Steel Ribbons Research Articles

Standardisation concept for rapid testing of effects of cutting on losses of electric steel and amorphous ribbon

Standardisation concept for rapid testing of effects of cutting on losses of electric steel and amorphous ribbon

Effect of wheel speed on the microstructure and magnetic properties of Fe-3.0 wt %Si non-oriented silicon steel ultra-thin ribbons prepared by planar flow casting

Using the planar flow casting method to prepare ultra-thin silicon steel ribbons is an eco-friendly and efficient production method. However, the poor wettability between silicon steel and copper result in difficulties in formability by planar flow casting, which limits its application in production of silicon steel ultra-thin ribbons. The process parameters of planar flow casting are the key factors affecting the formability and magnetic properties of non-oriented silicon steel ribbons, in which the wheel speed determines the solidification rate of the silicon steel melt, which has an important influence on the surface quality and magnetic properties of silicon steel ultra-thin ribbons. Therefore, in this paper, the effect of wheel speed on microstructures and magnetic properties of Fe-3.0 wt %Si alloy are systematically investigated. The results indicate that as the wheel speed increases, the grain size and thickness gradually decrease. When the wheel speed is between 10 and 15 m/s, the surface of the ribbons is relatively flat. As the wheel speed increases, the surface quality of ribbons gradually deteriorates. The ribbons were in fragment with the wheel speed of 35 m/s. Compared with the ribbons before annealing, the magnetic induction B50 increased significantly and the iron losses P1.0/400 decreased sharply at 400 Hz after annealing. The magnetic induction of the ribbons after annealing with the wheel speed of 10 m/s reaches to 1.628 T as the wheel speed is 10 m/s with the corresponding iron loss is 16.171 W/kg. The lower lamination factor and micropores of the ribbons may cause the poorer magnetic properties.

Production Efficiency of Ribbon-Type Sections by the Drawing Method in Doubled-Roll Roller Dies

Introduction. The process of drawing is used to produce a wide range of fashion sections of complex configuration, including thin-walled, ribbon-type, and periodical section profiles.Problem Statement. Because of the complexity of steel ribbon production with flattening machines and high capital intensity of flattening production, since the second half of last century, the manufacturers have been trying to use alternative methods of flattening, in particular drawing in monolithic and double-roll roller dies.Purpose. The purpose of this research is to establish regularities of the influence of different sizing systems and process parameters on the regularities of shape change and energy-force parameters of the drawing process in double-roll roller dies and to determine the most effective schemes for achieving the maximal metal expansion while producing ribbon-type sections.Material and Methods. The materials used are as follows: round billets of 5.9 mm in diameter, made of steel brand St.08А; the methods used are as follows: cool billet processing with varying crimping in the double-roll rol ler die with different gauge systems.Results. The regularities of metal shape change and energy-force parameters alternation of the ribbon-type sec tion drawing process in doubled double-roll roller dies by using different gauge systems have been established. Marginal conditions of the deformation in double-roll dies, which provide stable and smooth drawing process according to the criterion of deformed metal safety factor, have been studied experimentally. The most efficient gau ge system of doubled roller dies, which provides maximal metal expansion while producing ribbon-type sections have been determined experimentally.Conclusions. It has been proposed to use the metal drawing technology in doubled double-roll roller dies with “bullhead-accelerated gauge” system while producing ribbon-type sections with a width-to-thickness ratio of more than 2, for achieving the maximal metal expansion per transition. In addition, such a process is energy efficient as the force of pulling through the roller die decreases.

Experimental investigation on the deformation and damage of steel ribbon wound vessel for hydrogen storage under external impact and blast loading

Steel ribbon wound vessel is a preferred type for stationary storage of high-pressure hydrogen in refueling stations. However, it is under the threat of fragment impact and blast loads caused by accidental explosions of hydrogen or other vessels. For the first time, the fragment-simulating projectile (FSP) impact tests with impact kinetic energy range from 1.8 × 103 J–4.9 × 103 J and external blast loading tests with TNT equivalent range from 157 g–4 kg of industrial-grade 50 MPa steel ribbon wound vessel were carried out. The damage of vessel under FSP impact loading was studied. The effect of concentrated and distributed blast loads on the deformation and damage of gas-filled vessel was analyzed, and the explosion resistance of vessel under near-field blast loading was explored. It is revealed that: 1) the steel ribbon wound vessels generally have good resistances to external blast and impact loads, 2) the primary damage characteristics of vessel under contact/near-field blast loading was localized depression deformation, accompanied by steel ribbons warping as the shock wave impulse increases, 3) the saddle fails earlier than the vessel under the near-field blast loading. Further, the failure modes of vessel under extreme blast loads were revealed. Results can provide reference for the safe design and validation of dynamic damage/failure analysis models of steel ribbon wound vessels.

Attaining a Beam-Like Behavior with FRP Strips and CAM Ribbons

Abstract One of the major concerns in the seismic retrofitting of masonry walls is that of increasing the ultimate load for out-of-plane forces. In multi-story buildings, these forces may originate from the hammering actions of floors, when the earthquake direction is orthogonal to the wall. A possibility for counteracting the out-of-plane displacements is retaining the wall by building some buttresses, that is, some beams lean against the wall and disposed vertically. Another possibility is to make the buttress in the thickness of the wall. In this second case, we must cut the wall for its entire height, realize the buttress, and restore the masonry wall around it. In both cases, the interventions are highly invasive. The first intervention also leads to increments of mass that enhance the attraction of seismic forces. The aim of this paper is to find a less invasive and lighter alternative for realizing buttresses. We proposed to use FRP strips and steel ribbons in a combined fashion, so as to realize an ideal vertical I-beam embedded into the wall, without requiring to cut the masonry. We also provided some experimental results for verifying the effectiveness of the model.

Effectiveness of Active Confinement Techniques with Steel Ribbons: Masonry Buildings

Abstract In the present paper, we analyzed the main advantages of the active confinement techniques with a particular focus on the CAM system, which is an Italian reinforcement technique with pre-tensioned stainless-steel ribbons. Italian seismic codes classify the CAM system as belonging to the strengthening category of “horizontal and vertical ties”. Therefore, we compared the CAM system to the reinforcement techniques with horizontal and vertical ties in order to understand the actual similarities and possible differences between them. Moreover, we offered a deep analysis of the main critical issues of the CAM system, distinguishing between geometrical and mechanical weak-points. In particular, we analyzed the strengthening mechanism of the CAM system, still poorly understood, by performing a static analysis in the Mohr/Coulomb plane. Finally, we provided suggestions for future developments.

The development of nature-inspired gripping system of a flat CFRP strip for stress-ribbon structural layout

Abstract The elegant stress-ribbon systems are efficient in pedestrian bridges and long-span roofs. Numerous studies defined corrosion of the steel ribbons as the main drawback of these structures. Unidirectional carbon fiber-reinforced polymer (CFRP) is a promising alternative to steel because of lightweight, high strength, and excellent corrosion and fatigue resistance. However, the application of CFRP materials faced severe problems due to the construction of the anchorage joints, which must resist tremendous axial forces acting in the stress-ribbons. Conventional techniques, suitable for the typical design of the strips made from anisotropic material such as steel, are not useful for СFRP strips. The anisotropy of СFRP makes it vulnerable to loading in a direction perpendicular to the fibers, shear failure of the matrix, and local stress concentrations. This manuscript proposes a new design methodology of the gripping system suitable for the anchorage of flat strips made from fiber-reinforced polymers. The natural shape of a logarithmic spiral Nautilus shell describes the geometry of the contact surface. The continuous smoothly increasing bond stresses due to friction between the anchorage block and the CFRP strip surface enable the gripping system to avoid stress concentrations. The 3D-printed polymeric prototype mechanical tests proved the proposed frictional anchorage system efficiency and validated the developed analytical model.

Effects of Flexural Stiffness on Deformation Behaviour of Steel and FRP Stress-Ribbon Bridges

Stress-ribbon systems develop the most flexible and slender bridges. A structural system of such elegant bridges consists of cables or ribbons and deck slabs placed to these strips to distribute the live load. Although this structural system is simple, the design of such structures is a challenging issue. Design limitations of the bridge deck slope induce considerable forces in the ribbons, which transfer the tension to massive foundations. The deformation increase under concentrated and asymmetrical loads causes another problem of stress-ribbon bridges—the kinematic component, the design object of such structures, exceeds the dead load-induced vertical displacement several times. This paper introduces a new concept of such a structural system, comprising ribbons made of flexural-stiff profiles. The proposed approach to reduce kinematic displacements is illustrated experimentally by testing two pedestrian bridge prototypes with different flexural stiffness of the steel ribbons. Numerical models calibrated using the test results are used for the parametric analysis of the flexural stiffness effect on the deformation behaviour of the bridge system with steel and fibre-reinforced polymer (FRP) ribbons. A practical approach to the choice of the efficient flexural stiffness of the ribbon-profiles is also proposed.

Deformability of Steel-Fiber Beams with External Tape Reinforcement

In 2013, the Lviv National Agrarian University patented the construction of a steel-fiber concrete beam, additionally reinforced with an external steel ribbon armature with end anchors. This technical solution allows reducing the cost of the structure by reducing the complexity of its manufacture, due to the absence of a reinforcing frame in the structure. The purpose of this work is to develop proposals for a refined calculation method of deflections of steel-fiber concrete beams with tape reinforcement on the basis of our experimental studies. 3 beams with dimensions 1500x150x60 mm were manufactured. Beam B-1, reinforced with steel tape 1500x60x3 mm with end stops, did not contain fiber. Beams BF-2 and BF-3 in addition to the specified reinforcement contained fiber, corresponding the coefficient of fiber reinforcement by volume, ρfν = 1,5% i 2% respectively. Compressed prisms of 400x100x100 mm and stretched samples of 700x100x60 mm were also tested to determine the mechanical characteristics of concrete and steel-fiber concrete. Loose beams with a working run of 1400 mm were tested with concentrated force applied along the middle of the length. Mass production fiber produced both in Ukraine and abroad with bent ends HE 1050 1 mm in diameter and 50 mm in length was used for reinforcement. The percentage of fiber reinforcement by volume of concrete beams was taken ρfν = 1.5% and 2% to provide enough bearing capacity of the inclined sections. The cement of grade 400 (activity 42.3 MPa) of the Ivano-Frankivsk plant was used to obtain C20 /25 concrete. The test samples were made of fine-grained concrete containing sand from the Yasinets quarry with a fineness modulus of not more than 2.5. Mixtures for beams were made in a forced mixer. The composition of the mixture was chosen so that the settling of the cone did not exceed 4-6 cm and that the fiber did not settle to the bottom of the form. The composition of the mixture per 1 m3 of the mixture was as follows: cement - 549 kg, sand - 1647 kg, water - 285,5 l. The deflections of the steel-concrete beams were smaller than the steel-concrete beams at equal moments. For example, at the moment of 210 kN·cm the experimental deflection values of beams B-1, BF-2 and BF-3 were equal to 0.116; 0.081 and 0.064 cm, and at the moment 420 kN·cm - 0.380; 0.213 and 0.140 cm, respectively. In this paper, it is proposed to determine deflections using the Mora integral and taking into account the results of the calculation of beams by deformation method. The ratio of theoretical and experimental values of deflections was equal to 0.93 … 1.14.

Reading depth of the magnetic Barkhausen noise. II. Two-phase surface-treated steels

This second part of the work estimates the reading depth of the magnetic Barkhausen noise, testing surface-treated steels. The concomitant changes of the surface microstructure result in a pronounced two-peak profile of the Barkhausen noise signal: an additional peak arising from the surface-treated layer suppresses the initial peak generated in the bulk material. To confirm and explain the results obtained for semi-hard steel ribbons in the first part of this work (Stupakov et al., 2020), the steels with opposite surface treatments (soft decarburized and hard milled layers of different thickness) have been measured by commonly used detection sensors: classical sample-wrapping and industrial surface-mounted coils. To obtain physically accurate data, dynamic variations of the Barkhausen noise signal have been corrected using the recently proposed dH/dt normalization of its rms envelopes.

Reading depth of the magnetic Barkhausen noise. I. One-phase semi-hard ribbons

The aim of this two-part work is to determine the effective depth from which the magnetic Barkhausen noise is detected. To achieve this, we have tested different materials for which the effect of reading depth is critical. This first part presents results of the measurements of a set of martensitic steel ribbons. The ribbons of varying thicknesses (from 10 μm up to 1 mm) have been measured in different magnetizing configurations (solenoid and yokes) ensuring homogeneous quasi-static magnetization. The Barkhausen noise signal obtained has a standard one-peak profile. The rms intensity of the Barkhausen noise signal rises up to a ribbon thickness of ~200μm when a sample-wrapping search coil is used for detection. However, the practical industrial method of the surface-mounted bobbin coil gives a lower rise of the rms intensity in a smaller thickness range up to ~50μm.

Determination of the Optimum Percentage of High Strength Bars in RC Beams with Combined Reinforcement Using Fem

Abstract In this work on the basis of the developed and tested mathematical model, the numerical experiment is conducted in order to study in more detail the specifics of performance of concrete beams` with combined reinforcement. For this purpose nine series of reinforced concrete beams with different combination of steel bars (A400C, At800, A1000) and ribbon reinforcement (C275) were modeled. In the developed series two classes of concrete were used: C50/60, C35/45. The functions derived on the basis of mathematical modeling allow us to determine the recommended percentage of high-strength reinforcement of common reinforced concrete structures with single reinforcement. Therefore, the possibility is obtained to reduce the total structures` reinforcement percentage, increasing their deformability by the specified value without affecting the bearing capacity.

Wire Ropes and CFRP Strips to Provide Masonry Walls with Out-Of-Plane Strengthening.

The present paper deals with an improvement of the strengthening technique consisting in the combined use of straps—made of stainless steel ribbons—and CFRP (Carbon Fiber Reinforced Polymer) strips, to increase the out-of-plane ultimate load of masonry walls. The straps of both the previous and the new combined technique pass from one face to the opposite face of the masonry wall through some holes made along the thickness, giving rise to a three-dimensional net of loop-shaped straps, closed on themselves. The new technique replaces the stainless steel ribbons with steel wire ropes, which form closed loops around the masonry units and the CFRP strips as in the previous technique. A turnbuckle for each steel wire rope allows the closure of the loops and provides the desired pre-tension to the straps. The mechanical coupling—given by the frictional forces—between the straps and the CFRP strips on the two faces of the masonry wall gives rise to an I-beam behavior that forces the CFRP strips to resist the load as if they were the two flanges of the same I-beam. Even the previous combined technique exploits the ideal I-beam mechanism, but the greater stiffness of the steel wire ropes compared to the stiffness of the steel ribbons makes the constraint between the facing CFRP strips stiffer. This gives the reinforced structural element a greater stiffness and delamination load. In particular, the experimental results show that the maximum load achievable with the second combined technique is much greater than the maximum load provided by the CFRP strips. Even the ultimate displacement turns out to be increased, allowing us to state that the second combined technique improves both strength and ductility. Since the CFRP strips of the combined technique run along the vertical direction of the wall, the ideal I-beam mechanism is particularly useful to counteract the hammering action provided by the floors on the perimeter walls, during an earthquake. Lastly, when the building suffers heavy structural damage due to a strong earthquake, the box-type behavior offered by the three-dimensional net of straps prevents the building from collapsing, acting as a device for safeguarding life.

The Design of Rollers for Rolling Corrugations in the Ribbon

Corrugated stainless steel ribbon is used as a working element in modern heat exchangers designed for high working temperatures (up to 1000°C). Making corrugations on the ribbon is the most time-consuming operation, which determines the relevance of the study subject. The article offers a method for calculating the tool profile, provided that the centroid is on the outer diameter of the tool. According to the results of calculations and practical studies, this method should be applied. The profile of the rollers was profiled depending on the specified ribbon profile, limits of ribbon profile parameters are determined. The study subject is to determine the grooves profile of the rolling rollers and to determine rational methods for visualizing the rolling process in order to simulate it. To accomplish this aim, the following tasks are to be solved: 1. To determine the rational position of the centroid during the rolling of corrugations on rollers. 2. To determine the parameters of the profiles when the tool centroids are located on the outer diameter of the rollers in the rolling process.

Combined Strengthening Techniques to Improve the Out-of-Plane Performance of Masonry Walls.

The purpose of this study is to improve the performance of walls under out-of-plane loads especially when subjected to the hammering action of the floors. The idea behind the paper is to provide the masonry walls with a device that behaves like a buttress, without having to build a traditional buttress. The solution presented in this paper consists of a mechanical coupling between the three-dimensional net of steel ribbons of the CAM (Active Confinement of Masonry) system and the CFRP (Carbon Fiber Reinforced Polymer) strips. Since the steel ribbons of the CAM system have a pre-tension, the mechanical coupling allows the steel ribbons to establish a semi-rigid transverse link between the CFRP strips bonded on the two opposite sides of a wall. Therefore, two vertical CFRP strips tied by the steel ribbons behave like the flanges of an I-beam and the flexural strength of the ideal I-beam counteracts the out-of-plane displacements of the wall. The experimental results showed that the combined technique inherits the strong points of both constituent techniques. In fact, the delamination load is comparable to that of the specimens reinforced with the CFRP strips and the overall behavior is as ductile as for the specimens reinforced with the CAM system. They also inspired a more performing combined technique.

Attaining a Beam-Like Behavior with FRP Strips and CAM Ribbons

One of the major concerns in the seismic retrofitting of masonry walls is that of increasing the ultimate load for out-of-plane forces. In multi-story buildings, these forces may originate from the hammering actions of floors, when the earthquake direction is orthogonal to the wall. A possibility for counteracting the out-of-plane displacements is retaining the wall by building some buttresses, that is, some beams lean against the wall and disposed vertically. Another possibility is to make the buttress in the thickness of the wall. In this second case, we must cut the wall for its entire height, realize the buttress, and restore the masonry wall around it. In both cases, the interventions are highly invasive. The first intervention also leads to increments of mass that enhance the attraction of seismic forces. The aim of this paper is to find a less invasive and lighter alternative for realizing buttresses. We proposed to use FRP strips and steel ribbons in a combined fashion, so as to realize an ideal vertical I-beam embedded into the wall, without requiring to cut the masonry. We also provided some experimental results for verifying the effectiveness of the model.

Effectiveness of Active Confinement Techniques with Steel Ribbons: Masonry Buildings

In the present paper, we analyzed the main advantages of the active confinement techniques with a particular focus on the CAM system, which is an Italian reinforcement technique with pre-tensioned stainless steel ribbons. Italian seismic codes classify the CAM system as belonging to the strengthening category of “horizontal and vertical ties”. Therefore, we compared the CAM system to the reinforcement techniques with horizontal and vertical ties in order to understand the actual similarities and possible differences between them. Moreover, we offered a deep analysis of the main critical issues of the CAM system, distinguishing between geometrical and mechanical weak-points. In particular, we analyzed the strengthening mechanism of the CAM system, still poorly understood, by performing a static analysis in the Mohr/Coulomb plane. Finally, we provided suggestions for future developments.

Effectiveness of Active Confinement Techniques with Steel Ribbons: Masonry Buildings

Abstract In the present paper, we analyzed the main advantages of the active confinement techniques with a particular focus on the CAM system, which is an Italian reinforcement technique with pre-tensioned stainless steel ribbons. Italian seismic codes classify the CAM system as belonging to the strengthening category of “horizontal and vertical ties”. Therefore, we compared the CAM system to the reinforcement techniques with horizontal and vertical ties in order to understand the actual similarities and possible differences between them. Moreover, we offered a deep analysis of the main critical issues of the CAM system, distinguishing between geometrical and mechanical weak-points. In particular, we analyzed the strengthening mechanism of the CAM system, still poorly understood, by performing a static analysis in the Mohr/Coulomb plane. Finally, we provided suggestions for future developments.

Attaining a Beam-Like Behavior with FRP Strips and CAM Ribbons

Abstract One of the major concerns in the seismic retrofitting of masonry walls is that of increasing the ultimate load for out-of-plane forces. In multi-story buildings, these forces may originate from the hammering actions of floors, when the earthquake direction is orthogonal to the wall. A possibility for counteracting the out-of-plane displacements is retaining the wall by building some buttresses, that is, some beams lean against the wall and disposed vertically. Another possibility is to make the buttress in the thickness of the wall. In this second case, we must cut the wall for its entire height, realize the buttress, and restore the masonry wall around it. In both cases, the interventions are highly invasive. The first intervention also leads to increments of mass that enhance the attraction of seismic forces. The aim of this paper is to find a less invasive and lighter alternative for realizing buttresses. We proposed to use FRP strips and steel ribbons in a combined fashion, so as to realize an ideal vertical I-beam embedded into the wall, without requiring to cut the masonry. We also provided some experimental results for verifying the effectiveness of the model.

Push-over analysis of a rubble full-scale masonry wall reinforced with stainless steel ribbons

Many strengthening techniques for masonry structures were thoroughly investigated in several researches. The in plane shear behaviour of an ancient full-scale masonry wall, characterized by an opening that is strengthened by the lintel in the arch form, retrofitted with an innovative system constituted by three-dimensional pre-tensioned stainless steel ribbons, was previously tested. In this paper the double flat-jack test results were analyzed and design of the retrofitting system was detailed. The collapse mechanisms in terms of flexural bending and shear, both sliding and diagonal tension, as function of the compression stress level were taken into account. The arrangement of the ribbons was established on the base of an equivalent frame model of the masonry wall, investigating the flexural and shear strength of each element (piers and spandrel). Moreover, the numerical results of the response behaviour modelling of the unreinforced and reinforced masonry wall were presented. The analytical modelling of the wall was accomplished suitably applying the methods of the disturbed stress field model, successfully used for reinforced concrete elements. The numerical results provided a good prediction of the response behaviour of the wall, both in terms of load–displacement curve and crack pattern at failure.