Bending Profile Research Articles

Bending profiles with variable cross section

Profiles with variable cross-sections allow for a load-adapted design of components. Using a newly developed bending process, new lightweight construction potentials can be exploited that were not feasible with the current design restrictions. This helps to save material costs as well as other resources. To bend profiles with a cross-section that varies along the longitudinal axis, it was necessary to develop a new type of bending process. The already established three-roll-push-bending process was further developed so that the individual tool positions in the process can be adapted to the current profile cross-section.

Теоретические и экспериментальные исследования сталежелезобетонных конструкций с применением гнутых стальных профилей

Introduction. The main problem of the behaviour of composite structures is the method of combining materials that have different qualitative characteristics. In the case of collaboration of concrete and steel, the load-bearing capacity of the structure increases, while the consumption of materials decreases. Thanks to these advantages, the use of steel-reinforced concrete floor slabs is more and more popular. A theoretical study has made it possible to assess the load-bearing capacity of a floor slab. Materials and methods. A theoretical analysis of the bearing capacity of a composite floor slab is proposed. Four samples, that consisted of a galvanized steel plate embedded in a concrete parallelepiped, were used to conduct experimental studies. Rectangular plates had different types of surface: smooth, perforated with holes, with stamped “pins”, and with bolted connecting elements. Results. The analysis of the bearing capacity of a steel-reinforced concrete floor slab, that has bent profiles, was performed. The deformation dependences of the experimental samples were obtained; the graphs describing the dependence of displacement on the load for the four types of surfaces are made; the values of the load at which samples fail, and the dependence of the breaking load on the structure of the embedded part of the plate are identified. Conclusions. The analysis of the bearing capacity of a steel-reinforced concrete floor slab, that has bent steel sections, has shown that the use of light steel thin-walled beams is possible if spans correspond to residential and public buildings. The results of the experiment allow to conclude that the collaboration of concrete and a steel beam is possible without any additional elements in the composite structures that have bent sections. Adhesive properties of materials and the stamped part of the section can take the shear forces arising in structures.

Towards a consistent methodology for testing the electromechanical performance of strip polymer composite actuators

Strip actuators have attracted tremendous attention in bionics due to the controllable deformation under various stimuli. However, it is currently hard to compare their performance owing to the different approaches for evaluating their actuation. Most of the studies determine the maximum or average value of the bending angle or strain, the deformation profile of the entire actuator strip was not quantified. In this study, a versatile method was proposed to evaluate the bending profile of typical strip actuators with bending deformation, thus analyzing the actuation performance. This method has been verified by synthetic curves, and less than 2% of global error was found. We have also demonstrated the implementation of this method for examining the actuation of typical strip actuators and showed that it can also be used for comparing the performance of different actuators prepared from other studies.

Behaviour of timber-alternative railway sleeper materials under five-point bending

Timber alternative composite sleepers available in the market have very distinct material properties. These differences affect the track performance when used interspersed with timber sleepers in a railway track. This research employs a newly developed five-point bending test to evaluate the failure behaviour and overall structural performance of timber, low-profile prestressed concrete, synthetic composite and engineered plastic sleepers. The Digital Image Correlation technique was used to capture the full-field profile deformation and was validated with strain data at centre and rail seat locations. The results showed that sleepers with bending modulus higher than timber will exhibit a U-shaped or nearly flat bending profile while those with lower modulus will have a pronounced W-shaped bending profile. This effect is more profound on the centre part than the rail seats. Alternative sleepers also have significantly lower rail seat flexural failure load than timber, i.e. low-profile prestressed sleepers (85%), synthetic composites (56%) and lastly, engineered plastic sleepers (42%). Moreover, each sleeper materials exhibited distinct failure mechanisms, i.e., rail seat flexural crack for timber, longitudinal shear cracks along the length for synthetic, permanent deformation at both the rail seat and centre for engineered plastic, and a combination of shear and flexural cracks for the low-profile concrete sleeper. Foam-based composite sleepers also suffers permanent indentation under the rail seat due to high pressure in these areas. The observations and the findings from this research will enrich the understanding of the behaviour of timber alternative composite sleepers, providing useful guidance to railway track engineers, asset owners and sleeper manufacturers.

Influence of the electromagnetic field pressure on the free bending of the straight side

Bending is the operation of forming or changing the angles between the parts of the workpiece or giving it a curved shape and in the mean time is the most difficult and timeconsuming operation of the technological process of manufacturing parts from profiles. Aircraft bending parts of the following nomenclature are obtained as profiles: frames, ribs, stringers, linings and brackets. Profile parts are responsible for their intended purpose; therefore, high requirements are placed on the accuracy of their dimensions and the preservation of the crosssection shape. The process of bending profiles has its own characteristics, which are due to the shape of the profile section; the first feature is the presence of vertical shelves, significantly loaded and deformed due to large distances from the neutral axis of the bent section, the second is the mismatch of the bending plane with the main axes of inertia of the section, which causes oblique bending and twisting of the part. When analyzing the bending process of extruded profiles, it should be borne in mind that the neutral layer of the workpiece coincides with the line that passes through the centers of gravity of the sections. When using the hypothesis of planar sections of the plot of deformations and stresses in the stretched and compressed zones do not have a mutually reflected form. It is very important how the profile is oriented in the bending plane. Different orientation of the profile, even the simplest cross-section (for example, angular), gives a qualitatively different picture of the deformed state.

Multi-material distribution planning for additive manufacturing of biomimetic structures

Purpose The purpose of this study is to develop a novel approach to designing locally programmed multi-material distribution in a three-dimensional (3D) model, with the goal of producing a biomimetic robot that could mimic the locomotion of living organisms. Design/methodology/approach A voxelized representation is used to design the multi-material digital model and the material distribution in the model is optimized with the aims of mimicking the deflection dynamics of a real-life biological structure (i.e. inchworms) during its locomotion and achieving smooth deflection between adjacent regions. The design is validated post-fabrication by comparing the bending profiles of the printed robot with the deflection reference images of the real-life organism. Findings The proposed design framework in this study provides a foundation for multi-material multi-functional design for biomimicry and a wide range of applications in the manufacturing field and many other fields such as robotics and biomedical fields. The final optimized material design was 3D printed using a novel multi-material additive manufacturing method, magnetic field-assisted projection stereolithography. From the experimental tests, it was observed that the deflection curve and the deflection gradient of the printed robot within the adjacent regions of the body agreed well with the profiles taken from the real-life inchworm. Originality/value This paper presents a voxelized digital representation of the material distribution in printed parts, allowing spatially varied programming of material properties. The incorporation of reference images from living organisms into the design approach is a novel approach to transform image domain knowledge into the domain of engineering mechanical and material properties. Furthermore, the novel multi-material distribution design approach was validated through designing, 3D printing and prototyping an inchworm-inspired soft robot, which showed superior locomotion capability by mimicking the observed locomotion of the real inchworm.

Reduction of Warping in Kinematic L-Profile Bending Using Local Heating

Kinematic bending of profiles allows to manufacture parts with high flexibility concerning the geometry. Still, the production of profiles with asymmetric cross-sections regarding the force application axis using kinematic bending processes offers challenges regarding springback and warping. These geometric deviations can be reduced by partial, cross-sectional heating during the process as it lowers the flow stress locally. In this work, the influence of partial, cross-sectional heating during a three-roll push-bending process on the warping and springback of L-profiles is investigated. Numerical and experimental methods reveal the influence of temperature on warping and springback. A newly developed analytical model predicts the warping and bending moment in the design phase and assists to understand the effect of warping reduction through partial heating during plastic bending. With increasing temperature of the heated profile area, the warping is reduced up to 76% and the springback of the bend profiles is decreased up to 44%. The warping reduction is attributed to a shift in stress free fiber due to the temperature gradient between heated and room temperature areas. The shift of stress-free fiber leads to an adapted shear center position, resulting in an approximated “quasi-symmetric” bending case.

Effect of crystal structure on the Young’s modulus of GaP nanowires

Young’s modulus of tapered mixed composition (zinc-blende with a high density of twins and wurtzite with a high density of stacking faults) gallium phosphide (GaP) nanowires (NWs) was investigated by atomic force microscopy. Experimental measurements were performed by obtaining bending profiles of as-grown inclined GaP NWs deformed by applying a constant force to a series of NW surface locations at various distances from the NW/substrate interface. Numerical modeling of experimental data on bending profiles was done by applying Euler–Bernoulli beam theory. Measurements of the nano-local stiffness at different distances from the NW/substrate interface revealed NWs with a non-ideal mechanical fixation at the NW/substrate interface. Analysis of the NWs with ideally fixed base resulted in experimentally measured Young’s modulus of 155 ± 20 GPa for ZB NWs, and 157 ± 20 GPa for WZ NWs, respectively, which are in consistence with a theoretically predicted bulk value of 167 GPa. Thus, impacts of the crystal structure (WZ/ZB) and crystal defects on Young’s modulus of GaP NWs were found to be negligible.

Экспериментальные исследования силы сцепления стальной оцинкованной пластины и бетона

Introduction. The co-authors present the findings of experimental studies of the adhesion force arising between a zinc-coated steel plate and concrete. Four specimens were used in testing. Rectangular plates, embedded in a concrete parallelepiped, had different types of surfaces. They were smooth, perforated with holes, or they had connecting elements such as bolts or spikes. The behavior of specimens under loading is analyzed; graphs, describing the dependency between displacements and loading are provided, and the design resistance is determined to analyze the adhesion force between concrete and a zinc-coated steel plate. Materials and methods. Four specimens were used in testing. Each specimen represented a zinc-coated steel plate embedded in a concrete parallelepiped. A test bench, consisting of a load frame and a hydraulic cylinder, which pulled the steel plate out of a concrete parallelepiped, was used in the experiment. Results. Deformation dependences of specimens were obtained, graphs describing the dependence of displacement on loa­ding were drawn for four types of surfaces, loading values that trigger the failure of specimens and dependence between the loading value, that triggers the failure, and the structure of the embedded part of the plate, are identified. The nature of the concrete failure at the interface with a zinc-coated plate is tracked. Conclusions. The results of the experiment enable us to conclude that the joint action of concrete and a steel beam is possible without the use of additional elements in composite structures that have bent profiles. The adhesion properties of materials and the stamped part of the profile are capable of absorbing shear forces arising in structures. For a more accurate analysis of floor slabs that contain bent profiles, additional experimental studies are to be conducted. Specimens, having bent profiles embedded in concrete, will be tested in the course of these experiments.

Band bending at heterovalent interfaces: Hard X-ray photoelectron spectroscopy of GaP/Si(0 0 1) heterostructures

GaP is a preferred candidate for the transition between Si and heterogeneous III-V epilayers as it is nearly lattice-matched to Si. Here, we scrutinize the atomic structure and electronic properties of GaP/Si(0 0 1) heterointerfaces utilizing hard X-ray photoelectron spectroscopy (HAXPES). GaP(0 0 1) epitaxial films with thicknesses between 4 and 50 nm are prepared by metalorganic vapor phase epitaxy on either predominantly single-domain (SD) or two-domain (TD) Si(0 0 1) surfaces. The antiphase domain content in the GaP films is in situ controlled, employing reflection anisotropy spectroscopy. Via the analysis of core level photoelectron intensities, we reveal core level shifts of the P 2p and Si 2p peaks near the interface as well as core level shifts in the Ga 3d peaks near the surface. We suggest an Inter-Diffused Layer (IDL) model of the GaP/Si(0 0 1) interfacial structure with SiP bonds at the heterointerface and residual P atoms in the Si substrate. Using a newly developed Parametrized Polynomial Function (PPF) approach, we derive a non-monotonic band bending profile in the heterostructures, correct experimental valence band offsets implying interfacial electronic barriers, and determine valence band discontinuities of ΔEV= 1.1 ± 0.2 eV (SD samples) and ΔEV= 0.8 ± 0.2 eV (TD samples) at GaP/Si(0 0 1) interfaces.

Terahertz emission spectroscopy of GaN-based heterostructures

This study investigates the band bending profile of gallium-nitride-based heterostructures with respect to the change in the direction of the induced current in the out-of-plane plane direction, which gives the phase of the terahertz emission peak and can be detected by laser THz emission microscopy. We use a wavelength-tunable laser THz emission spectroscope to observe the transport of charges within the band bending regions, excitation of nearby photocarriers, and carrier scattering. We observe flip-flop peak-to-peak THz emission waveforms for a GaN heterostructure field-effect transistor (FET) compared to a strong THz emission radiated from an Al0.3Ga0.7N/GaN high-electron-mobility-transistor (HEMT). The flip-flop THz emission indicates the emission from various interfaces inside the FET structure, and intense THz emission from the HEMT structure indicates band-edge excitation. Our results provide a valuable perspective for characterizing complex heterostructures that provide insight into possible defects, carrier mobilities, and band bending of multilayer interface electronic devices.

Profile and contact force estimation of cable-driven continuum robots in presence of obstacles

Accurate prediction of shape and contact forces significantly improves the performance of a continuum robot during its operation in obstacle-laden environments. This paper presents an optimization-based mathematical framework to predict the bending profile of a cable-driven continuum robot in presence of obstacles. The kinematics model is derived from the concept of strain energy minimization and can easily incorporate obstacles as inequality constraints in the optimization-based approach. The location of point of contact can be identified by observing the Lagrange multipliers of the inequality constraints. Using the kinematics model and the principle of virtual work, a method to estimate the reaction forces at contact is proposed. The model shows high accuracy, with RMS error of 1.35 mm in prediction of the pose for experiments conducted on a 180 mm long robot prototype. Validation experiments are also conducted on the prototype by imposing contact at different locations on the robot. In all cases, the average error in predicting the contact force is found to be less than 1.0 g for applied loads ranging from 50 to 350 g.

An Origami-Based Soft Robotic Actuator for Upper Gastrointestinal Endoscopic Applications.

Soft pneumatic actuators have been explored for endoscopic applications, but challenges in fabricating complex geometry with desirable dimensions and compliance remain. The addition of an endoscopic camera or tool channel is generally not possible without significant change in the diameter of the actuator. Radial expansion and ballooning of actuator walls during bending is undesirable for endoscopic applications. The inclusion of strain limiting methods like, wound fibre, mesh, or multi-material molding have been explored, but the integration of these design approaches with endoscopic requirements drastically increases fabrication complexity, precluding reliable translation into functional endoscopes. For the first time in soft robotics, we present a multi-channel, single material elastomeric actuator with a fully corrugated design (inspired by origami); offering specific functionality for endoscopic applications. The features introduced in this design include i) fabrication of multi-channel monolithic structure of 8.5 mm diameter, ii) incorporation of the benefits of corrugated design in a single material (i.e., limited radial expansion and improved bending efficiency), iii) design scalability (length and diameter), and iv) incorporation of a central hollow channel for the inclusion of an endoscopic camera. Two variants of the actuator are fabricated which have different corrugated or origami length, i.e., 30 mm and 40 mm respectively). Each of the three actuator channels is evaluated under varying volumetric (0.5 mls-1 and 1.5 mls-1 feed rate) and pressurized control to achieve a similar bending profile with the maximum bending angle of 150°. With the intended use for single use upper gastrointestinal endoscopic application, it is desirable to have linear relationships between actuation and angular position in soft pneumatic actuators with high bending response at low pressures; this is where the origami actuator offers contribution. The soft pneumatic actuator has been demonstrated to achieve a maximum bending angle of 200° when integrated with manually driven endoscope. The simple 3-step fabrication technique produces a complex origami pattern in a soft robotic structure, which promotes low pressure bending through the opening of the corrugation while retaining a small diameter and a central lumen, required for successful endoscope integration.

Self-bending extrusion molding of distorted channels

Using an integrated profile extrusion and bending forming process with a streamlined extrusion die, a new self-bending extrusion molding technology is proposed with an axis-distorted variable channel. By designing the streamlined extrusion die structure of the distorted central axis, the metal was made to flow non-uniformly in the die cavity, thereby directly extruding a bent profile. The central axis of the streamlined extrusion die is described by a trigonometric function and a Gaussian function. A numerical simulation was applied to analyze the metal flow pattern, equivalent strain, and strain-rate distribution during the self-bending extrusion process. The influences of the extrusion velocity and the addition of a bearing on the self-bending deformation profiles were investigated. During the extrusion process, the streamline at the center of the billet could describe the overall flow of the metal in the die cavity, and the distance between the point on the end face of the die outlet and the center of the die outlet directly determined the degree of extrusion and bending. The greater the distance was, the larger was the degree of bending. The metal strain on the convex edge of the die was greater than that on the concave edge of the die, with the extruded profile always bending toward the concave edge. The strain rate of the metal changed the fastest near the most convex point of the die. As the extrusion velocity increased or more bearings were added, the radius of curvature of the extruded profile increased nonlinearly.

Robust Light Coupling in a Quadratically Bent Directional Coupler

Bending the axis of an optical directional coupler can result in phase mismatch between the evanescently coupled waveguides. Using a quadratic bending profile, we realize the phase mismatch with a sign flip scheme for robust light coupling between the waveguides. We derive an analytical solution for the coupling scheme and show its robustness against parameter variations. Beam propagation method solution of the scalar wave equation verifies the two-level analysis and the device robustness.

The ups and downs of the Missouri River from Pleistocene to present: Impact of climatic change and forebulge migration on river profiles, river course, and valley fill complexity

AbstractThe Missouri River is a continent-scale river that has thus far escaped a rigorous reporting of valley fill trends within its trunk system. This study summarizes evolution of the lower Missouri River profile from the time of outwash in the Last Glacial Maximum (LGM) until establishment of the modern dominantly precipitation-fed river. This work relies on optically stimulated luminescence (OSL) dating, water-well data, and a collection of surficial geological maps of the valley compiled from U.S. Geological Survey EDMAP and National Science Foundation Research Experience for Undergrads projects. Mapping reveals five traceable surfaces within valley fill between Yankton, South Dakota, USA, and Columbia, Missouri, USA, that record two cycles of incision and aggradation between ca. 23 ka and ca. 8 ka. The river aggraded during the LGM to form the Malta Bend surface by ca. 26 ka. The Malta Bend surface is buried and fragmented but presumed to record a braided outwash plain. The Malta Bend surface was incised up to 18 m between ca. 23 ka and ca. 16 ka to form the Carrolton surface (ca. 16 ka to ca. 14 ka). The Carrollton surface ghosts a braided outwash morphology locally through overlying mud. Aggradation followed (ca. 14 ka to ca. 13.5 ka) to within 4 m of the modern floodplain surface and generated the Salix surface (ca. 13.5 to ca. 12 ka). By Salix time, the Missouri River was no longer an outwash river and formed a single-thread meandering pattern. Reincision at ca. 12 ka followed Salix deposition to form the short-lived Vermillion surface at approximately the grade of the earlier Carrolton surface. Rapid aggradation from ca. 10 ka to ca. 8 ka followed and formed the modern Omaha surface (ca. 8 ka to Present). The higher Malta Bend and Omaha profiles are at roughly the same grade, as are the lower Carrolton and Vermillion surfaces. The Salix surface is in between. All surfaces converge downstream as they enter the narrow and shallow bedrock valley just before reaching Columbia, Missouri. The maximum departure of the profiles is 18 m near Sioux City, Iowa, USA, at ∼100 km downstream from the James Lobe glacial input near Yankton, South Dakota. Incision and aggradation appear to be driven by relative changes in input of sediment and water related to glacial advance and retreat and then later by climatic changes near the Holocene transition. The incision from the Malta Bend to the Carrolton surface records the initial breakdown of the cryosphere at the end of the LGM, and this same incisional event is found in both the Ohio and Mississippi valleys. This incisional event records a “big wash” that resulted in the evacuation of sediment from each of the major outwash rivers of North America. The direction and magnitude of incision from the LGM to the modern does not fit with modeled glacioisostatic adjustment trends for the Missouri Valley. Glaciotectonics likely influenced the magnitude of incision and aggradation secondarily but does not appear to have controlled the overall timing or magnitude of either. Glaciotectonic valley tilting during the Holocene, however, did likely cause the Holocene channel to consistently migrate away from the glacial front, which argues for a forebulge axis south of the Missouri Valley during the Holocene and, by inference, earlier. This is at least 200 km south of where models predict the Holocene forebulge axis. The Missouri Valley thus appears to reside in the tectonic low between the ice front and the forebulge crest. The buffer valley component of incision caused by profile variation could explain as much as 25 m of the total ∼40 m of valley incision at Sioux City, Iowa. The Missouri Valley also hosted a glacial lobe as far south as Sioux City, Iowa, in pre-Wisconsinan time, which is also a factor in valley excavation.

A Review of Numerical Simulations of Secondary Flows in River Bends

River bends are one of the common elements in most natural rivers, and secondary flow is one of the most important flow features in the bends. The secondary flow is perpendicular to the main flow and has a helical path moving towards the outer bank at the upper part of the river cross-section, and towards the inner bank at the lower part of the river cross-section. The secondary flow causes a redistribution in the main flow. Accordingly, this redistribution and sediment transport by the secondary flow may lead to the formation of a typical pattern of river bend profile. It is important to study and understand the flow pattern in order to predict the profile and the position of the bend in the river. However, there are a lack of comprehensive reviews on the advances in numerical modeling of bend secondary flow in the literature. Therefore, this study comprehensively reviews the fundamentals of secondary flow, the governing equations and boundary conditions for numerical simulations, and previous numerical studies on river bend flows. Most importantly, it reviews various numerical simulation strategies and performance of various turbulence models in simulating the flow in river bends and concludes that the main problem is finding the appropriate model for each case of turbulent flow. The present review summarizes the recent advances in numerical modeling of secondary flow and points out the key challenges, which can provide useful information for future studies.

Slope stability analyses at Agumbe Ghat section NH-169A with and without slope protection

Slopes along the highways in hilly areas are more prone to landslides and rockfalls. Slope failure predominantly occurs during monsoon and traffic gets interrupted. Slope stabilityanalysis is carried out to lessen the adverse effects of landslides and slope failures. One of the dangerous Ghat section in Karnataka is Agumbe Ghat. It has totally 14 hair pin bends. The work is focussed on slope stability carried out between 7th and 8th bend of Agumbe Ghat section which passes through NH-169A. The work reveals the analysis of slope stability with and without anchors. Slope catastrophes can be determined through suitable measurement of slope stability. Soil samples at the terrain are collected and tested in laboratory for important soil parameters. The bore log data has been collected and relevant data has been used for the analysis. The software used for analysis is GEO5 which helps to verify slope stability for critical circular or polygonal slip surfaces. Profile co-ordinate points have been surveyed and slope details have been collected from Google Earth,andwere used to plot 7th bend profile. This paper gives insight regarding,the set of anchors and effects on shear stresses along failure plain and stabilizing the slope effectively. Stability analysis were carried out by finding Factor of safety before and after adding anchors. It is found that the anchors increased the stability of slopes from 1.35 to 1.56.

Band Structure Extraction at Hybrid Narrow-Gap Semiconductor-Metal Interfaces.

The design of epitaxial semiconductor–superconductor and semiconductor–metal quantum devices requires a detailed understanding of the interfacial electronic band structure. However, the band alignment of buried interfaces is difficult to predict theoretically and to measure experimentally. This work presents a procedure that allows to reliably determine critical parameters for engineering quantum devices; band offset, band bending profile, and number of occupied quantum well subbands of interfacial accumulation layers at semiconductor‐metal interfaces. Soft X‐ray angle‐resolved photoemission is used to directly measure the quantum well states as well as valence bands and core levels for the InAs(100)/Al interface, an important platform for Majorana‐zero‐mode based topological qubits, and demonstrate that the fabrication process strongly influences the band offset, which in turn controls the topological phase diagrams. Since the method is transferable to other narrow gap semiconductors, it can be used more generally for engineering semiconductor–metal and semiconductor–superconductor interfaces in gate‐tunable superconducting devices.

I-shaped bent closed profiles with tubular shelves and calculation of the optimal layout of their composite sections

I-shaped bent closed profiles with tubular shelves are distinguished by a composite section and related to light steel thin-walled structures (LSTWS), which are characterized by high technical and economic indicators and mass demand in industrial and civil construction, which determines the relevance of the development of their new technical solutions. The aim of the work - to show that the characteristics of LSTWS can be further improved by forming profiles, combining straight and round outlines of closed and open circuits in a composite section. Methods. New technical solution, the originality of which is confirmed by patent examination, has been developed through experimental design and optimization and design calculations of I-shaped profiles. The calculation of the optimal bending layout of the composite sections of I-shaped profiles of horizontal billets from sheet blanks, identical and unequal in thickness, including bisteel modifications, is made. Results. The I-shaped bent closed profiles consists of two tubular shelves and one wall of double thickness. For its manufacture without welded, bolted or riveted joints, the outer pair and inner pair blanks are made along the entire length with serrated longitudinal edges, the teeth of which are staggered relative to each other and mutually bent in grooves after closing a bent profile along its shelves. The bends of the gear mounts increase the collapse thickness, provide an increase in the local stability and shear strength of the thin-walled elements, and also allow not to reduce the design sections. The calculation of the optimal layout of I-shaped profiles horizontal bend for bending showed that its strength is maximum when the ratio of the width and height of 1/5.2 and equal thicknesses of shelves and walls.