Pin Diameter Research Articles

Technical analysis and performance test of chopper machines for composting rice straw

Nutrients diminishing become one of the low productivity of rice. Treatment of straw burned and the ashes as fertilizer remove nutrients contained therein. Composted rice straw so that the soil nutrient enhanced by the provision of rice straw compost continuously. Rice straw compost necessary optimal cutting rice straw with a length of 5 cm to 10 cm to accelerate the composting process. Paddy straw chopper is able to produce the chopped length, but the lack of data and the technical feasibility test engine performance so that the necessary research. The experiment was conducted in March-May 2016 in Bumiwangi Village, Ciparay, Bandung West Java and Agriculture Equipment dan Machine Laboratory Faculty of Agriculture Industrial Technology University of Padjadjaran. The method used descriptive analysis, namely making measurements, observations, calculations, and analyses so that the data obtained eligibility machine. Results of analysis techniques, namely the need for locomotion 1.83 HP, unit transmission with 4 belts, shaft diameter 23 mm, the diameter of the pin cylinder enumerator 7.58 and pin diameter motor of 7.40 mm, the size of the spi (9 × 9 × 27) mm, bearing life 6,740.64 h, the deflection order of 1.3 × 10−3 mm and the weld strength 44,660 N and 57,417.07 N meets the technical feasibility than the number of belts. The results of the performance test, the density 128.78 kg/m3, the theoretical capacity 336.20 kg/h, the actual capacity of 304.680 kg/h, the enumeration efficiency of 90.62%, the fuel consumption of 3.19 liters/h, the theoretical power consumption 41.91 HP, enumeration yield 88.302%, the percentage of chopped chunks of 46%, the noise 97.5 dB and vibration of 21.6 mm/s as a whole meets the performance specifications except the cut length, noise and vibration

Energy absorption capability of composite bolted joints undergoing extended bearing failure

Innovative crashworthiness strategies are needed for future narrow-body composite fuselage aircraft due to limited crash energy absorption capability below the cargo floor. A recently-proposed approach is to use specially-designed “tension absorber” joints which absorb energy through an extended bearing failure process. To explore the design space, experimental tests are performed on pin-loaded joints in a widely-used carbon fibre/epoxy composite, with varying stacking sequence, pin diameter and laminate thickness. A bespoke rig is used to pull the pin completely through the laminate. Performance parameters include ultimate bearing strength, mean crushing stress and mass-specific energy absorption. Three-dimensional computed tomography (3D CT) and scanning electron microscopy are used to examine failure and damage. Diameter-to-thickness ratio is found to be an excellent predictor of energy absorption, with small values giving best results, provided the thickness is sufficient to avoid global bending of the specimen. The use of a well-characterised material and availability of 3D CT data enables the results to be used for validation of analysis tools.

Strength enhancement of bonded composite laminate joints reinforced by composite Pins

This paper presents an experimental and numerical investigation in the static strength enhancement of composite laminate Single Lap bonded Joints (SLJ), reinforced by pins made of Uni-Directional (UD) fibre reinforced plastic composite materials. Bonded lap joint specimens were experimentally tested in tension to obtain the failure loads and failure modes. The specimens were subsequently benchmarked against the hybrid version of the joint resulted from the introduction of composite Pins. The Pin reinforcement enhanced the hybrid single lap joint strength by an average of 19.1% increase. Numerical models generated were used for correlation with the experimental results. Numerical and experimental results observation indicated that increased strength of the hybrid bonded/Pinned joint was partly attributed to the load sharing between the adhesive and the Pin past the adhesive failure initiation as well as to the enhanced out-of-plane bending stiffness after the Pin introduction on the lap joint. Numerical investigations were performed as well with hybrid SLJ reinforced by composite pins versus designs employing metallic Pins. The simulations showed that for the investigated lap joint design parameters, the hybrid metallic pin joint failed at a higher failure load. Nevertheless, the hybrid joint utilizing the composite Pin could benefit from the enhanced corrosion resistance properties. In the case of applying a larger composite Pin diameter and/or rearranging the fibre orientation in the Pin, the hybrid SLJs could potentially achieve higher strength characteristics before the adhesive bond ultimate failure in relation to the steel Pin, as well as resulting to additional weight saving up to 46.9%.

Mechanical behavior of friction stir welded high-density polyethylene sheets

In the present work, sheets of high-density polyethylene, reinforced with strips of polypropylene using a friction stir welding technique were executed. Welding was carried out using a friction stir welding tool of 20 mm shoulder diameter and 5 mm for both pin diameter and pin length with zero tilt angle, the percentages of polypropylene added to the welding zone were 15, 20, 25, 30% (as a percentage of the added polypropylene to the welding zone), the recommended high tool rotation speed and low tool travel speed (520 rpm, 20 mm/min, respectively) were applied in all tests, the plunge depth was 0.5 mm (the penetration depth of tool shoulder from workpiece surface), dwell time at the event of submerging the pin into the faying surfaces and before initiating the tool travel speed was 45 seconds. Mechanical tests, represented by flexural and impact tests, exhibited an improvement in the mechanical properties of the welded specimens for the case of 25% added polypropylene. Friction stir welding has extraordinary potential to create imperfection-free joints and to initiate a high-quality weldment of high-density polyethylene sheets reinforced by polypropylene strips.

Barkhausen noise analysis of friction stir processed steel plate

This work investigates the variation in material properties of steel upon friction stir processing through its magneticresponse. The steel plate of grade IS 2062 having a thickness of 3 mm have been friction stir processed (FSPed) using a toolof tungsten carbide with a 15 mm shoulder diameter along with 3 mm pin diameter with traverse of 150 mm/minute and a800 RPM revolving speed. Magnetic response of these processed plate and base metal has been recorded using Barkhausennoise (BN) analyzer in terms of BN signal parameters i.e. the rms value and pulse count or number of pulses. Barkhausennoise analysis results have been validated with micro-hardness testing and metallographic study of as received metal and theprocessed samples. Higher microhardness has been found in processed sample in comparison to the as received metal due tograin refinement owing to the combined effect of plastic flow of material during stirring action of the rotating tool and thefrictional heat. Barkhausen noise analysis has been performed in a wide range of magnetic field intensity (MFI) andexcitation frequencies to study their effect on variation in rms value and the number of pulses.

Determining the tribological properties of different 3D printing filaments

The paper aims to determine the friction coefficient and wear behaviour of different 3D filaments in contact with a metallic disc. The method used for testing was the pin-on-disc method, where 3D half inch diameter pins with a half sphere end were printed out of the different filaments and rotated on the disc. The optimal time for measuring the friction coefficient was determined by observing when a sudden change in friction was recorded by the sensor as a result of material deposition on the disc. All filaments were tested for the same amount of time using the same normal loads. The friction behaviour was monitored and the mass wear was determined by weighting the spheres before and after each test. The research work of this paper was orientated to determine which 3D printing filament is most suitable for building different parts that come in contact with one another such as parts for creating an innovative 3D printed smart shoes sole.

In vivo evaluation of bending strengths and degradation rates of different magnesium pin designs for oral stapler.

Magnesium alloys have been potential biodegradable implants in the areas of bone, cardiovascular system, gastrointestinal tract, and so on. The purpose of this study is to evaluate Mg-2Zn alloy degradation as a potential suture material. The study included Sprague-Dawley (SD) rats in vivo. In 24 male SD rats, tests in the leg muscle were conducted using traditional surgical incision and insertion of magnesium alloys of different designs into the tissue. The material degradation topography, elemental composition, and strength of the pins were analyzed. This paper explores magnesium pins with different cross-sectional shapes and diameters to establish a suitable pin diameter and shape for use as an oral stapler, which must have a good balance of degradation rate and strength. The results showed there were good bending strengths over different degradation periods in groups with diameters of 0.8 mm and 0.5 mm, and no significantly different bending strength between the groups of triangle and round cross-section shapes with same diameter of 0.3 mm, although the degradation rate still needs to be improved.

Forming of pin on thick plate by open extrusion

A special-shaped part that is a small pin formed on a plate has been required to fit a plastic pulley into the pin for a lightweight construction. This formed part is stronger and more reliable than a small pin bonded with a plate. In this study, a process of open extrusion to form the pin on the plate and the forming conditions are proposed. Conventional extrusion indicates a critical overload to form a small pin by FEM analysis when the billet is constrained with a container. Open extrusion using no container enables to form a longer pin with 1.6 = l / d under a low forming load, where d of the pin diameter is 3.0 mm and l of the pin length is 4.7 mm on a copper plate with a thickness of 2.3 mm.

Influence of Refill Friction Stir Spot Welding Technique on the Mechanical Properties and Microstructure of Aluminum AA5052 and AA6061-T3

This paper presents the effects of using the refill friction stir spot welding (RFSSW) technique on the mechanical properties and microstructure of aluminum AA5052 and AA6061-T3. Specimens were first prepared from AA5052 sheet of thickness 2 mm and AA6061-T3 of 1.6 mm, for chemical analysis and mechanical tests. Workpieces were then stir spot welded by RFSSW at four rotational speeds (2000, 2500, 3000 and 4000 rpm) using two tool pin diameters (5 and 7 mm) to carry out the tensile shear tests. Microhardness testing was conducted at the best conditions along the cross-section of the welded specimens, as well as microstructure examination. The results of the tensile shear tests manifested that, for AA5052 and AA6061-T3 at the tool rotational speeds 2000 rpm and 3000 rpm, respectively, using a tool pin of 7 mm the ultimate tensile shear force was slightly higher than at other speeds in both diameters of tool pin (5 and 7 mm). However, the microhardness results displayed a W-shape at the best conditions. Finally, the microstructure inspection revealed the morphology of the major zones of the weld joint.

Treatment of Selected Distal Radius Fractures with Nonbridging External Fixation.

A nonbridging external fixation (NBX) system with 1.6-mm diameter pins provided excellent stability for distal radius fractures in cadavers. For the present study, all patients with distal radius fractures were seen by the surgeon authors. Fractures that were displaced and unstable, including Orthopaedic Trauma Association (OTA) types 23-A2.3 to C3.3, were reduced and fixed with the NBX system. The Western Institutional Review Board granted approval (296864) for this retrospective study. Fractures numbered five OTA-A2, eight OTA-A3, two OTA-B3, one OTA-C1, two OTA-C2, and eight OTA-C3. In total, the study included 26 patients. At fixator removal, average dorsiflexion was 37.0° ± 17.8°; volar flexion, 39.4° ± 17.2°; pronation, 80.6° ± 16.1°; and supination, 48.1° ± 24.2°. Follow-up averaged 11.7 mo ± 19.2 mo. At final follow-up, average dorsiflexion was 52.9° ± 25.0°; volar flexion, 53.1° ± 23.7°; pronation, 80.8° ± 14.5°; and supination, 67.7° ± 30.3°. Average radial tilt at the time of injury was 11.6° ± 8.3°; post op to 23.9° ± 5.0°; and at last follow-up, 23.1° ± 5.0°. Average radial styloid length at the time of injury was 4.1 mm ± 3.7 mm; post op to 11.4 mm ± 3.0 mm; and at last follow-up, 10.5 mm ± 3.1 mm. Volar tilt at the time of injury averaged -19.6° ± 14.8°; reduced to 9.8° ± 6.3°; and at last follow-up, 7.5° ± 6.5°. This form of nonbridging fixation is safe and effective at maintaining reduced, extra- and intra-articular, distal radius fractures and allows functional range of motion with minimal complications.

ВПЛИВ КОНСТРУКТИВНИХ РІШЕНЬ КОМПОНУВАННЯ ТА ПОХИБОК ВИГОТОВЛЕННЯ ЕЛЕМЕНТІВ ШИРОКОСМУГОВОЇ РУПОРНОЇ АНТЕНИ НА ЇЇ ТЕХНІЧНІ ХАРАКТЕРИСТИКИ

The results of the research of the main releases of arrangement of horn antenna with two ridges, which differ in the ways of fixing the elements: bolt connection (rivets) and soldering (welding), are presented in the article. The influence of inaccuracies in the manufacture of particular antenna elements (errors in the geometric dimensions of the waveguide and the horn aperture, errors in the location of the feed pin, differences in the relative permittivity of the insulating material from the calculated one and others) and their interconnections (the width of the slots between the horn aperture plates, the distance between the ridges at the feeding point) on the main antenna characteristics (voltage standing-wave ratio, gain, radiation pattern). The researches were carried out using software environments for computer-aided designing, modeling and optimizing three-dimensional electromagnetic systems ANTENNA MAGUS and CST STUDIO SUITE. It has been found that with the same accuracy of manufacturing the constituent elements of a wideband horn antenna, the considered releases of arrangement provide similar technical characteristics. The research of manufacturing errors of the antenna elements and their interconnections showed that the longitudinal waveguide dimensions, the distance between the ridges at the point of excitation, the location and diameter of the feed pin, and also the dielectric characteristics of the insulating material have the greatest influence on the characteristics of the antenna. It has been established that a change in particular antenna sizes by 10% can lead to a significant deterioration in its matching. The system of tolerances for the sizes and connections of antenna elements, the adherence of which will ensure the conformity of the characteristics of the manufactured example to those obtained in the process of modeling and optimization using specialized software, is justified.

Basic design parameter optimization on water cooled thorium breeder reactor

Basic study on optimization of heavy water cooled thorium breeding reactor has been investigated to estimate the feasible design region of breeding and negative void reactivity coefficient. Those parametric surveys are moderator to fuel ratio, fuel pin diameter, fuel pellet power density, and void faction. A fuel pin diameter of 14.5 mm shows the optimum feasible fuel breeding and less required U-233 fissile content. The systems require the enrichment less than 8% and it gives some possible area of breeding. The effect of moderator is essential to make the negative void reactivity. Void fraction effect is still good enough to make more negative void reactivity, however, for no more heavy water as moderator, it obtains less negative void reactivity or becomes slightly positive. It has been shown that several significant parameters affect to the feasibility breeding windows and potential negative void reactivity based on heavy water-cooled thorium reactor.

Finite Element Analysis of Six Transcortical Pin Parameters and Their Effect on Bone-Pin Interface Stresses in the Equine Third Metacarpal Bone.

The objectives of this study were to validate a finite element model of the equine distal limb transfixation cast and to determine the effect of six transcortical pin parameters on bone-pin interface (BPI) stresses in the third metacarpal bone. A transfixation cast finite element model was developed from a computed tomography scan of the third metacarpal bone and modelled pin elements. The model was validated by comparing strain measured around a 6.3-mm transfixation pin in the third metacarpal bone with the finite element model. The pin parameters of diameter, number, location, spacing, orientation and material were evaluated by comparing a variety of pin configurations within the model. Pin diameter and number had the greatest impact on BPI stress. Increasing the diameter and number of pins resulted in lower BPI stresses. Diaphyseal pin location and stainless-steel pins had lower BPI stresses than metaphyseal location and titanium alloy pins, respectively. Offset pin orientation and pin spacing had minimal impact on BPI stresses during axial loading. The results provide evidence that diameter and number are the main pin parameters affecting BPI stress in an equine distal limb transfixation cast. Configurations of various pin size and number may be proposed to reduce BPI stresses and minimize the risk of pin related complications. Further refinement of these models will be required to optimize pin configurations to account for pin hole size and its impact on overall bone strength.

Parametric optimization for friction stir welding with AA2024 and AA6061 aluminium alloys by ANOVA and GRG

Aluminium alloy AA2024 and AA6061 welding and its combinations have been consistently represented a respectable challenge for creators and expertise. The alloys 2024 and 6061 composites, especially heat-readable materials, are hard to bond by combination affixing systems. The different combination of welding, for example, AA2024 and AA6061 Alloy is a significant issue during FSW. In this article, the impact of Rotation speed; Travel Speed; and Different Diameter of Tool Pins of 2024 and 6061 alloy through FSW was examined by GRA (Grey Relational Analysis). The ANOVA was utilized to try out the preeminent significant travel speed of welding and speed of tool rotation influencing the responses. The essential and collaboration effect of data features on the ordinary responses are analyzed. The normal qualities and estimated qualities are truly close.

Experimental determination of buoyancy induced convection heat transfer characteristics in a rectangular cavity with cylindrical porous medium fixed between pin fins

The present work aims to investigate the heat transfer characteristics of heated cylindrical pins within an air-filled rectangular enclosure experimentally in a natural convection dominated regime. The experiments are performed to analyze the effects of fin spacing (25 mm ≤ S ≤ 100 mm) and Rayleigh number (248,659 ≤ Ra ≤ 578,395) as key factors at constant pin height (l = 25 mm) and pin diameter (d = 10 mm) values. The results confirm the existence of optimum fin spacing providing maximum heat transfer enhancement. The investigation is extended further to quantify the effects of the presence of cylindrical porous pins with the uniform diameter (dp = 15 mm), pin length (lp = 20 mm) and calculated porosity of 19.3% by volume on the thermal performance of the system. The results reveal the improved system performance due to the presence of a porous medium for all tested system configurations. Some new empirical correlations predicting system performance are also proposed those demonstrate the satisfactory qualitative behavior of system performance.

Influence of tool rotational speed on the mechanical and microstructural properties of AISI 316 Austenitic stainless steel friction stir welded joints

Fabrication of steel joints using fusion welding technique will result in defects like hot cracking, and heavy residual stresses along with coarse microstructural features in the weldments. To overcome these problems, friction stir welding (FSW) technique was employed to fabricate steel joints. Tungsten based alloy tool is used in this investigation to withstand high dynamic frictional forces at elevated temperature generated during welding. Tool shoulder diameter of 25 mm, pin diameter of 3 mm and pin length 2.9 mm was employed to carry out the friction stir welding on SS316 steel plate of 3 mm. Sound joints produced at a constant welding speed of 40 mm min−1, axial load of 15 kN at different tool rotational speed of 600 rpm and 700 rpm. In accordance with ASTM standards, Tensile, Compression, Micro hardness and impact tests were carried out to assess the mechanical properties of weld joints and the base metal. Mechanical testing results showed that tensile and hardness of the welded material was improved in compared with base metal. However, the impact strength of the welded metal is reduced. Furthermore, the base metal and welded metal were subjected to study microstructural analysis using optical and scanning electron microscopy. EDS and XRD analysis were also carried out on welded zone to understand about the formation of new phases in weld zone and it is surroundings.

The long-term outcomes of modified Harrington procedure using antegrade pins for periacetabular metastasis and haematological diseases.

The aim of this study was to present the long-term surgical outcomes, complications, implant survival, and causes of implant failure in patients treated with the modified Harrington procedure using antegrade large diameter pins. A cohort of 50 consecutive patients who underwent the modified Harrington procedure for periacetabular metastasis or haematological malignancy between January 1996 and April 2018 were studied. The median follow-up time for all survivors was 3.2 years (interquartile range 0.9 to 7.6 years). The five-year overall survival rate was 33% for all the patients. However, implant survival rates were 100% and 46% at five and ten years, respectively. Eight patients survived beyond five years. There was no immediate perioperative mortality or complications. A total of 15 late complications occurred in 11 patients (22%). Five patients (10%) required further surgery to treat complications. The most frequent complication was pin breakage without evidence of acetabular loosening (6%). Two patients (4%) underwent revision for aseptic loosening at 6.5 and 8.9 years after surgery. Ambulatory status and pain level were improved in 83% and 89%, respectively. The modified Harrington procedure for acetabular destruction has low complication rates, good functional outcome, and improved pain relief in selected patients Cite this article: Bone Joint J 2019;101-B:1557-1562.

Effect of pin inclination angle on flow and heat transfer characteristics for a row of pins in a flow channel

The aim of this research was to study flow and heat transfer characteristics with a row of inclined pins in a rectangular channel. The cylindrical pins of diameter D = 10 mm were mounted on the heat transfer surface in spanwise direction of the channel. The pin-to-pin distance was fixed at S = 2D. Two of pin heights H were studied, namely short pins or long pins with H = 2D or H = 3.2D, respectively. The effects of pin inclination angle were investigated for θ=30o, 45o, 60o, 90o, 120o, 135o, and 150o in the range of Reynolds number from 14,000 to 32,860. The local temperature on endwall surface was measured using a thermochromic liquid crystal sheet coupled with image processing. Numerical simulations were used to obtain three-dimensional flow fields and heat transfer rates on pin surfaces and endwall surface. Results for the case H/D = 2 show that pins inclined by θ=30o, 45o and 60o can enhance heat transfer downstream of the pin row, from the baseline case of pins with θ=90o. The heat transfer was improved by a pair of counter-rotating vortices near the heat transfer surface. These vortices induced the main flow to attach on the heat transfer surface. The pin inclinations θ=120o and 135o somewhat improved heat transfer behind the pins. However, the inclination θ=150o gave the lowest heat transfer rate on the endwall surface. The heat transfer on endwall surface with H/D = 3.2 was poorer than with H/D = 2 because the counter-rotating vortices did not reach the heat transfer surface. The inclination θ=30o with H/D = 2 gave the best thermal performance. The local Nusselt number on the rear side of pin surfaces with H/D = 3.2 and inclinations θ=30o, 120o, 135o and 150o tended to increase from the case H/D = 2, due to a jet-like flow attachment on the pin surfaces. However, the local Nusselt number on pin surfaces with H/D = 3.2 and inclinations θ=45o and 60o tended to be lesser than with H/D = 2, due flow separation downstream far from the pins.

A two-stage retrospective analysis to determine the effect of entry point on higher exit of proximal pins in lateral pinning of supracondylar humerus fracture in children

BackgroundKirschner wire fixation remains to be the mainstream treatment modality in unstable or displaced supracondylar humerus fracture in children, with divergent lateral pins being the most preferred due to their sufficient stability and decreased risk of ulnar nerve injury. However, the entry point at which the proximal lateral pin can be inserted to achieve a more proximal exit and maximum divergence has not been reported. This study retrospectively analyzed the characteristics and factors influencing the entry and exit points of the proximal lateral pins.MethodsThe study was divided into two stages. In stage one, the entry and exit points of the proximal pins of lateral pinning configuration were analyzed from intra-operative radiographs of children treated for extension-type supracondylar humerus fractures. The coronal and sagittal pin angles formed by the proximal pins were also measured. Using the findings of stage one, we intentionally tried to achieve a more proximal exit with the proximal pins in stage two. Comparisons between groups of patients treated by random and intentional pinnings were done statistically.ResultsIn the first stage, 47 (29.2%) of the 161 proximal pins exited above the metaphyseal-diaphyseal junction (MDJ) region. Of these, 85.1% entered from lateral and posterior to the ossific nucleus of the capitellum (ONC). The pin angles averaged 58.4° and 90.5° in the coronal and sagittal planes respectively. In the second stage, 47 (65.3%) proximal pins in the intended group exited above the MDJ region, while only 32 (36%) in the random group exited above the MDJ region.ConclusionWhile aiming at the upper border of the distal MDJ during pinning, lateral pins can easily achieve a higher, proximal exit above the MDJ if inserted from lateral and posterior to the ONC and parallel to the humeral shaft in the sagittal plane. Higher exit can also be easily achieved in younger patients and patients fixated with smaller diameter pins.

A transient study on two phase adiabatic flow over micro circular pin heat sinks

In the present work, a transient numerical study on two-phase flow over circular staggered and inline micro pin fins is conducted. Pin diameter, fluid density ratio, and surface tension have been taken into account. Diameters of micro pins are in the range of 50 to 250μm; moreover, a variation of 100 fold in the surface tension and density ratio are considered. In order to solve the numerical model of a micro heat sink, a volume of fluid (VOF) method using open package Gerris Flow Solver (GFS) is employed. Pressure drop, flow velocity, as well as void fraction for all cases are presented and discussed. Based on the results, transient nature of flow is observed even after the first transition phase. Flow mixing as an essential phenomenon in heat transfer is thoroughly discussed. Our study proves that with an increase of pin diameter the flow mixing near micropins is hindered. Moreover, bridge formation in staggered conformation was observed which may reduce the heat transfer. Additionally higher surfaces tension ratio yielded a better flow mixing.