcinoma - atypical mitosis and peripheral palisading. After obtaining anaesthetic fitness, we proceeded with wide local excision with 1cm margin done by the surgical oncology team. (Fig. 2) We then followed by reconstruction of the frontalis sling using fascia lata and covered the defect with a free suprafascial ALT flap with superficial temporal as the recipient artery as an end-to-end anastomosis. (Fig. 3, 4) The donor site was resurfaced with SSG. The histopathology report was consistent with basal cell carcinoma without any perineural involvement. The early postoperative period showed the flap supple and soft with no oedema. (Fig. 5) On regular follow-up, the flap was well settled with good cosmesis. (Fig. 6)

The effect of trailing-edge wedge-tails on the aerodynamic characteristics of wind turbine airfoil

Passive flow control devices have been proposed by many researchers for suppressing dynamic stall and enhancing the aerodynamic performance of turbomachinery including wind turbines. These technologies are usually cheap, easier to implement, and no additional energy needed. In the present study, the effects of adding trailing edge wedge tail (WT)on the aerodynamic characteristics of a static airfoil have been evaluated. The aerodynamic behavior of 2D-NACA0021 airfoil equipped with WT have been studied numerically using the commercial code ANSYS FLUENT to solve the Reynolds-Averaged Navier–Stokes equation (RANS). The effect of varying heights and lengths to height ratios (L/H) of WT have been studied. The results showed that the aerodynamic efficiency of NACA0021 airfoil influenced significantly by height of WTs comparing to slightly influence by length at L/H<1, and the maximum improvements of the lift and lift-to-drag ratio of the airfoil up to more than +38% and 28.8% respectively at optimum height 1.75%c and length 1%c compared to baseline airfoil case and suggested that to add trailing WTs as a retrofit to existing wind turbines.

RAMIFICATION OF EQUILIBRIA OF A COMPRESSED ELASTIC ORTHOTROPIC PLATE WITH INTERNAL STRESSES

The problem of loss of stability and post-critical behavior of a compressed orthotropic rectangular plate on a nonlinearly elastic base containing continuously distributed fields of dislocations and disclinations and under the influence of a small normal load is considered. The compressive force components are evenly distributed along the edges and act parallel to the main directions of elasticity. The problem is formulated as an analogue of a system of nonlinear Karman equations for an orthotropic plate containing a function called the incompatibility measure, which is expressed in terms of the densities of edge dislocations and wedge disclinations. The system of equations takes into account the small transverse pressure and the reaction of the elastic base in the form of a polynomial of the third degree of deflection. The following boundary conditions are considered: the edges of the plate are freely pinched or movably pivotally supported; two opposite edges of the plate are freely pinched or movably pivotally supported, and the other two are free from loads. The stress function is sought in the form of two components: the stress function caused by the presence of internal sources, determined from the linear boundary value problem, and the stress function caused by the external impact of compressive loads and a nonlinear elastic base, which is determined from the nonlinear boundary value problem. The nonlinear boundary value problem is investigated by the Lyapunov – Schmidt method. To solve the linearized equation from which the critical value of the compressive load is determined, the variational method is used in combination with the difference method. A system of branching equations of the Lyapunov – Schmidt method is constructed, which is investigated by numerical methods. The post-critical behavior of the plate is investigated and asymptotic formulas for new equilibria in the vicinity of the critical load are derived. For various values of compressive loads, the orthotropy parameters of the plate and the intensity parameter of internal stresses, the relations between the values of the base parameters are established, at which its bearing capacity is preserved in the vicinity of the classical value of the critical load.

Influence of self-healing property of Ultra-High Performance Concrete under aggressive environment

This paper investigates the evolution of self-healing properties of ultra-high performance concrete exposed to aggressive environments. Double edge wedge splitting UHPC specimens with 0.8% crystalline admixture and 1.5% steel fibre by volume have been first pre-cracked up to a average 0.30 mm crack opening displacement (COD) obtained by two linear variable differential transformers attached to both sides of the sample surface. Then, the pre-cracked samples have been exposed to three different environments: tap water, salt water (a NaCl aqueous solution at 3.3% concentration) and geothermal water obtained from a geothermal power plant. After one month exposure, samples were carried out re-crack to know the self-healing properties. The results from ultrasonic pulse velocity tests (UPV) reveal that the samples exposed to tap water exhibit the highest rate of recovery along the exposure time, while those exposed to geothermal water show the lowest. The calculated indexes of cracking self-healing (ICS) show a 73.8% closure in tap water, 58.4% in salt water 43.9% in geothermal water. Additionally, the index of damage recovery, evaluated from UPV frequencies as well as from the stress vs. COD curves of pre-cracking and post-healing re-cracking tests on specimens, and the equivalent tensile stress also indicate a higher level of healing capable of inducing a significant recovery of mechanical properties.

The Influence of Boundary Layer State and Trailing Edge Wedge Angle on the Aerodynamic Performance of Transonic Turbine Blades

Abstract Trailing edge loss typically accounts for a third of the profile loss of a transonic turbine blade. In this paper, two dominant influencing factors—boundary layer state and trailing edge wedge angle—are quantified using a combined experimental (single airfoil transonic tests) and computational (wall-resolved LES) approach. Three key findings are reported. First, the switch between two flow regimes—detached vortex shedding and transonic vortex shedding—as the Reynolds number is increased, is identified and explained. It is shown that the transition of the pressure surface boundary layer drives the switch from the former to the latter; this change is associated with a jump in loss of close to 100%. The switch is also shown to affect the base pressure distribution around the trailing edge, changing it from uniform, with an isobaric dead-air region, to non-uniform. Second, the influence of the trailing edge wedge angle is explored. It is found that higher wedge angles can offer performance benefits in both loss and base pressure—with a change from 8 deg to 14 deg geometry providing up to a 29% reduction in an overall loss for the geometry tested. Finally, as these findings are the result of changes to the unsteady flow phenomena around the trailing edge, they would not be picked up by current low-fidelity, steady design tools. A method is proposed to use data, such as that presented in this paper, to improve low-fidelity modeling.

Trilobal Methods for Composite Reduction Labiaplasty.

BackgroundIt is difficult to plan a simple and effective surgical strategy for patients with horizontal and vertical redundant tissue of the labia minora and clitoral hood redundancy. A single edge resection or wedge resection labiaplasty with clitoral hood reduction that simultaneously resolves these three issues has yet to be reported. This study investigated the clinical effects and safety of trilobal labiaplasty via a composite incision.MethodsThe single-center, retrospective, observational study included data from patients with hypertrophy of the labia minora and clitoral hood who underwent trilobal labiaplasty.ResultsAltogether, 136 patients (average age: 31.6 ± 8.82 years; range: 21–53 years; 224 sides) sought surgery for aesthetic (39/136, 28.7%), functional (17/136, 12.5%), or both reasons (80/136, 58.8%). Overall, 134 patients (134/136, 98.5%) were followed up for 3 months. No serious complications or malformations occurred. Three patients (2.2%) underwent secondary repair surgery due to incomplete bilateral symmetry, 122 (91.0%) scored ≥ 21 points on the Female Genital Self-Image Scale, 107 (91.5%) were satisfied with the cosmetic outcomes, and 93 (95.9%) were satisfied with the functional improvement.ConclusionsTrilobal labiaplasty performed via a composite incision using edge and wedge labiaplasty to adjust horizontal and vertical hypertrophy of the labia minora and remove lateral folds of the clitoris is a safe and effective method to improve the appearance and rearrange the position of the clitoral hood and clitoral frenulum while preserving the fine structure of the surrounding tissue. This method results in few complications and high functional and aesthetic satisfaction rates.Level of Evidence IVThis journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Marjolin’s ulcer

A 42-year-old lady presented with complaints of a slow growing fungating growth over the left shoulder of 3 months duration. This was associated with pain of 2 weeks duration and occasional sero-purulent discharge. Past history of burns to the upper torso, neck and back sustained 15 years ago was elicited. Physical examination revealed a large ulcero-proliferative growth involving the left shoulder and upper arm with areas of scarring and contractures adjacent to the lesion (Figure 1). There was no axillary adenopathy. Rest of the examination was unremarkable. Edge wedge biopsy revealed moderately differentiated squamous cell carcinoma. Computerized Tomogram (CT) of the thorax showed the tumor was infiltrating into the adjacent soft tissues, with no regional adenopathy or pulmonary metastases. The patient underwent wide local excision. Histopathological examination confirmed moderately differentiated squamous cell carcinoma with negative margins.

Local Thickenings and Thinnings of Hot Rolled Strips

The cross-section profile of the rolled strip is characterized by geometrical parameters such as wedge, convex, difference of thickness, edge wedge and others. Techniques for calculating the values of these parameters are known and generally accepted. However, there are features of the cross-section profile of rolled strips, such as local thickenings/thinnings, the methods of calculating values of which are not common: practically every scientific school of specialists of rolling production use their own techniques, which often produce different results for the same cross-section profiles. The problem of identifying and calculating the local thickenings/thinnings parameters of the rolled strips cross-section profile is to define a so-called “zero level”, the excess/understatement of which is a sign of local thickenings/thinnings. The paper analyzes the accuracy and adequacy of the calculation of the cross-section profile parameters of rolled strips for local thickenings/thinnings. A new method based on statistical methods is proposed. The target function that the thickness distribution across the width of the rolled strip must correspond to is a symmetrical quadratic parabola. However, the actual distribution is always different from the target one for a number of reasons, such as ring wear of the work rolls. In the first step, in the proposed technique, the Walter-Shewhart procedure (control cards) eliminates as emissions of strip thickness values that are dramatically different from the target distribution. But since without excluding the nonlinear (parabolic) component of the measured cross-section profile this procedure cannot be applied, it applies to the first derivative of the cross-section profile thickness distribution function. The result of the developed method is a “zero level” according to which the local thickening/thinning parameters are calculated.

Failure behavior of prismatic Li-ion battery cells under abuse loading condition - A combined experimental and computational study

Li-ion jelly rolls and prismatic battery cells were quasi-statically loaded by three different indenters: (1) Hemispherical nose punch, (2) Flat end punch, and (3) Round edge wedge. Force and displacement during indentation were measured. For the cells, voltage drop was also recorded to monitor short circuiting. The deformation/failure modes of specimens were examined and the critical force at initiation of short circuit was analyzed for the cells. Substantial differences occurred depending upon indenter shape; also loading orientation for the wedge. In all cases, short circuiting of the entire cell initiated by formation of the first jelly roll crack. Based on test loading and boundary conditions, finite element (FE) models were developed using explicit FEA code LS-DYNA. The model predictions demonstrated good agreement in terms of force-displacement responses and structural failure modes at both jelly roll and prismatic cell levels. With the validated numerical model, the original battery cell design was modified in order to alter the deformation and failure modes of the jelly roll. Three design modifications were considered: (1) Include a thin mica sheet between the first and second jelly roll layers; (2) Use thinner, but higher stiffness/strength steel to replace the aluminum alloy enclosure material; and (3) Change the enclosure material where indenter contact occurs from an aluminum alloy sheet to an aluminum alloy sandwich structure. All three indentation conditions were simulated and results were compared to the original design. The outcomes were sensitive to indenter shape, where round end wedge indentation benefitted the most. The findings have potential for improving prismatic battery cell safety by incorporating them into future designs.

Technical and environmental potentialities of recycled steel fiber reinforced concrete for structural applications

The use of recycled materials and industrial by-products as sustainable constituents of cement-based materials could be an environmentally and technically promising solution for application to structural elements. In the present work, the technical and environmental impact of using recycled steel fibers as an alternative to industrial steel fibers for concrete reinforcement was assessed at material level. Numerical simulations were performed to derive the post-cracking constitutive laws of the developed Recycled Steel Fiber Reinforced Concrete (RSFRC) and Industrial Steel Fiber Reinforced Concrete (ISFRC) by inverse analysis of experimental results obtained from three-point notched beam bending tests (3PNBBT), round panel tests supported in three points (RPT-3ps) and double edge wedge splitting tests (DEWST). These simulations were able of fitting with high accuracy the experimental results and consequently to derive the tensile stress-crack width relationships of RSFRC and ISFRC that was used to numerically simulate the bending response of a T-cross section steel RSFRC beam failing in shear.The environmental impact of the incorporation of RSF in concrete in comparison with ISFRC was evaluated using Life Cycle Assessment methodology. The reduction of the environmental impact of the production of RSFRC compared to ISFRC with the same concrete strength class is demonstrated.

Effect of high temperature on the mechanical properties of concrete reinforced with different fiber contents

This study evaluates the effect of fiber content on the thermo-mechanical properties of steel fiber reinforced concretes (SFRC) and contributes to the definition of design-oriented parameters for SFRC after temperature exposure, which are limited in literature and current guidelines. The mechanical behavior of samples subjected to high temperatures (25 °C ≤ T ≤ 750 °C) and produced varying the fiber contents were analyzed. The tensile properties were determined using the Double Edge Wedge Splitting (DEWS) test, which proved to be a viable methodology to evaluate the post-crack behavior of SFRC exposed to high temperatures. The rate of degradation in compressive and tensile strength was reduced for higher contents of steel fibers after exposure to elevated temperatures. The reductions in compressive strength and the elastic modulus were more severe than those prescribed by European guidelines. Additionally, the tensile properties reduced significantly for T ≥ 450 °C. Also, a temperature-related reduction rate in the post-crack tensile properties was parameterized for all the fiber content samples, in which only 20% of fFts and 30% of fFtu room temperature values were retained after exposure to 600 °C, which are higher values comparing the European guidelines.

On adequacy of parameters of strip cross-section profile. Part 2. Local thickenings and thinnings

At present, the cross-section profile of the rolled strip is characterized by geometrical parameters such as wedge, convex, difference of thickness, displacement of convex, and edge wedge. Some of these parameters are redundant. Techniques for calculating the values of these parameters are known and generally accepted. However, there are features of the cross-section profile of rolled strips, such as local thickenings/thinnings, the methods of calculating values of which are not common: practically every scientific school of rolling scientists or specialists of rolling production use their own techniques, which often produce different results for the same cross-section profiles. The problem of identifying and calculating the local thickenings/ thinnings parameters of the rolled strips cross-section profile is to define a so-called “zero level”, the excess/understatement of which is a sign of local thickenings/thinnings. The paper continues to analyze the accuracy and adequacy of the calculation of the cross-section profile parameters of rolled strips for local thickenings/thinnings. A new method based on statistical methods is proposed. The target function that the thickness distribution across the width of the rolled strip must correspond to is a symmetrical quadratic parabola. However, the actual distribution is always different from the target one for a number of reasons, such as ring wear of the work rolls. In the first step, in the proposed technique, the Walter-Shuhart procedure (control cards) eliminates as emissions of strip thickness values that are dramatically different from the target distribution. But since without excluding the nonlinear (parabolic) component of the measured cross-section profile this procedure cannot be applied, it applies to the first derivative of the cross- section profile thickness distribution function. To determine the “zero level,” after calculating the upper and lower limits of the allowed values of the first derivative, all thicknesses associated with these emissions were eliminated. The result of the repetitive process is a “zero level” according to which the local thickening/thinning parameters are calculated.

Double Edge Wedge Splitting Test to Characterize the Design Postcracking Parameters of Fiber-Reinforced Concrete Subjected to High Temperatures

AbstractThe determination of the postcrack tensile properties of steel fiber–reinforced concrete (SFRC) after exposure to elevated temperatures is a current methodological challenge. The objective ...