Steel Rods Research Articles

Multi-objective holistic optimization method for CR SRPS based on cross-scale failure simulation of composite to improve oil recovery benefits

A carbon/glass hybrid fiber continuous sucker rod (CR) with lower specific gravity, better corrosion resistance and higher strength was developed to replace the steel rod in oil production. This paper proposes a multi-objective holistic optimization method of sucker rod pumping system (SRPS) using CR for improving oil recovery benefits. Firstly, based on the cross-scale failure criterion and finite element simulation, a judgment index for fatigue damage of CR and their joints under multiple loads, namely fatigue strength margin (FSM), is constructed, and used as a life characterization parameter of SRPS. After it is verified with liner correlation between the production cycle and FSM of realistic SRPS, FSM in addition to energy consumption and the production rate are included in the optimization objectives. Then, a multi-objective optimization model with the holistic parameters of CR SRPS as the decision variables is established. To improve the efficiency of solving the model, a hierarchical enumeration algorithm with the strategy of reducing the optimization space repeatedly by weakened constraints is presented. Finally, the proposed method was applied to the design of CR SRPS for realistic oil wells, its effectiveness and superiority are verified by the application effect and comparison results with current methods.

Experimental Investigation of Electric Arc Welding Variables on the Corrosion Behaviour of Steel Welds in Acidic Medium

This work investigated the effects of power input and welding speed on the corrosion rate of low carbon steel welds in one molar tetraoxosulphate (VI) acid (H2SO4) solution. Locally available low carbon steel rod (Ø12mm) used for this study was cut into twenty four samples Ø12mm × 50mm with the aid of hacksaw for both plane face and double V shape. The samples were further processed through machining to get twelve samples for plane face and double-V edge shape respectively. Electric arc welding was used for welding the samples to produce six welded joints for each of plane face and double V shape at different power input and welding speed. Weight loss method was employed to evaluate the corrosion rate of the welded joints in the tested medium. It was discovered from the study that welding speed and power input have significant roles to play in either lowering or increasing the corrosion rate of the low carbon steel welded joints in one molar tetraoxosulphate (VI) acid solution. The plane face and double-V edge low carbon steel welded joints corrodes less at power input and welding speed of 16.5kW and 12cm/min respectively. Their corrosion rate is more aggressive at higher power input and welding speed.

Eddy Current Testing Methods and Design for Pipeline Inspection System: A Review

Non-destructive testing and complex systems integration are commonly used in transportation, aircraft, automotive, manufacturing, petrochemical, and defence. Eddy current testing (ECT) is a common non-destructive evaluation technique, especially in the coating, nuclear, and oil and gas industries. However, the eddy current testing method must continue to focus on the probe’s construction and application. It ascribed noisy data to inadequate detection and a severe false alarm problem. Nonetheless, only few academics have elaborated on the intelligent ECT crack detection method. This study provides an overview of the eddy current testing technique and the probe structure design elements that influence fracture detection accuracy. The first section describes the Eddy current testing by encircling coil system for a differential probe (ECDP) and an encircling coil for an absolute probe design (ECDP). The explanations focus mostly on the probe’s creation and detection in Rotating electromagnetic field eddy current (RoFEC). The advantages and disadvantages of eddy current testing surrounding probes are analysed. In addition, a summary of prior studies investigating testing samples of ferromagnetic pipe, steel rod, and wire rope is presented. The second segment focuses on Eddy current testing employing a Giant Magnetoresistance (GMR) sensor system, with a particular emphasis on sensor arrays, GMR, and conventional eddy current coils for crack identification. Finally, a comprehensive overview of eddy current testing methods and design for non-destructive pipeline inspection systems is presented.

Specific Features of Corrosion-Fatigue Fracture of Steel and Hybrid Pump Rods

Specific Features of Corrosion-Fatigue Fracture of Steel and Hybrid Pump Rods

Glulam Beam-to-Column Connection with Coupled Steel Rods with Screwheads: Concept and Experimental Verifications

The bolted connections with slotted-in steel plates are basic beam-to-column connections of modern post-and-beam timber building structures. However, due to significantly pinched rotational behaviors, the moment resistance of such connections are usually ignored in design. In this study, the connection-level moment resistance is enabled for modern glulam frame structures with an innovative connection design. A pair of long steel rods with screwheads is designed to generate a force couple at the sides of the connection. The proposed connection could be considered as the key lateral force resisting component, indicating a significant reduction of lateral braces and shear walls. Specimens of the target connection were carefully designed and tested in the lab to obtain their mechanical properties and failure modes. Finite element models were established and calibrated according to the tested data. The moment-rotation curves of the new connection could be easily estimated through a fitted formula. Moreover, the suggestions to improve the proposed connection is also discussed based on the observed damage modes. Results show that the new connection could be treated as rigid moment-resisting connections while the ductility could be further improved.

The Effect of Storage Conditions on the Strength Characteristic of Glulam Beams

Despite many outdoors applications, the number of works aimed to determine the effect of changing conditions on the properties of glulam beams, in particular those produced in non-standard arrangements, is few. Therefore, the aim of this study was to assess changes in flexural strength properties (MOE, MOR) of the beams stored for 30 months in varying conditions. Analyzed variants of pine GLT beams included five-meter-long structural elements reinforced with oak timber, high-quality pine timber and steel rods stored both in the roofed shed outdoors and inside the climatic chamber. Moisture content of the beam varied significantly depending on the placement of the sensors (on the surface or inside the beam). The average modulus of elasticity after 30 months of storage decreased by approx. 7% compared to initial values. The results varied depending on both the assumed beam arrangement and the applied conditions.

Experimental-numerical analysis to determine the efficiency of industrial lubricants in wire drawing process

Drawing is a manufacturing process that consists of indirect deformation by pulling the material through a tool with a conical geometry. The process is usually performed at room temperature (cold forming), so the selection of effective lubricants is critical. If lubrication is inadequate, there is a high risk that both, tool and the manufactured wire, will fail. In this study, annealed AISI 1020 steel rods were drawn and the effectiveness of three different industrial lubricants was tested. During the process, the drawing force values were recorded and used to determine the friction coefficient that developed under each lubrication condition. Numerical simulations were performed to further understand the process. Based on the experimental and numerical results, qualitative and quantitative analysis were performed for each condition. Among the different lubricants used in this study, zinc stearate showed the lowest value for drawing force, 18.8 kN, followed by Lub A and B with values of 20 kN and 20.6 kN, respectively. The numerical models showed excellent approximation to the force values determined in the tests. The values for the coefficient of friction obtained by both the numerical analysis and the empirical model indicate that zinc stearate has the highest lubricating effect among the lubricants focused on this study.

The Magnetoelastic Contribution to the Steel Internal Damping.

In this paper, the steel internal damping due to both the thermoelastic and the magnetoelastic phenomena has been investigated through a formulation based on thermodynamical potential joints with a hysteretic damping model. With the aim of focusing on the temperature transient in the solid, a first configuration has been considered, which is characterized by a steel rod with an imposed alternating pure shear strain in which only the thermoelastic contribution was studied. The magnetoelastic contribution was then introduced in a further configuration, in which a steel rod in free motion was subjected to torsion on its ends in the presence of a constant magnetic field. A quantitative assessment of the influence of the magnetoelastic dissipation in steel has been computed according to the Sablik-Jiles model by giving a comparison between the thermoelastic and the prevailing magnetoelastic damping coefficients.

Plasma generation in water using a compact electrode with a semi-covered structure

This is a fundamental study on a design of a plasma reactor and its electrical and hydrodynamic properties. In this study, the electrode structure suitable for this method and its installation position in the reactor were examined. The structure uses a ceramic tube and a stainless steel rod, making it possible to use high conductivity water. The pressure inside the reactor was measured, and the electrode was placed at a position where cavitation was minimum. Then, the cavitation was observed in a sample of water with a conductivity of about 10 mS m−1, and the plasma was also observed. It was found that about 20% of the total power input between the electrodes was used for plasma generation. The hydrogen peroxide concentration proportional to the input power was observed, and a concentration of about 5.5 mg l−1 was obtained at an input power of 20 W when the volume of water was 1.8 l. And also the energy yield of H2O2 generation was 5.9 g kWh−1.

Ultra-low cycle fatigue life prediction of assembled steel rod energy dissipaters with calibrated ductile fracture models

In recent decades, various bar-typed miniature energy dissipaters with buckling restrained mechanisms have been proposed for seismic mitigation of engineering structures. The recently proposed assembled steel rod energy dissipater (ASRED), incorporating equally divided tubes as filler components, have shown plump hysteretic loops and remarkable fatigue performance. For such miniature dissipaters with varied dimensions, its ultra-low-cycle fatigue (ULCF) life is correlated with the geometrical dimensions. However, no research concerning this issue has been found. To enable the fracture prediction of ASREDs under various loading situations, numerical models integrated with the ductile fracture model were established in this paper. A newly proposed constitutive model and the famous combined hardening model were both employed in the numerical models to comparatively investigate the key factors affecting the accuracy of the fracture prediction. Moreover, the possible influence of Lode angle was also investigated by employing two different ductile fracture models, namely, the cyclic Bai-Wierzbicki model (CBWM) and the cyclic void growth model (CVGM). Seven specimens with different lengths and loading protocols were simulated, and the results show that the strain amplitude distributes unevenly in the ASRED and increases cycle by cycle at the fixed ends, which leads to the necking-induced failure mode. Using the fracture model of CBWM, numerical simulations that considers the influence of strain amplitude could successfully predict the fracture of all specimens. The dissipaters behaved approximately in an axially loaded state throughout the entire fatigue life, therefore the influence of the Lode angle was negligible, and the fracture predictions given by the CVGM are same with that by the CBWM. Based on a comprehensive analysis of the extended numerical investigations, an improved configuration for ASRED is proposed.

Analytical, simulation, and experimental verification of ultrasonic thermometry technique

When an ultrasonic wave travels through a material, such as a rod, the propagation and reflection characteristics are a function of the medium properties. When a material is heated, its mechanical properties, density, and volume change with respect to the medium, and so does the speed of sound. By using ultrasonic waves, the difference in speed can be used to estimate the temperature of a solid material. This technique is known as ultrasonic thermometry. The central hypothesis is that the wave travels slower as the temperature increases. To explain the underlying scientific principles of the technique, we developed analytical methods for estimating the time delays associated with varying temperatures. Time delay curves were developed by repeating the procedure at various temperature values using the corresponding mechanical and thermal properties at those values. That is, young’s modulus, Poisson’s ratio, and the thermal expansion coefficient were considered based on the temperature values. Additionally, this study outlines a numerical study on the temperature dependence of ultrasonic waves propagating through a 304L stainless steel rod using COMSOL software. Numerical results concur with analytically derived estimations, showing a decrease in the wave propagation speed and the wave amplitude as the temperature changes between 20 °C, 100 °C, 300 °C, and 500 °C. The simulated time delays agree well with the analytical calculations, and the displacement–time curve shift occurs due to the mechanical properties and thermal expansion effect. To confirm the accuracy of the technique, additional experiments were conducted on physical samples of 304L stainless steel. However, the frequency was modified to 2.25 MHz to increase spectral resolution given the limited temperature range possible of 25 °C–130 °C. We conclude by indicating that, due to the high accuracy of the analytically derived equations, the equations and technique developed has the potential to be utilized for time delay curves of other metals, in addition to 304L stainless steel.

Impingement jets on a confined assembly of rotating hot cylinder covered by a surface porous layer

Thermal stresses encountered in the production of steel rod is a challenging problem arising from the irregular temperature distribution along the circumference of the rod. This study investigates the cooling process of a hot cylinder with a uniform surface temperature. The concept of the problem is a rotating cylinder immersed in an annular porous medium under the impact of two impinging jets. The jets are confined and act upward and downward. The rotational speed of the cylinder, the eccentricity of the surface porous layer and its Darcy number and Reynolds number are varied to organize the feasibility of the suggested problem. The parameters are controlled to be within the laminar mathematical system, which is solved computationally using the finite element method. The results show a promising role of the porous surface layer as it raises the Nusselt number, where it elevates 78% greater than a bared cylinder for a Darcy number Da = 10−2 and a Reynolds number Re = 400. It was found that although the rotation of the cylinder reduces the Nusselt number, it contributes highly to the uniformity of the surface temperature of the cylinder. It was found also that the eccentricity of the porous layer increases the average Nusselt number by 28% for Re = 300 and Da = 10−2. The porous layer and the cylinder rotation increase slightly the pressure drop.

The effects of extrusion ratio and heat treatment on microstructures and tensile properties of a powder metallurgy Fe–22Mn steel

Powder metallurgy Fe–22Mn (wt.%) steel rods were fabricated by powder compact extrusion followed by heat treatment, and their microstructures and tensile properties were investigated. The microstructure of the as-extruded rods consisted of γ-austenite, ε-martensite, α'-martensite and a dispersion of ferrous manganese oxide (FMO) particles. By increasing the extrusion ratio from 9:1 to 16:1, the volume fractions of γ and ε increased significantly, while that of α' decreased significantly, which is due to more Mn atom diffused into the γ phase and improved its stability. This situation led to a significant decrease in yield strength without much change of the tensile strength and ductility. γ→ε and ε→α' transformations occurred during plastic deformation, resulting in a strengthening of the strain hardening capacity. The γ→ε transformation occurred only when the strain was <0.1, and beyond this strain, the volume fraction of γ decreased to a level that would not allow further phase transformation in γ. Annealing at 1200 °C for 1 h makes Fe atoms undergone segregation in FMOs, causing an obvious decrease of the hardness and Young’ s modulus of the FMO particles to a level lower than that of the matrix, which brings more severe damage to the ductility of the material.

Effects of functional poly(ethylene terephthalate) nanofibers modified with sericin-capped silver nanoparticles on histopathological changes in parenchymal organs and oxidative stress in a rat burn wound model

In this study, it was aimed to investigate the effect of a poly(ethylene terephthalate)-g-poly(hydroxyethyl methacrylate) (PET-g-HEMA) nanofiber wound dressing modified with sericin-coated silver nanoparticles (S-AgNPs) on internal organs, oxidative stress, and biochemical parameters. To establish a burn model, the backs of anesthetized rats were shaved and then third-degree burns were created with a round-bottomed stainless steel rod 2 cm in diameter kept in 100 °C water for 20 seconds. The wounds of the negative control group (G1) were covered with standard bandages; the wounds of the positive control group (G2) were covered with silvercel, used as burn wound material; and the wounds of the experimental group (G3) were covered with PET-based dressing material. Histopathological changes in organs (liver, kidneys, heart, pancreas, lungs), total oxidant status (TOS), total antioxidant status (TAS), nitric oxide (NO), and biochemical parameters (serum aspartate aminotransferase [AST], alanine aminotransferase [ALT], gamma glutamyl transpeptidase [GGT], creatine kinase, lactate dehydrogenase [LDH], total protein, albumin, globulin, urea) were examined. Compared with the G1 group, plasma AST, ALT, and GGT levels were found to be significantly decreased in G2 and G3 (P&amp;lt;0.001). Plasma TAS was found to be significantly increased in G2 and G3 compared to G1 (P&amp;lt;0.05). Compared to the G1 group, degenerative and necrotic changes in the liver, kidneys, and pancreas were found to be significantly reduced in G2 and G3 (P&amp;lt;0.05). In conclusion, this work demonstrates that the synthesized PET-based wound dressing material has the capacity to be used commercially.

Structural Assessment and Strengthening of a Historic Masonry Orthodox Church

This study provides insight into the structural assessment, diagnosis, and strengthening of the medieval church of Tazlău Monastery in Piatra Neamț, Romania. The first part of the paper briefly presents the wider context of strengthening and preserving heritage churches and monastic buildings and describes the architectural setting and the structural features of the traditional Romanian Orthodox churches. The second part of the paper is a case study related to the rehabilitation of a medieval heritage church, which is the paramount building of a larger monastic complex. Erected in 1496, the church of the Nativity of the Blessed Virgin Mary closely follows the medieval traditional Orthodox patterns from both architectural and structural points of view. Structural assessment and diagnosis revealed that degradations were induced and developed throughout the life of the structure due to approximately 24 earthquakes (estimated at over 6.0 magnitude) having endangered the structural safety of the building and the mural iconography. After the structural diagnosis, a combined and complex method of strengthening consisting of both grouting and introducing steel rods in vertically drilled galleries along the entire height of the walls was selected. The main advantage of applying this combined strengthening strategy was a remarkable enhancement of the structural seismic performance of the church building.

Application Research on Nb Microalloying of High-Carbon Pearlite Bridge Cable Wire Rods

The application of Nb microalloying to high-carbon pearlite bridge cable wire rod steel has always been controversial, especially in the actual production process, which will be affected by the cooling rate, holding temperature and final bonding temperature. In this paper, the experimental characterization, finite element simulation and phase diagram calculation of the test steel were carried out, then the microstructure and properties of different parts of Nb microalloying of bridge cable wire rods were compared and analyzed. The phase transition interval of pearlite during the water-cooling process of bridge cable wire rods is increased due to the refinement of austenite grains, and the significant increase in the end temperature of the phase transition makes the average interlamellar spacing of pearlite increase. The cooling rate of different parts of bridge cable wire rods simulated by Abaqus has little difference. At the same time, Nb microalloying effectively increases the proportion of low-angle grain boundaries, so that the overall average misorientation representing the surface defects is reduced. This helps to reduce the surface energy and increase the stability of the microstructure. Combined with the mechanical properties of microtensile rods, it is found that the grain refinement effect of Nb is greater than that of coarsening interlamellar spacing during hot rolling deformation in actual production, which makes the tensile strength at the 1/4 section increase significantly. The overall tensile strength and area shrinkage of the steel wire have also been effectively improved.

Kajian Perilaku Kuat Geser Tanah Terhadap Penambahan Serat Karung Goni

Soil improvement is a method to improve the physical and mechanical properties of soil that are not good. Soil improvement methods include chemical, mechanical, hydraulic, and reinforcement methods for example by adding geosynthetic sheets/fibers or steel rods. However, the use of these methods is relatively quite expensive from the aspect of the materials used when applied to small-scale volume work. This research tries to examine the behavior of the soil that is given the addition of jute sack fiber, especially to changes in shear strength/soil shear strength parameters. Jute sacks are an alternative material as a substitute for fiber of the Geosynthetic type, jute sacks have a rough texture made of jute fiber, where jute fiber is the second most used natural fiber after cotton. Jute fiber itself can be taken from the bark of the bast fiber tree. Jute itself is an environmentally friendly fabric because it is made from bio-degradable fibers and is included in fabrics made of 100% plant fibers. The percentage of jute fiber used was 0.25%, 0.50% and 0.75% of the dry weight of the soil with variations in length of 1.5 cm, 2.0 cm and 2.5 cm. The sample of soil tested is sandy type from the permanent residential area of Tondo, Mantikulore sub-district, Palu, Central Sulawesi. The addition of fiber has more effect on changes in the value of the soil friction angle than the value of cohesion. Jute fibers with lengths of 1.5 cm and 2.5 cm at percentages between 0.25% and 0.75% tend to increase, but at 2 cm length tend to decrease the value of shear strength. Fiber length and burlap percentage influence each other in increasing and decreasing the value of soil shear strength

Development of Experimental Core Configurations to Clarify keff Variations by Nonuniform Core Configurations

The fuel debris generated by the accident at the Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Plant is expected to have not only heterogeneous but also nonuniform compositions. Similarly, damaged fuel assemblies remaining in the reactor vessels also have nonuniform configurations due to some missing fuel rods. These nonuniformities may cause changing neutron multiplication factors. The effect of nonuniformities on the neutron multiplication factor is clarified by computations, and the possibility of experimentally validating the computations used for criticality management is being investigated. For this purpose, in this study the criticality effects of several core configurations of a new critical assembly, STACY, of the Japan Atomic Energy Agency with nonuniform arrangements of uranium oxide fuel rods, concrete rods, and stainless steel rods were studied to confirm benchmarking potential. The difference in these arrangements changed the neutron multiplication factor by more than 1 $. We confirmed that changes in local neutron moderation conditions and the clustering of specific components caused this effect. In addition, the feasibility of benchmark experimental cores with nonuniform arrangements is evaluated. If benchmarking of such experiments could be realized, it would help validate calculation codes and develop criticality management methods by machine learning.

Identification of Soil Layers and Properties by Vibration Measurements during Dynamic Penetration Testing

Abstract A common geotechnical site investigation method in Sweden is soil-rock sounding. A steel rod is driven into the ground by a percussion drill and different drilling parameters are recorded. The penetration speed and pushing force are used to determine the soil layer profile, the presence of boulders, and the depth to bedrock. This article describes a novel concept where the ground vibrations generated by the drill bit are measured by a geophone at the ground surface to gain more information about the penetrated material. The results of vibration measurements are analyzed in terms of frequency spectra, spectrograms, and two new parameters called “spectral concentration” and “overtone ratio.” These results show that the method can identify the depth of the groundwater table, distinguish boulders from penetration into bedrock, and possibly identify silt, sand, and gravel layers. More data are needed in different soil types to verify the reliability of the concept.

A time reversal metasurface for mimicking the cocktail party effect

The cocktail party effect is the capability to focus one's auditory attention on particular audio sources while ignoring other audio sources. We propose an experimental setup reproducing the cocktail party effect by designing a time dependent metasurface composed of independent active mirrors. Each active mirror is a programmable acoustical unit cell capable of hearing, computing, and emitting acoustic signals: each of them acts as a convolution filter. The proper metasurface temporal filters configuration allows us to establish acoustic communication between groups of individuals immersed in a noisy environment: a MU-MIMO acoustic system. The experiment consists in recording a set of Green's function between Ne emitters and Nj active mirrors, and a second set of Green's functions between the Nj active mirrors and Nr receivers. To increase the spatio-temporal degrees of freedom (Lemoult et al., PRL 103 2009), we place a forest of steel rods between the active mirrors, the emitters, and the receivers. These data are then used to compute each active mirror's temporal filter using time reversal properties to establish a predefined MU-MIMO configuration. The Ne emitters now emits simultaneously uncorrelated noises. These signals propagate through the disordered medium to the metasurface, then each active mirror hears, convolutes with his filter and emits another signal, which propagates back through the disordered medium towards the Nr receivers. In the end, we establish a correlation matrix by comparing emitted and received signals.