Rod Material Research Articles

Failure analysis of a sucker rod fracture in an oilfield

The sucker rod was fracture after 729 days’ service in an oilfield. The fracture position is located at the welding seam that is connecting the sucker rod’s upsetting end and the polished rod end. The failure causes were analyzed by the nondestructive test (NDT) of penetration detection, direct-reading spectrometer, tensile strength test machine, impact test machine, vickers hardness tester, optical microscope (OM), macroscopic fracture morphology, scanning electron microscopy (SEM) in this paper. The process of the fracture is under cyclic loading and the stress concentration, the sucker rod’s outside weld was brittle cracking in the first fracture at the beginning. Then the crack in first facture is passed to the inside welding residual, which is corresponding to the source area of the second fracture. Finally, the crack in the second fracture propagation along the weld seam and connected with the first fracture surface lead the rod broke completely. The causes of sucker rod breaking for the sucker rod did not meet the requirements of the HL grade rod material and the friction welding defects.

Synthesis of plasmonic gold nanoparticles supported on morphology-controlled TiO2 for aerobic alcohol oxidation

Abstract In the present research study, we report the synthesis of nano-sized gold (Au) particles immobilized on TiO2 support material. The morphologies of TiO2 support material was tailored and tuned to be rod, tube and microporous materials. The effect of plasmonic gold nanoparticles (NPs) deposited on different morphologies of TiO2 was studied. The prepared catalysts were characterized by various characterization techniques in order to have a detailed insight on the textural properties, morphology and electronic state of the material via UV–vis spectroscopy, N2 physisorption analysis, Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). We tested the controlled oxidation of benzyl alcohol to benzaldehyde using molecular oxygen at 373 K under atmospheric pressure. The results obtained from the thermal reaction conditions were compared with those performed under visible light irradiation (λ > 420 nm) at 373 K. Among all, Au/TiO2 nanorod catalyst displayed the superior performance of 33% yield in the absence of light and 55% yield of benzaldehyde with an external quantum efficiency of 3.4% under visible light irradiation (λ ≥ 420 nm) at 373 K for 4 h. The enhanced catalytic performances were attributed to the Au-LSPR phenomenon and a plausible reaction pathway has been discussed involving the generation of hot electrons during the course of reaction.

Modelling and analysis of different connecting rod material through finite element route

Abstract In general connecting rods are manufactured by using carbon steel; nowadays aluminium alloys are best alternative material to produce connecting rod. Aluminium alloys are less weight and absorb high impact strength since it is best suited for high speed engine in the bike. In this work focused on to analysis of three different aluminium alloy materials as AA2014, AA6061 and AA7075. FEA analysis was carried out through ANSYS software for selected three materials and von misses stress; shear stress and total deformation were obtained from ANSYS software. The analysis on various geometric forms of connecting rod such as solid type, shell type has been carried out using modelling package such as SOLIDWORKS and ANSYS software. The apt result has obtained from the analysis, the deformation and stiffness of each material clearly shows in the output of the analyzed images and also in theoretical calculation. Comparing with the three materials the AA2014 possess less weight and better stiffness.

Experimental Study on Axial Pressure Stability Bearing Capacity of Transmission Tower Composite Rod of Circular Section

In order to further popularize the application of glass fiber reinforced resin matrix composite material in transmission tower, the axial compression bearing capacity test of two cross-section types of composite material rods, including solid round mandrel and hollow round pipe, was carried out, which provided data reserve for the standardization of calculation formula of axial compression bearing capacity of composite material rod. In this paper, the applicability and influence factors of Euler formula and yield criterion stability calculation method were analyzed, the test data were fitted, and the value of the key coefficient in the calculation formula of the axial pressure stability coefficient of composite material compression bar of circular section was proposed, which provided support for the standardization of the calculation method of the bearing capacity of composite material compression bar for transmission tower.

Boron chemistry during transportation in the high temperature region of a boiling water reactor under severe accident conditions

ABSTRACT Boron (B) chemistry during transportation at temperatures above 400 K was experimentally investigated to evaluate the transport behavior of control rod material B during a severe accident (SA) of a boiling water reactor while considering effects of B on cesium (Cs) and iodine (I) behavior. The heating test on B2O3 specimens was conducted at 1150 K in a steam atmosphere using the dedicated experimental apparatus named the TeRRa reproducing release and transportation of B in an SA. New findings on B chemistry in the high-temperature region emerged. A large amount of released B2O3 vapor was deposited above 1000 K by condensation on stainless steel (SS). The B deposits and/or vapors significantly reacted with SS above 1000 K, forming 2FeO · FeBO3 The experimental data indicate that a large amount of released B from a degraded BWR control blade in an SA remains in the high-temperature region like a Reactor Pressure Vessel (RPV). These results and thermodynamic considerations suggest the presence of B deposits in the high-temperature region decrease the amount of Cs vapors transported from an RPV. This is attributed to the possible formation of low volatile compounds like CsBO2 from the reaction of B deposits and Cs vapors.

Biomechanical Study of a Novel, Expandable, Non-Metallic and Radiolucent CF/PEEK Vertebral Body Replacement (VBR).

Vertebral body replacement is well-established to stabilize vertebral injuries due to trauma or cancer. Spinal implants are mainly manufactured by metallic alloys; which leads to artifacts in radiological diagnostics; as well as in radiotherapy. The purpose of this study was to evaluate the biomechanical data of a novel carbon fiber reinforced polyetheretherketone (CF/PEEK) vertebral body replacement (VBR). Six thoracolumbar specimens were tested in a six degrees of freedom spine tester. In all tested specimens CF/PEEK pedicle screws were used. Two different rods (CF/PEEK versus titanium) with/without cross connectors and two different VBRs (CF/PEEK prototype versus titanium) were tested. In lateral bending and flexion/extension; range of motion (ROM) was significantly reduced in all instrumented states. In axial rotation; the CF/PEEK combination (rods and VBR) resulted in the highest ROM; whereas titanium rods with titanium VBR resulted in the lowest ROM. Two cross connectors reduced ROM in axial rotation for all instrumentations independently of VBR or rod material. All instrumented states in all planes of motion showed a significantly reduced ROM. No significant differences were detected between the VBR materials in all planes of motion. Less rigid CF/PEEK rods in combination with the CF/PEEK VBR without cross connectors showed the smallest reduction in ROM. Independently of VBR and rod material; two cross connectors significantly reduced ROM in axial rotation. Compared to titanium rods; the use of CF/PEEK rods results in higher ROM. The stiffness of rod material has more influence on the ROM than the stiffness of VBR material.

P87. Strategies for prevention of pseudarthrosis in adult spinal deformity: cobalt chrome rod, 4-rod fixation, and oblique lumbar interbody fusion with sacropelvic fixation

BACKGROUND CONTEXT Restoration of the sagittal alignment in adult spinal deformity (ASD) can produce excellent radiological and clinical outcomes, but pseudarthrosis is one of the most common complications with an incidence of 0% to 29%. Various surgical options are reported for reducing the incidence of pseudarthrosis, but these methods are controversial and have limitations. PURPOSE The purpose of this study was to identify the methods for reducing the incidence of pseudarthrosis in the surgical treatment of ASD. STUDY DESIGN/SETTING Retrospective, consecutive case review. PATIENT SAMPLE A total of 186 consecutive patients with degenerative lumbar kyphosis (average age 70.8 years) who underwent a long-segment fixation with a minimum 2-year follow-up. OUTCOME MEASURES Description and analysis of X-ray changes. METHODS Subjects were classified into the pseudarthrosis group (n=39) and the non-pseudarthrosis group (n=147). For predicting the factors of pseudarthrosis, patient factors, radiologic parameters, and surgical factors which include rod materials (Titanium vs Cobalt Chrome), the use of 4-rod fixation and sacropelvic fixation, correction methods (pedicle subtraction osteotomy vs oblique lumbar interbody fusion), and the history of the previous spine surgery were analyzed. RESULTS The overall pseudarthrosis rate was 21% (39/186). No significant differences in the incidence of pseudarthrosis regarding patient factors and preoperative radiological parameters were found between the two groups (p >0.05). Significant differences were observed in the postoperative sagittal vertical axis and thoracic kyphosis angle (p CONCLUSIONS Applications of cobalt chrome rod, 4-rod fixation, or oblique lumbar interbody fusion procedure with sacropelvic fixation will be promising methods for reducing pseudarthrosis in surgically treated ASD. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.

Validation of the BERKUT fuel rod module against mixed nitride fuel experimental data

The BERKUT module of the EUCLID/V1 integrated computer code has been developed for the performance analysis of fuel rods with nitride or oxide fuels of fast reactors using the quasi two dimensional approach. As far as the uranium-plutonium mixed nitride is considered as one of the basic nuclear fuel materials for the projects of advanced reactor facilities with liquid metal cooled fast reactors developed in Russia, the BERKUT module validation has been carried out against the experimental data observed in the in-pile mixed nitride fuel performance studies. The results of validation obtained taking into account the uncertainties of the fuel rod fabrication data, material properties, and irradiation conditions indicate that the BERKUT module adequately describes the mixed nitride fuel rod behavior in fast reactors.

Impact of Electrocautery on Fatigue Life of Spinal Fusion Constructs-An In Vitro Biomechanical Study.

Instrumentation failure in the context of spine surgery is attributed to cyclic loading leading to formation of fatigue cracks, which later propagate and result in rod fracture. A biomechanical analysis of the potential impact of electrocautery on the fatigue life of spinal implants has not been previously performed. The aim of this study was to assess the fatigue life of titanium (Ti) and cobalt-chrome (CoCr) rod-screw constructs after being treated with electrocautery. Twelve spinal constructs with CoCr and Ti rods were examined. Specimens were divided into four groups by rod material (Ti and CoCr) and application of monopolar electrocautery on the rods’ surface (control-group and electrocautery-group). Electrocautery was applied on each rod at three locations, then constructs were cyclically tested. Outcome measures were load-to-failure, total number of cycles-to-failure, and location of rod failure. Ti-rods treated with electrocautery demonstrated a significantly decreased fatigue life compared to non-treated Ti-rods. Intergroup comparison of cycles-to-failure revealed a significant mean decrease of almost 9 × 105 cycles (p = 0.03). No CoCr-rods failed in this experiment. Electrocautery application on the surface of Ti-rods significantly reduces their fatigue life. Surgeons should exercise caution when using electrocautery in the vicinity of Ti-rods to mitigate the risk of rod failure.

Measurement of the Temperature of Dielectric Rods in Heat Treatment in Microwave Devices with Longitudinal Interaction

A method for the construction of microwave devices with longitudinal interaction is proposed. Devices of the present type create uniform cross-sectional distribution of temperature of rods made of polymer composite materials. Results from theoretical and experimental investigations of the cross-sectional distribution of the temperature of the material of the rod as well as the parameters of the microwave device are presented.

Subgrains, Texture Evolution, and Dynamic Abnormal Grain Growth in a Mo Rod Material

The roles of subgrains, texture, and surface energy during dynamic abnormal grain growth (DAGG) were examined in a commercial-purity Mo rod material. DAGG was observed in this material during tensile deformation at 2023 K (1750 °C). Cooling of specimens after tensile testing was sufficiently rapid to preserve both subgrain structures developed during deformation and several abnormal grains at early stages of growth. These and other microstructural features were characterized to evaluate how subgrains and boundary character influence the early stages of DAGG. Subgrains were observed in the deformed polycrystalline material but were generally absent in newly formed abnormal grains. This was identified as the cause of the sudden drop in flow stress observed at the initiation of DAGG. It is proposed that subgrain intersections with abnormal grain boundaries provide a driving pressure for DAGG. Subgrains within the deformed polycrystals were observed to locally change the boundary curvature at their intersections with abnormal grain boundaries, which likely encouraged growth of the abnormal grains into the deformed polycrystals. Abnormal grains produced by DAGG retained crystallographic orientations and boundary characters that closely resembled those of the polycrystalline material from which they grew. This suggests that neither differences in orientation nor boundary character were important to DAGG in this material.

Rheological damping of slender rods

Efficient and accurate modelling of mooring and cable systems for Floating Offshore Wind Turbines are a key factor in the coupled dynamic analysis for the realistic assessment of such floating structures. In order to improve the modelling of the mooring and cable systems, a new extension of the slender rod finite element model proposed by Garret with the inclusion of rheological damping is presented. The model takes into account the damping produced for the rod material in both the axial and the bending forces. Derivation of the axial and bending damping forces is presented and assessed in terms of the critical damping. The implementation of the model is presented and tested through three verification simulations and two validation examples, which show a good agreement when comparing with experimental results and prove the capacity and robustness of the model.

Comparison of ASTM F2129 and ASTM F746 for Evaluating Crevice Corrosion.

Crevice corrosion is one of the major mechanisms that drives implant failure in orthopedic devices that have modular interfaces. Despite the prevalence of crevice corrosion in modular interfaces, very little is known with regards to the susceptibility of different material combinations to participate in crevice corrosion. In this study, we compare two electrochemical methods, ASTM F2129, Standard Test Method for Conducting Cyclic Potentiodynamic Polarization Measurements to Determine the Corrosion Susceptibility of Small Implant Devices, and a modified version of ASTM F746, Standard Test Method for Pitting or Crevice Corrosion of Metallic Surgical Implant Materials, in their ability to induce crevice corrosion. Four commonly used metals, 316 stainless steel, commercially pure titanium (Ti grade 2), Ti-6Al-4V (Ti grade 5), and cobalt-chromium-molybdenum per ASTM F1537, Standard Specification for Wrought Cobalt-28Chromium-6Molybdenum Alloys for Surgical Implants (UNSR31537, UNSR31538, and UNSR31539), were used to form crevices with a rod and washer combination. As a control, the metal rod materials were tested alone in the absence of crevices using ASTM F2129 and the modified ASTM F746 method. As another control to determine if crevices formed with polymeric materials would influence crevice corrosion susceptibility, experiments were also conducted with metal rods and polytetrafluorethylene washers. Our results revealed more visible corrosion after ASTM F2129 than ASTM F746. Additionally, ASTM F746 was found to falsely identify crevice corrosion per the critical pitting potential when visual inspection found no evidence of crevice corrosion. Hence, ASTM F2129 was found to be more effective overall at evaluating crevice corrosion compared to ASTM F746.

Design optimization of a diesel engine connecting rod

Rotary motion is generated from a crankshaft’s piston alternating motion using a connecting rod. The engine combustion gases and components motion of inertia exert pressures that induces compressive and tensile stress in the connecting rod respectively [1], [2]. Connecting rods fail due to its overloading, bearing failure, irregular adjustments of the bolts and faulty assembly or fatigue [3]. It is important for connecting rods to be able to withstand the complex high tensile loads that acts on them. As a result, numerous design technology, material selection, working and fatigue test of a connecting rod have been studied and presented [4]. Mechanical properties (such as hardness, tensile strength, rigidity and fatigue resistivity) of the materials used in the manufacture of a connecting rod need vehicles depends on the design of the connecting rod. Failure of connecting rod is attributed to the in availability of much strength needed to hold the load. This can be overcome with the life cycle extended by increasing the strength [5].
 Finite element analysis of connecting rod have been conducted and presented by a lot of researchers. In [6], theoretical and FEA of an IC engine connecting rod was conducted. The result of the analysis obtained shows the causes of failure at the fillet of both ends due to the induced stress. In [7] static FEA for fatigue, deformation and weight optimization of a connecting rod using ANSYS workbench is carried out and presented. From the suggested design changes obtained from the weight optimization result, the failure result is further updated to achieve a better result. In a paper by Bansal, dynamic stress analysis was carried out on a single cylinder four stroke diesel engine connecting rod of Aluminum material using FEA. The optimization was also done under dynamic loading with the boundary conditions and inputs determined from the pressure-volume diagram and engine specification chart respectively are carried out with different meshing size for an accurate result. [8].
 FEA is the commonly employed computational tool for testing and modifying engineering structures within certain design limit. It involves diving in to small units known as ‘elements’ for static and dynamic analysis of simple to complex model under different design constraints. Further investigation can also be done to improve the design for optimal performance and lifespan with regards to design failure [9].
 Many kinds of literature have worked on weight optimization. Gaikwad in his paper modifies a roller conveyor by performing weight optimization after carrying out static analysis on the roller conveyor [10] In another paper by [10] the weight of a roller conveyor was reduced thereby saving the materials under specific load constraints using finite element method.
 In this paper shape optimization with target weight reduction rate of 20 to 60% with an interval of 10 under a static loading of 100N. Further analysis for structural optimization is also done to determine a new optimized structure with new deformation and stress values respectively. The analysis is carried out in ANSYS static structural, mechanical solver with a tensile force of 100N acting on its larger end.

Retrospective Multicenter Assessment of Rod Fracture After Anterior Column Realignment in Minimally Invasive Adult Spinal Deformity Correction

Anterior column realignment (ACR) was developed as a minimally invasive method for treating sagittal imbalance. However, rod fracture (RF) rates associated with ACR are not known. Our objective was to assess the rate of and risk factors for RF following ACR in deformity correction surgery. We conducted a retrospective multicenter review of patients with adult spinal deformity (ASD) who underwent ACR for deformity correction. ASD was defined as coronal Cobb angle ≥20°, pelvic incidence-lumbar lordosis >10°, sagittal vertical axis ≥5 cm, pelvic tilt ≥25°, or thoracic kyphosis ≥60°. Inclusion criteria were ASD, age >18 years, use of ACR, and development of RF or full radiographs obtained at least 1 year after surgery that did not demonstrate RF. Ninety patients were identified, with mean follow-up of 2.3 ± 1.4 years (age, 64.1 ± 9.4; 54 [60%] women). The most common ACR location was L3/4 (42 cases; 47%). Mean fusion length was 7.5 ± 3.6 levels. Four (4.4%) of 90 patients developed RF within 12 months of surgery. RF occurred adjacent to ACR in all cases; RF was not associated with focal correction (P= 0.49), rod material (P= 0.8), degree of correction (P > 0.07), or interbody at L5/S1 (P= 0.06). RF was associated with longer fusion constructs in univariate (P= 0.002) and multivariate (P=0.03) analyses. RF occurred in 4.4% of patients with ASD who underwent ACR with a minimum of 1-year follow-up. RF was not associated with focal correction but appears to be associated with global correction and extent of fixation.

USING OPTIMAL METHOD FOR CUTTING ROD MATERIALS

The article presents an optimal method to cut rod materials. By this method, the relative functions between the number of products cut from the given materials and conditions are first established. Then, the powerful computing capabilities of Mathematica software are applied to solve the problems. This method has a wide range of application and is convenient in use.

Analysis of the velocity relationship and deceleration of long-rod penetration

The relationship between the average penetration velocity, $$ \bar{U} $$ , and the initial impact velocity, $$ V_{ 0} $$ , in long-rod penetration has been studied recently. Experimental and simulation results all show a linear relationship between $$ \bar{U} $$ and $$ V_{ 0} $$ over a wide range of $$ V_{ 0} $$ for different combinations of rod and target materials. However, the physical essence has not been fully revealed. In this paper, the $$ \bar{U} - V_{ 0} $$ relationship is comprehensively analyzed using the hydrodynamic model and the Alekseevskii–Tate model. In particular, the explicit $$ \bar{U} - V_{ 0} $$ relationships are derived from approximate solutions of the Alekseevskii–Tate model. In addition, the deceleration in long-rod penetration is discussed. The deceleration degree is quantified by a deceleration index, $$ \alpha = {{2\bar{\mu }} \mathord{\left/ {\vphantom {{2\bar{\mu }} {(K\varPhi_{Jp} )}}} \right. \kern-0pt} {(K\varPhi_{Jp} )}} \approx Y_{p} \rho_{p}^{{{{ - 1} \mathord{\left/ {\vphantom {{ - 1} 2}} \right. \kern-0pt} 2}}} \left( {\rho_{p}^{{{{ - 1} \mathord{\left/ {\vphantom {{ - 1} 2}} \right. \kern-0pt} 2}}} + \rho_{t}^{{{{ - 1} \mathord{\left/ {\vphantom {{ - 1} 2}} \right. \kern-0pt} 2}}} } \right)V_{0}^{ - 2} , $$ which is mainly related to the impact velocity, rod strength, and rod/target densities. Thus, the state of the penetration process can be identified and designed in experiments.

Control rod material effect on safety parameters of research reactors

Abstract Control rods provide adjustable manipulation of reactivity and prevent fission reaction from accelerating beyond control. In this paper, the Monte Carlo Code, MCNP6 was used to study the effect of using various control rod materials on the main safety parameters of a typical plate type material test research reactor. Three types of control rod materials were considered, Ag-In-Cd, B4C, and Hafnium. Parameters investigated are reactivity worth, excess reactivity and shutdown margin of absorber materials. The model was used to evaluate the effect of various materials on the flux and power shaping of the core. The resulting multiplication factor for this study was compared with previous work and found acceptable. It was found that boron carbide has the largest effect on safety parameters, as well as flux and power distribution.

Development of a dual magnetostrictive material rods–based electro-hydrostatic actuator

Recently, the use of smart material–based electro-hydrostatic actuators is increasingly becoming more attractive to overcome the inherent disadvantages of conventional actuation systems and to offer new opportunities for performance improvement. A new type of a dual magnetostrictive material rods–based electro-hydrostatic actuator is presented in the current study. An active rotary rectification valve is utilized to convert small, high-frequency vibration displacements of the magnetostrictive material rods into continuous, smooth and bidirectional motion of a hydraulic cylinder by fluid rectification. Simulation and experiments were performed to confirm the feasibility of the new concept. The experimental results indicate that the dual magnetostrictive material rods–based electro-hydrostatic actuator exhibits a maximum flow rate that is approximately twice that of a single magnetostrictive material rod–based electro-hydrostatic actuator, and that the operating frequency increases from 110 to 150 Hz.

Effect of Scour on the Natural Frequency Responses of Bridge Piers: Development of a Scour Depth Sensor

Local scour is the removal of soil around bridge foundations under the erosive action of flowing water. This hydraulic risk has raised awareness of the need for developing continuous monitoring techniques to estimate scour depth around bridge piers and abutments. One of the emerging techniques is based on monitoring the vibration frequency of either bridge piers or a driven sensor in the riverbed. The sensor proposed in this study falls into the second category. Some unresolved issues are investigated: the effect of the geometry and material of the sensor, the effect of the embedded length and the effect of soil type. To this end, extensive laboratory tests are performed using rods of different materials, with various geometries and lengths. These tests are conducted in both dry sand and a soft clayey soil. Since the sensor will be placed in the riverbed, it is crucial to evaluate the effect of immersed conditions on its response. A numerical 3D finite-element model was developed and compared against experimental data. This model was then used to compute the ‘wet’ frequencies of the sensor. Finally, based on both the experimental and numerical results, an equivalent cantilever model is proposed to correlate the variation of the frequency of the sensor to the scour depth.