Sheet Plate Research Articles

Mechanical Properties of Brass under Impact and Perforation Tests for a Wide Range of Temperatures: Experimental and Numerical Approach.

The originally performed perforation experiments were extended by compression and tensile dynamic tests reported in this work in order to fully characterize the material tested. Then a numerical model was presented to carry out numerical simulations. The tested material was the common brass alloy. The aim of this numerical study was to observe the behavior of the sample material and to define failure modes under dynamic conditions of impact loading in comparison with the experimental findings. The specimens were rectangular plates perforated within a large range of initial impact velocities V0 from 40 to 120 m/s and in different initial temperatures T0. The temperature range for experiments was T0 = 293 K to 533 K, whereas the numerical analysis covered a wider range of temperatures reaching 923 K. The thermoelasto-viscoplastic behavior of brass alloy was described using the Johnson–Cook constitutive relation. The ductile damage initiation criterion was used with plastic equivalent strain. Both experimental and numerical studies allowed to conclude that the ballistic properties of the structure and the ballistic strength of the sheet plates change with the initial temperature. The results in terms of the ballistic curve VR (residual velocity) versus V0 (initial velocity) showed the temperature effect on the residual kinetic energy and thus on the energy absorbed by the plate. Concerning the failure pattern, the number of petals N was varied depending on the initial impact velocity V0 and initial temperature T0. Preliminary results with regard to temperature increase were recorded. They were obtained using an infrared high-speed camera and were subsequently compared with numerical results.

ON A PROBLEM FOR AN ELASTIC INFINITE SHEET STRENGTHENED BY TWO PARALLEL STRINGERS WITH FINITE LENGTHS THROUGH ADHESIVE SHEAR LAYERS

The article considers the problem for an elastic infinite sheet (plate), which is strengthened on two parallel finite parts of its upper surface by two parallel finite stringers with different elastic properties. The parallel stringers are located asymmetrically with respect to the horizontal axis of the sheet and deform under the action of horizontal forces. The interaction between the infinite sheet and stringers takes place through thin elastic adhesive layers. The problem of determining unknown shear stresses acting between the infinite sheet and stringers is reduced to a system of Fredholm integral equations of second kind with respect to unknown functions, which are specified on two parallel finite intervals. It is shown that in the certain domain of the change of the characteristic parameters of the problem this system of integral equations in Banach space can be solved by the method of successive approximations. Particular cases are considered, the character and behaviour of unknown shear stresses are investigated.

Embossment effect analysis on compression of mild steel using finite element methods

In the world of construction the use of mild steel is increasing due to the relatively light material and has great strength. This makes the producers start to innovate with the addition of reinforcement to get greater strength. Mild steel is formed from the grinding process on steel plate sheets. Because its thin thickness makes mild steel susceptible to buckling. The use of mild steel as a structural component requires great strength with the addition reinforcement. This research will discuss the effect of embossment width and dimensions on the compressive strength values of mild steel by the finite element method. This thesis uses MIDAS FEA finite element method program. The channel profile used is 75 mm x 34 mm x 5 mm x 0,65 mm with length 2000 mm. Model used is with and without stiffener and embossment distance variation from 15 - 150 mm. Boundary condition used hinge-roller, loading use axial load. The results of the analysis found that the greater the embossment distance, the greater the compressive strength produced. failure that occurs in a stiffener model that has embossment is lateral buckling

Optimization of Tensile-Shear Strength in the Dissimilar Joint of Zn-Coated Steel and Low Carbon Steel

The present study features analytical and experimental results of optimizing resistance spot welding performed using a pneumatic force system (PFS). The optimization was performed to join SECC-AF (JIS G 3313) galvanized steel material with SPCC-SD low carbon steel. The SECC-AF is an SPCC-SD (JIS G 3141) sheet plate coated with zinc (Zn) with a thickness of about 2.5 microns. The zinc coating on the metal surface causes its weldability to decrease. This study aims to obtain the highest tensile-shear strength test results from the combination of the specified resistance spot welding parameters. The research method used the Taguchi method using four variables and a combination of experimental levels. The experimental levels are 2-levels for the first parameter and 3-levels for other parameters. The Taguchi optimization experimental results achieved the highest tensile-shear strength at 5049.64 N. It properly worked at 22 squeeze time cycles, 25 kA of welding current, and 0.6-second welding time and 12 holding-time cycles. The S/N ratio analysis found that the welding current had the most significant effect, followed by welding time, squeeze time, and holding time. The delta S/N ratio values were 1.05, 0.67, 0.57 and 0.29, respectively.

Numerical Modelling of the Three-Roll Bending Process of a Thin Plate

Abstract The three-roll bending process is a simple procedure, commonly used in the industry, through which a cylindrical surface can be produced from a sheet plate. This process is mainly controlled through experience and it is described with the finite element method, except for a very few numerical and analytical investigations. The topic of this article is to present a numerical method, through which the curvature function along the rolling direction can be calculated. This article presents the proposed numerical method and its verification with the finite element method. The results of the two numerical methods are in good agreement.

Diagnostic signs of morphological and anatomical structure of Medicago falcata L. raw materials

Topiciality. Flora of Azerbaijan has a diverse vegetation cover and is rich in choice. However, today these sources of raw materials are not fully used to meet the needs of medicine and national economy. We conducted a resource reconnaissance survey of species of the genus Medicago in Azerbaijan and identified regions of mass growth. New natural habitats are located in different environmental conditions and it is possible to change the diagnostic features of the morphological and anatomical structure of plant materials, as well as the chemical composition. The combination of additional morphological and anatomical features allows a more accurate determination of the authenticity of the raw material. Aim. To study the diagnostic signs of morphological and anatomical structure of Medicago falcata L. raw materials from the flora of Azerbaijan. Materials and methods. Plant samples were fixed in a solution made in 0.1 M phosphate buffer (pH = 7.4), containing 2.5 % glutar-aldehyde, 2 % paraformal-aldehyde, 4 % sucrose, and 0.1 % picric acid. The fixed materials have been submitted to the Electron Microscopy Laboratory of the Azerbaijan Medical University for study by electron microscopy. Samples have been postfixed in 1 %-osmium tetraoxide solution prepared in phosphate buffer (pH 7.4) within two hours after being left in the same fixer for one day. Araldite-Epon blocks made from materials using general methods adopted in electron microscopy. The semi-thin (1-2 µm) sections from the blocks taken on a EM UC7 (Leica, Germany) ultramicrotome, stained with methylene blue, azure II, and basic fuchsin were observed under microscope Primo Star (Zeiss, Germany) and images of required parts were shot with EOS D650 (Canon, Chine) digital camera. Results and discussion. Multicellular trichome covered on both leaf sides. Adaxial epidermis a sheet plate have sinuous cells, and abaxial epidermis have differed slightly sinuous cells with clear-shaped walls. In leaflet anatomy of plant vascular bundles are of the collateral type. Stomatas are located from both sides of a leaf. Stomata belong to anisocytic structure. The epidermis of the stem consists of elongated thick-walled cells with anisocytic stomata. The calyx is densely covered by trichomes. The outer epidermis of cross-section of the keel petals cells is the wing horns cells form. And inner epidermis consists of oval cells. Mesophyll cells inside the leaf consist of loose spongy cells on the underside with several conducting bundles (dorsoventral). Conclusions . Morphological and anatomical studying of raw material Medicago falcata L. has shown, that there are prominent features of a structure:four large conductive bundles are located on the cross section of the stem at the corners of the ribs on two sides. Between angular conductive bundles, there are three conductive bundles, and the other two sides are located along one conductive bundle. Therefore, M. Falcata L. differs from M. Sativa L. The epidermis of the stem consists of elongated thickened-walls cells with anisocytic stomata. The indicated diagnostic morphological and anatomical characters could be used in the compilation of a monograph and in identifying plant materials on the raw material of Medicago falcata L.

The effect of plastic deformation on mechanical properties of aluminium matrix composites reinforced with 2D crystals

Abstract In this study, AA6061 matrix composites reinforced with multilayer graphene and MoS2 were analyzed. The composites were prepared by powder metallurgy using the spark plasma sintering and spark plasma texturing methods. Microstructure, physical and mechanical properties were investigated and compared with unreinforced AA6061 sinter and AA6061 sheet plate. The results showed that the application of spark plasma texturing positively influences the relative density and compressive yield strength of AA6061 matrix composites. Moreover, in composites with MoS2, significant differences in compressive yield strength between the centre and the edge of the sintered compacts were noticed. These differences are related to the formation of the MoAl12 phase as a result of the temperature gradient generated in the graphite die during sintering by the spark plasma texturing.

RISIKO CEDERA MATA PADA PEKERJA INDUSTRI PIPA BAJA

An eye injury is a trauma to the eye that can result in damage to the eyeball, eyelids, eye nerves and orbital cavity. Eye injuries can occur due to work processes in various industries, especially in the metal industry. PT. Bakrie Pipe Industry (BPI) is a metal industry that produces steel pipes by changing steel plate sheets into pipe shapes. One of the risks of work accidents in the production process is eye injury due to exposure to particles/gram of iron during the cutting process. This study aims to determine the risk factors for eye injury in workers in the Production Department of PT. Bakrie Pipe Industries, Bekasi, West Java. This study used a cross-sectional design involving all workers in the Production Department as research subjects, as many as 36 people. Data collection was carried out by interview and observation, then the data were analyzed using the chi-square test. The risk factors assessed were age, knowledge, attitude, noise and personal protective equipment against eye injury. The results showed that the risk factors for eye injury were knowledge (OR = 280.00; p value = 0,000), age (OR = 61.75; p value = 0,000), noise (OR = 39.00; p value = 0,000). , and the use of PPE (OR = 17.00; p value = 0.001). Increasing workers' knowledge about work risks is an effort that must be continuously carried out to avoid eye injuries, in addition to the necessity of using Personal Protective Equipment (PPE), and to carry out more intensive supervision.

The effect of plastic deformation on mechanical properties of aluminium matrix composites reinforced with 2D crystals

Abstract In this study, AA6061 matrix composites reinforced with multilayer graphene and MoS2 were analyzed. The composites were prepared by powder metallurgy using the spark plasma sintering and spark plasma texturing methods. Microstructure, physical and mechanical properties were investigated and compared with unreinforced AA6061 sinter and AA6061 sheet plate. The results showed that the application of spark plasma texturing positively influences the relative density and compressive yield strength of AA6061 matrix composites. Moreover, in composites with MoS2, significant differences in compressive yield strength between the centre and the edge of the sintered compacts were noticed. These differences are related to the formation of the MoAl12 phase as a result of the temperature gradient generated in the graphite die during sintering by the spark plasma texturing.

Asymmetry and shape in leaf blade red clover

The plastic variability, shape and asymmetry of the leaf plates of meadow clover (Trifolium pratense L) depending on various doses of fertilizer and soil cultivation methods were studied. A correlation between the index of plastic variability and the value fluctuating asymmetry was obtained (r = 0.23-0.63; p <0.05). Using the geometric morphometrics, the presence of directional asymmetry was confirmed, and a highly statistically significant variation in the shape of the sheet plate was obtained. In only one sample, a pure fluctuating asymmetry was obtained; in remain cases – a mixture of two types of asymmetry. The authors explain the effect of the declining developmental stability by a low dose of fertilizer, as well as a crop rotation scheme with a relatively low content of trace elements in the soil. A high dole of directional asymmetry verified the influence of genotypic variation on the asymmetry and shape of leaf blade and, therefore, a high dependence of phenotypic variation on the genotype.

Friction-Stir Spot Mechanical Joining between Hot-Dip 55% Aluminum–Zinc Alloy-Coated Steel Sheet and A5083 Aluminum Alloy Plate Using Conventional Punching

In this study, we fabricated a mechanical joining with spot friction-stirring between an aluminum alloy plate and an aluminum–zinc alloy-coated steel sheet; this was achieved by utilizing a conventional press-punching preprocess. In the preprocessing, a hot-dip 55% aluminum–zinc alloy-coated steel sheet was punched using a press and an inclined surface was generated at the wall of a punched hole due to shear droop. Subsequently, an A5083P-O aluminum alloy plate was positioned against it, and friction stirring was conducted on its rear surface. The hole was filled with the aluminum alloy to generate a mechanical interlock at the tilt of the wall. Further, we evaluated its cross tensile strength (CTS) and tensile shear strength (TSS) and obtained an average CTS and TSS of 368 kN and 1470 kN, respectively.

Fabrication and Piezoresistive/Piezoelectric Sensing Characteristics of Carbon Nanotube/PVA/Nano-ZnO Flexible Composite

Flexible sensors with a high sensitivity and wide-frequency response are essential for structural health monitoring (SHM) while they are attached. Here, carbon nanotube (CNT) films doped with various PVA fractions (CNT/PVA) and ZnO nanowires (nano-ZnO) on zinc sheets were first fabricated by functionalized self-assembly and hydrothermal synthesis processes. A CNT/PVA/nano-ZnO flexible composite (CNT/PVA/ZnO) sandwiched with a zinc wafer was then prepared by the spin-coating method. The piezoresistive and/or piezoelectric capabilities of the CNT/PVA/ZnO composite were comprehensively investigated under cyclic bending and impact loading after it was firmly adhered to a substrate (polypropylene sheet or mortar plate). The results show that the piezoresistive sensitivity and linear stability of the CNT/PVA films doped with 20%, 50%, and 100% PVA during bending are 5.47%/mm, 11.082%/mm, and 11.95%/mm and 2.3%, 3.42%, and 4.78%, respectively. The piezoelectric sensitivity, linear stability, and response accuracy of the CNT/PVA/ZnO composite under impulse loading are 4.87 mV/lbf, 3.42%, and 1.496 ms, respectively. These merits support the use of CNT/PVA/ZnO as a piezoresistive and/or piezoelectric compound sensor to monitor the static/dynamic loads on concrete structures while it is attached.

Comparative analysis of anatomical structure of wood plant leaf under exposure to volatile organic compounds

Industrial enterprises of thermal power engineering, fuel, chemical and petrochemical industry, mechanical engineering, non-ferrous metallurgy are sources of volatile organic compounds, the emissions of which can now reach a significant amount due to changes in technological processes. Studying the effect of volatile organic compounds on changes in anatomical parameters of a plant sheet is a little-studied aspect compared to exposure to oxides of nitrogen, carbon, sulfur, ammonia, heavy metals. The aim of the work was therefore to study the anatomical features of the tree leaf as adaptive features under the influence of emissions from industrial plants containing selected volatile organic compounds. Time preparations of the cross section of the leaf were used for anatomical studies. The thickness of the epidermis, the mesophyll, the number of upper and lower epideric cells, the number of wellheads and their width, the size of the conductive beam, the palisadity coefficient (the ratio of the thickness of the columnar mesophyll to the sum of the thickness of the columnar and spongy mesophyll) and the oral index (the ratio of the number of wellheads to the total number of epidermal cells). Impressions of the upper and lower epidermis were made with colorless varnish. As objects for studying the features of the anatomy of the leaf were chosen the leaves of a number of species of wood plants, which are among the most common near the industrial enterprises of the city of Gomel: drooping birch Betula pendula Roth., maple holly Acer platanoides L. Leaf samples were taken in the zone of influence of emissions of industrial enterprises containing xylenes and butylacetate (JSC «Gomel plant leaves and normals»), as well as benz(a)pyrene (heat and power plant). As a result of the studies, the cells of the columnar mesophyll in the birch leaves were found to have the greatest sensitivity to organic toxicants (xylenes and butylacetate) at the end of the vegetation compared to the maple holly leaves and the parameters of the spongy mesophyll. Drooping birch was characterized as the species in which sclerenchyma in the region of the conducting bundle under technogenic conditions was the thinnest, especially at the beginning of the growing period. Also in birch, when growing around industrial plants, there was a decrease in the number of cells of the upper and lower epidermis compared to control in most variants, especially the upper epidermis in samples exposed to xylenes and butylacetate at the beginning of the growing period. Maple holly showed a more intense decrease in the number of oysters and the value of the oral index compared to control than birch. When exposed to the benz(a)pyrene of heat and power plant emissions, both wood plant species studied showed an increase in mesophyll palisadity coefficient during the most intensive sheet plate formation processes. The conducting bundles of the studied wood plants were characterized by a decrease in the largest diameter when growing under technogenic conditions, most intensively in may at the maple holly. In general, the study of anatomical features of leaf plates of wood plants when growing in the area of exposure to volatile organic compounds of industrial emissions is great interest in terms of understanding the adaptive mechanisms of plants to stress conditions. The seasonal dynamics of changes in anatomical parameters in the birch leaf was characterized by a decrease in their values in most cases in september compared to may in the territory of the industrial enterprises under consideration. In maple holly approximately in equal amounts there was both a decrease and an increase in anatomical parameters between may and september.

Designing of a BLDC motor bench

This paper deals with designing and development of a bench for the test of a brushless DC motor. The bench contains a hydraulic circuit, which provides a controllable load for the motor. The hydraulic system is equipped with a hydraulic pump and choke valve and a manometer. The mechanical connection between the hydraulic pump and the BLDC motor is designed with two clutches and structure of two sheet plates. The bench contains a torque meter, which is built between the two shafts of the motor and pump. The system can determine rotational speed, torque, current and voltage with respect of the load.

Upsetting calculation of edge on plate during their assembly

The relations for calculating of the deformation and force upsetting modes of edge on the plate (sheet) during their assembly are proposed. The state of viscoplasticity of the material under isothermal heating is assumed. The discontinuous fi eld of travel speeds is used. The calculation of the loss of continuity of the workpiece material is given.

Laser Treatment for Strengthening of Thin Sheet Steel

This paper presents the results of computer simulations and experimental studies, aiming to increase the mechanical strength of sheet metal parts manufactured from high‐quality structural carbon steel by means of local laser processing. The effects of laser processing on the strength of steel sheet plates and their ability to resist bend load after laser treatment were studied. The results of bending experiments and computer simulations of elastoplastic deformation establish that local laser processing with surface melting can be used to increase the mechanical strength of structural elements made from thin sheet steel C22E and to decrease its deflection under similar workload, as an alternative to the application of complex geometric shapes, additional strengthening elements, or heat treatment.

Effect of Local Heating on the Mechanical Characteristics of Repaired Automotive Panels

Flame straightening is a technology process used to eliminate deformations. This method relies on local heating of the material to correct geometry or damaged parts. In the local automobile services its main use is for repairs of less critical deformed components. The maximum temperature and thermal gradient, heating time, cooling rate and number of heating cycles affect the mechanical properties since local heating can alter material microstructure. The aim of this research was to determine the mechanical characteristics of thin steel plates repaired by local heating associated with plastic deformation (similar to hot working) and cold straightening (similar to local cold working) for automotive side and door panels made of structural steel. Thin sheet plates, 0.9mm thickness, were deformed by impact and repaired by local heating using the flame and induction heating then plastically deformed while hot as well as straightened without heating. The heat repaired samples were studied by light microscopy to determine microstructure change and samples were tensile tested to determine their mechanical characteristics. Local excessive grain growth generates anisotropy, the assembly behaves as a composite material with regions that show significant plastic deformations while others little or no deformations at al. Without procedures adjusted to each material repairs involving heating are to be avoided, cold working should be employed when replacement is not possible.

Pengaruh Sudut Punch dan Ketebalan Pelat terhadap Springback pada Bending V

The bent plate is inseparable from the phenomenon that determines the size of the resulting bending angle. This phenomenon is called springback. Springback is a condition that occurs on a sheet plate when bending is done where after the punch load is removed the bent sheet plate has a tendency to return to its original form. Mini brake bending V tool with a hydraulic jack system produces springback of 1-5 degrees for punch angle 85 ° radius 2.5 mm and carbon steel material St 42 at thickness 3, 4 and 5 mm. Therefore, this study was conducted to find out how the influence of punch angle and plate thickness on springback. The limitation problem in this study is the thickness of the plates used 2 and 4 mm. The type of method used is bending V bottoming with a die angle of 90 °, the punch angle used is 80, 85, and 90, the punch radius used is 2, 4 and 6 mm, and the plate material used is carbon steel. The research method starts from designing die set, punch and die test aids, and making test specimens, then bending test, bending angle and springback measurements are carried out. Based on the research conducted, the greater the punch angle, the smaller springback produced and the thicker the plate, the smaller springback produced tends to be smaller, where the smallest springback is obtained on a plate thickness of 6 mm with a punch angle of 90 ° 4 mm radius obtained -0.31o.

Desain Konstruksi Press Tool Sebagai Alat Bending Bentuk V Dengan Garis Bending Max. 300mm

Nowadays, the process of metal forming in the machining industry and welding workshop is developing very rapidly especially in the plate bending process. The bending process is the formation of metals which generally use plates or rods of both ferrous and non-ferrous metal materials by bending, which in the bending process will cause stretching or stretching on the neutral plane axis along the bending area and produce a straight bend line. The use of appropriate technology machines has been widely used to increase productivity, efficiency, and effectiveness in the production process for community businesses, especially those in the regions. One of the appropriate technologies that might be applied in the bending process is a hydraulic jack press that is equipped with a press tool. Press tool is one type of product forming, cutting and bending tools from the basic material of sheet plates whose operations are using a press tool. The results of the design of press tool bending tool V have a length of 300 mm bending line, 33 mm bending width, 110 mm spring height, free step distance of 19 mm. The punch angle used is 85⁰ with the punch radius used is 1.5 mm while the die angle is 85⁰. The selected punch and die material is Steel AISI 1045 HV HR.

Designing and Manufacturing the Press Tool of Air Bending V Brake

Nowadays, the metal forming process in the welding machinery and machinery industry is developing very rapidly, especially in the bending process. The buckling process is a metal formation which generally uses sheet plates or rods from both ferrous and non-ferrous metals by bending, which in the bending process will cause a stretching or stretching on the neutral axis of the field along the bending area and producing a straight bending line. Appropriate technology machines have been widely used to increase productivity, efficiency, and effectiveness in the production process for community efforts. One of the appropriate technologies that can be applied in buckling is a tool equipped with a press tool. Press tool is one type of tool for the formation, cutting and bending of products from the base material of sheet plates whose operation uses a press machine. In this study, a V brake bending tool has been produced which has a capacity that is bending line length 300 mm, bending width 33 mm, spring height 110 mm, free step distance 19 mm, spring load received 263,820 N and material capacity that can be bent is a thickness of 3 mm, the punch angle used is 85⁰ with a punch radius used which is 1.5 mm while the die angle is 85⁰