Outer Shaft Research Articles

A new periodic shaft model for broadband ultra-low-frequency vibration reduction in spinning shafts

Vibration isolation is found in periodic structures having a special feature known as vibration band gap. A periodic shaft model is proposed and analyzed in this study. This model is composed of a spinning solid shaft carrying periodic arrays of outer cantilever hollow shafts. The generalized differential quadrature rule (GDQR) method combined with the Bloch theorem is used to calculate the vibration band gaps of this periodic shaft. Results are verified by the forced vibration responses obtained using the GDQR method. Results indicate that for each length of the hollow shafts, there is a spinning velocity range for which the first band gap starts from zero frequency. In other words, each model of this periodic shaft can be used for vibration reduction over an ultra-low-frequency band gap at different spinning velocities. Results also indicate that there is a model with specific value of the hollow shafts length for which the second band gap is very close to the first band. For this model, the width of the ultra-low-frequency band gap is much greater than other models. Finally, verification of the GDQR method shows that it can be used as a precise numerical method for free and forced vibration analysis of the spinning shafts.

Performance testing of a novel angle comparator with inner and outer shafts

Performance testing of a novel angle comparator with inner and outer shafts

Peroneal artery injury potential due to different syndesmosis screw placement options: a simulation study with lower extremity computed tomography angiography.

The aim of this study is to assess the risk of peroneal artery injury of hardware placement at the fixation of syndesmotic injuries. The lower extremity computed tomography angiography was used to design the study. The syndesmosis screw placement range was simulated every 0.5cm, from 0.5 to 5cm proximal to the ankle joint. The screw axes were drawn as 20°, 30° or individual angle according to the femoral epicondylar axis. The proximity between the screw axis and the peroneal artery was measured in millimeters. Potential peroneal artery injury was noted if the distance between the peroneal artery to the axis of the simulated screw was within the outer shaft radius of the simulated screw. The Pearson chi-square test was used and a p-value < 0.05 was considered significant. The potential for injury to the peroneal artery increased as the syndesmosis screw level rose proximally from the ankle joint level or as the diameter of the syndesmosis screw increasds. In terms of syndesmosis screw trajection, the lowest risk of injury was observed with the syndesmosis screw angle of 20°. Simulations with a screw diameter of 3.5mm exhibited the least potential for peroneal artery injury. Thanks to this radiological anatomy simulation study, we believe that we have increased the awareness of the peroneal artery potential in syndesmosis screw application. Each syndesmosis screw placement option may have different potential for injury to the peroneal artery. To decrease the peroneal artery injury potential, we recommend the followings. If individual syndesmosis screw angle trajection can be measured, place the screw 1.5cm proximal to the ankle joint using a 3.5mm screw shaft. If not, fix it with 30° trajection regardless of the screw diameter at the same level. If the most important issue is the peroneal artery circulation, use the screw level up to 1cm proximal to the ankle joint regardless of the screw angle trajection and screw diameter.

Single-use flexible ureteroscopes: practice patterns, attitudes, and preferences for next-generation concepts.

Single use flexible ureteroscopes (su-fURS) have emerged as an alternative to reusable flexible ureteroscopes (r-fURS) for the management of upper urinary tract calculi. However, little is known about urologist usage and attitudes about this technology. Through a worldwide survey of endourologists, we assessed practice patterns and preferences for su-fURS. An online questionnaire was sent to Endourology Society members in January 2021. The survey explored current su-fURS practice patterns, reasons for/against adoption, and preferences for next generation models including developments in imaging, intra-renal pressure, heat generation, and suction. Responses were collected through QualtricsXM over a 1-month period from surgeons in North America, Latin America, Europe, Asia, Africa, and Oceania. The study was conducted according to the Checklist for Reporting Results of Internet E-Surveys (CHERRIES). 208 (13.9%) members responded to the survey. Most respondents (53.8%) performed >100 ureteroscopies per year. 77.9% of all respondents used su-fURS for less than half of all procedures while only 2.4% used su-fURS for every procedure. 26.0% had never used a su-fURS. Overall, usage was not influenced by a surgeon's geographic region, practice environment, or years of experience. Top reasons for not adopting su-fURS were cost (59.1%) and environmental impact (12.5%). The most desired improvements in design were smaller outer shaft size (19.4%), improved optics and vision (15.9%), and wireless connectivity (13.6%). For next generation concepts, the functions most commonly described as essential or important by respondents was the ability to suction fragments (94.3%) while the function most commonly noted as not important or unnecessary was incorporation of a temperature sensor (40.4%). su-fURS are not commonly used, even among urologists who perform a high number of fURS. The primary concern for adoption is cost and environmental impact. Suction capability was considered the most important future development.

The burden of cardiovascular disease in South Asia: the need for effective treatment

Dear Ma'am, Cardiovascular disease (CVD) is rapidly becoming the leading cause of death worldwide (1). According to global health projections, it will remain the number one cause of death in 2030. The Asian region has been shown to have a higher cardiovascular disease burden than Western countries, and most of this burden is borne by economically disadvantaged people mainly located in South Asian regions such as Pakistan. (1). A large-scale survey conducted in 53 cities in Punjab, Pakistan, found that 17.5% of the population suffered from cardiovascular disease (2). Mechanical thrombectomy is a minimally-invasive procedure where a specialized interventional radiologist utilizes specific equipment to remove a blood clot from an artery in a patient's body. This procedure treats arterial blockages caused by blood clots such as Deep Vein Thrombosis (DVT), Ischemic Stroke, etc (3). MegaVac, a part of mechanical thrombectomy, is the newest technique for the removal of blood clots from arteries. It is an invasive procedure that ensures the complete removal of clots from the occluded artery. The biggest advantage of this technique over typical clot removal is that it prevents embolus formation, which can occlude smaller arteries. The MegaVac Thrombectomy System is an intravascular mechanical thrombectomy and aspiration device with a single use that includes a thrombowire with an embolectomy component. A distal silicone-coated nitinol braid used in the SafeSealTM technology of the MegaVac Catheter swells to momentarily obstruct antegrade blood flow. The braid is expanded by the inner and outer coaxial shafts of the catheter body, briefly occluding the channel and enabling aspiration. SafeSeal funnel is activated by the assembly of the proximal handle. A nitinol embolectomy component that is part of the thrombowire can be used to draw material in the direction of the MegaVac catheter when it is inflated by the proximal actuation handle (4). Thrombectomy is a common and effective procedure for clot removal but in Pakistan thrombectomy is not as common compared to developed countries, primarily due to two reasons. First, Mechanical thrombectomy is exclusively available in four hospitals nationwide, with only one public hospital in Lahore providing this procedure (5). Second, it is an expensive procedure that ranges from 1700$ to 5000$ depending on the severity of the patient and the complexity of the procedure. Health Departments of Pakistan should provide this facility in more public hospitals so it becomes accessible to more people.

Abstract 054: Transradial Thrombectomy Using "Sheathless PV" Guide Catheter in Armenia: Three‐Year Institutional Experience in 103 Cases

Introduction Transradial access (TRA) in neuroendovascular procedures has gained popularity in recent years (1). It offers numerous advantages and stimulated development of long flexible large lumen guiding catheters as well as adoption of existing cost‐efficient alternatives used in cardiac and peripheral interventions (2,3). We report our three‐year experience using the Sheathless PV guide catheter (Asahi Intecc, Japan) in a consecutive series of acute stroke patients undergoing endovascular thrombectomy (ET) at a Comprehensive Stroke Center in Yerevan, Armenia. The interest in its use specifically for TRA stemmed from competitive price (∼ $100 per catheter vs ), hydrophilic coating of the outer shaft, as well as lack of femoral closure devices in the country. Methods We retrospectively identified all consecutive acute stroke patients who had undergone ET via TRA from a prospectively maintained institutional stroke database between June 2020 and June 2023. Data were collected on determinants of decision to proceed with TRA‐first approach, baseline patient imaging and clinical characteristics, location of the occlusion, puncture‐to‐reperfusion time (PT‐RT), conversion to transfemoral access (TFA), periprocedural complications, and procedural/clinical outcomes. Results were compared to patients who underwent TFA‐first ET over the same time period. The Mann‐Whitney U‐test was used to analyze the continuous variables and chi‐square test was used for categorical variables. Standardized TRA technique involved exchanging the puncture needle to a short 6Fr introducer first, then over a J‐wire, to a 90cm (0.090" ID/0.110" OD) Sheathless PV guide catheter over a dilator. The dilator was then removed, and a long JR4 diagnostic catheter was used to select cervical vessels over a 0.035 wire and advance the guide over in a triaxial fashion. Results A total of 538 patients underwent ET during the analyzed 3‐year period, of which access was either not recorded, or was other than TRA/TFA in 23 patients (excluded from analysis). Of the remaining 515 patients, 103 had TRA‐first (all using Sheathless PV guide catheter) and 412 had TFA‐first (various guide catheters). The decision to proceed with TRA was at the discretion of the operator and was influenced by presence of bovine arch on CTA (for left anterior occlusions), favorable angle between the right subclavian and the right common carotid arteries (for right anterior occlusions), dominant right vertebral artery or favorable angle of V1 origin (for posterior circulation occlusions). Of 103 TRA cases, 71 (68.9%) were in the right carotid circulation, 18 (17.5%) ‐ in the left carotid circulation, and 14 (13.6%) in posterior circulation. TRA‐&gt;TFA conversion occurred in 5 patients (4.8%), TFA‐&gt;TRA ‐ in 1 patient (0.24%) all of which were due to prohibitive anatomy, rather than guide catheter limitations. There were no significant differences in baseline patient characteristics between the TRA and TFA groups. Angiographic outcomes (TICI 2B or greater) were similar for TRA vs TFA (96.1% vs 93.9%, p=0.39), as were good clinical outcome (discharge mRS 0‐2) rates (58% vs 55.4%, p=0.63). There was a trend towards shorter PT‐RT with TRA (29.5 min vs 38.3 min) although it did not reach statistical significance (p=0.11). No access‐related complications were noted with TRA. Conclusion Transradial thrombectomy using Sheathless PV Guide catheter is safe, effective, and offers substantial cost‐savings and shorter procedural times with low rate of access conversions, similar to other reported TRA thrombectomy series. Randomized trials are needed to validate its rates of technical success and complications against other frequently‐used TRA guide catheters.

Integration of a gas pressure chamber on a reciprocal tribometer for experiments at ambient pressures up to 10 bar

PurposeThis study aims to focus on the development of an experimental setup for testing tribological pairings under a gas atmosphere at pressures up to 10 bar.Design/methodology/approachA pressure chamber allowing oscillating movement through an outer shaft was constructed and mounted on an oscillating tribometer. Due to a metal spring bellows system, a methodology for the evaluation of the coefficient of friction values separately from the spring forces was developed.FindingsThe selected material concept was qualitatively and quantitatively assessed. An evaluation of the static and the dynamic coefficient of friction was performed, which was crucial for the understanding of the adhesion effects of the tested material pairing. The amount of information that is lost due to averaging the measured friction values is higher than one would expect.Originality/valueThe developed experimental setup is unique and, compared with the existing tribometers for testing under gas ambient pressures, allows testing under contact conditions that are closer to real applications, such as compressors and expanders. An in-depth observation of the adhesion and stick–slip effects of the tested material pairings is possible as well.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2023-0173/

Numerical study of the fire-smoke temperature law in the shaft of a high-rise building under the chimney effect in winter

Shaft structures in high-rise buildings may increase fire coverage due to chimney effects. However, few previous studies have considered the motion of the flue gas under the combined effect of the chimney effect and thermal buoyancy. So, we set a continuous gradient differential pressure opening based on the characteristics of the chimney effect in winter. The CFD method is used to simulate 12 operating conditions with different fire source locations and rates of heat release from the ignition source. We compare and analyze the temperature rise, the flue gas rise law and the variation of the thermal pressure difference between the inner and outer shafts for different fire source powers. The results show that, in the case of low-floor fires, the range of temperature appreciation and fluctuation at the local measurement point increases with the fire power and the distribution of temperature appreciation decreases with the height. The relationship between the dimensionless time and the dimensionless height of the flue gas layer is exponential for different fire position conditions. The fire causes the neutral surface to shift, and below the original neutral surface, the higher the position of the fire source, the more pronounced the shift of the neutral surface.

Effect of a constrictor plate on behavior of a model steel pipe pile driven in dense sand

This study investigates the effect of a constrictor plate on the drivability and load-carrying capacity of open-ended pipe piles via a series of model pile tests. The model pile had an outer diameter of 88.9 mm and was driven in a dense sand to a depth of 670 mm using an impact hammer. Soil plug lengths were measured using a laser distance meter for the entire process of the pile driving. The model pile further employed a double-wall system to separately measure the annulus resistance, soil plug resistance, and outer shaft resistance. Two tests with a constrictor plate located at 98.4 mm and 200 mm above the pile base and one test without a constrictor plate were performed. The piles with a constrictor plate required about 15–20% more pile driving energy than the pile without a constrictor plate. Results from static load tests showed that the piles with a constrictor plate were able to resist more axial loads than the pile without a constrictor plate by about 25–38%.

Prediction method based on strain monitoring for thread root crack in high pressure hydraulic fracturing manifold

There is a high stress concentration at the connection threads of high-pressure manifolds. Under the action of internal pressure(Pint) and rapid vibration, the root of the thread is prone to fatigue cracking. To study the variation in the damage of a high-pressure manifold with connection threading, this paper first analyzed the strain of the manifold with different Pint and with or without defects at different positions on the outer wall shaft. The potential fatigue crack damage of a high-pressure manifold of a hydraulic fracturing truck was monitored and analyzed by strain testing technology. The variation of the strain signals of defected and defect-free high-pressure pipe fittings were compared. The damage stress concentration point of the connection thread of the high-pressure manifold was analyzed. When there is a crack at the root of the thread, results show that there is a large difference in strain in the axial direction of the crack compared to the strain in threading thread without a crack. Meanwhile, the strain concentration coefficients of different stress concentration points change regularly. In this paper, the damage state of the thread is analyzed by strain monitoring. The results can provide a theoretical and practical basis for the prediction of root cracks in connection threads.

Physical Testing of a High-Speed Helicoaxial Pump for High Gas Volume Fraction Operation

Summary High-speed-rotor dynamic pump operation for downhole or surface production is required and also beneficial to handle very high gas volume fraction (GVF) flows. Operating speeds of these pumps can be in excess of twice those of conventional pumps. This study presents results showing that a high-speed helicoaxial pump (HAP) can operate satisfactorily at intake GVFs of up to 98%. The findings increase capabilities of field engineers and operators to boost and maximize production from high gas content wells. The HAPs tested had a 4-in. housing outer diameter (OD) and shaft rotational speed of 6,000 revolutions per minute (RPM). HAP rotor and diffuser clearances were 0.010 and 0.020 in. A water sprayer was included at the HAP inlet. Water volume flow rates were held constant and that for air was varied. Water volume flow rate range was 63 to 143 B/D, and 549 to 3,238 B/D for air. Intake pressures varied from 14 to 76 psig, and average temperature across the HAPs was 20°C. The corresponding measurements were recorded during observed stable pump operation for each test point. The results showed that the HAPs had stable operation during the tests for intake GVF range from 79 to 98%. The range of dimensionless pressure boost (DPB) was between 0.0184 and 0.0501, indicating that at such high speeds, the HAPs were able to add energy to the fluid even at high intake GVFs. For a given intake gas/liquid density ratio, the DPB decreased with increasing intake GVF. For the same liquid flow coefficient and intake GVF, increasing the intake gas/liquid density ratio increased the DPB of the HAP. The higher intake density ratio enhanced the HAP’s capability to provide positive pressure boost up to an intake GVF just above 98%. It was also observed that the HAP with the tighter diffuser-rotor clearance of 0.010 in. had a higher pressure boosting capability than the HAP with 0.020-in. diffuser-rotor clearance. Proper pump intake flow conditioning and homogenization using the water spray facilitated stable operation of the HAPs. Overall and in conclusion, running HAPs at high speeds in addition to optimizing certain features of the HAPs can result in stable pump operation and enhanced pressure boosting in high GVF flows. This study mainly highlights the importance of operating HAPs at high speeds of up to 6,000 RPM. Tightening clearances between rotordynamic components and tailored inlet flow conditioning are also additional features that enhance pressure boosting. This architecture opens up opportunities for field operators and engineering personnel to maximize hydrocarbon production from their very high gas content field assets, thereby increasing the economic bottom line for the stakeholders.

Obstacle Modeling and Structural Optimization of Four-Track Twin-Rocker Rescue Robot

In order to achieve the best obstacle surmounting performance of a mobile robot in the rescue environment, a four-track twin-rocker bionic rescue robot with an inner and outer concentric shaft was designed in this paper. From the viewpoint of dynamics, the motion process of the mass center of the robot when climbing steps forward and backward was studied. The maximum obstacle height of the robot was calculated. The relationship between the elevation angle of the car body, the swing angle of the rocker arm and the height of the steps was analyzed by simulation. The simulation results show that the maximum forward and reverse obstacle crossing heights were 92.99 mm and 155.82 mm, respectively. Obstacle climbing experiments of the designed robot prototype were carried out. It was found that the measured maximum height of the step was 95 mm, and the measured maximum height of the reverse obstacle was 165 mm. Finally, bionic particle swarm optimization was used to optimize the structural parameters of the rocker arm with an optimal length of 315.2 mm. The study of this paper can be referenced for the design and analysis of obstacle surmounting rescue robots with similar structures.

Interface shear behavior of a shaft lining concrete-high density polyethylene material under different pre-imposed normal stresses.

As an important part of a double-layer shaft lining in China, a polyethylene sandwich can reduce or even eliminate the constraint effect on the inner shaft lining, which is confined by the outer shaft lining, thus improving the integrity of the inner shaft lining concrete. To reveal the interface shear mechanism of the concrete-high density polyethylene (HDPE) material, a series of 16 direct shear tests were performed under high normal loads (0.6~4 MPa) with four different surface morphologies. The experimental results showed that the interfaces exhibit a clear strain-softening property during shear, and the shear strength increases linearly with increasing normal stress. Three shearing mechanisms, plowing, localized plastic deformation, and dilatancy, were observed in these experiments. The research results are of great theoretical and practical value for understanding the shear mechanism and predicting the shear strength of a shaft lining concrete-HDPE interface under high normal stress.

Study of the Impact of E-Machine in Hybrid Dual Clutch Transmission Powertrain

Recent studies show that hybrid powertrains with dual clutch transmission are becoming more common. This is mainly influenced by the fact that they have higher efficiency, allow power-on shifting, and are more compact. However, the electric motor attached to the primary shaft of the transmission might represent some critical issues in statics and dynamics due to additional torque, inertia, and working irregularities. This paper aims to investigate the influence of the electric motor integration in the transmission on the reliability of the overall system. The focus is on the investigation of potential over stresses of the ICE bearings due to the bending of the gearbox primary shaft. To achieve the aim, the static and the rotor dynamic analysis of the inner and outer primary shafts is performed. The numerical analyses show the potential critical issues that can arise from the excessive manufacturing and assembling tolerances, the interaction of the e-machine torque irregularities and inertia with the bending dynamics of the primary shafts.

Research on the fault analysis method of belt conveyor idlers based on sound and thermal infrared image features

The large number, scattered distribution, and complex working environment of idlers makes their faults challenging to detect. In this paper, a fault analysis method of belt conveyor idlers based on sound and thermal infrared image (TII) features is proposed. According to 18 classes of idler sound and TII data, the time-domain (TD) features of sound signals are analysed using statistical methods, the frequency-domain (FD) and time-frequency-domain (TFD) features of sound signals are analysed with the quantization and dimension reduction method based on Fisher’s linear discriminant, and the TII features are analysed using statistical methods. The analysis results show that final and catastrophic faults can be detected by using FD features of idler sound and TII temperature rise of the idler outer load area and shaft end, and TFD features of idler sound signals can be used to detect typical bearing defects, which features high reliability, low cost, and easy implementation.

Mechanical analysis of cluster-grain separator device of a new head of paddy harvesting machine

This paper presents stress and strain analysis of outer shaft shoulder (OSS) and inner shaft shoulder (ISS) of a new paddy harvesting head (PHH) using finite element method (FEM). Snapping grain unit is a part of this head, with OSS and ISS as its members. The analysis was performed using the ABAQUS software with Dynamics Explicit Solution Method. Eight-node block and four-node tetrahedral elements were used to mesh the parts of the head. After the analyses, the stress and strain curves, and their maximum values were estimated for various parts. Analytical method was used to verify the FEM results and to calculate the factor of safety (FS) of the OSS and ISS components and also to estimate the number of cycles to failure of each component. The maximum amount of force applied to each tooth of shoulder was 4.29 Nmm-1. The maximum stress in both shoulders was obtained as 44.43 MPa. Other results showed, fatigue factors of safety for all components were less than their relevant yield factor of safety. Therefore, the fatigue in components would occur first. The study showed the predicted life for OSS and ISS components is more than 106 cycles, thus the components have an infinite-life. A fitted regression line to the data showed that the calculated stresses from analytical method lie within bounds of 7.89 % of the predicted values with a coefficient of determination of 0.98. Hence, it could be concluded that there is a good agreement between the analytical and FEM results.

Non-destructive Detection of the Anomalies and Thickness of a Shaft Using GPR

Ground penetrating radar (GPR) has been proven to be one of the most promising non-destructive methods that has been widely used in engineering quality inspections and condition assessments of underground structures. This paper reports an application study of GPR that presents a comprehensive survey of the auxiliary shaft of the Anli coal mine in China. During shaft installation, water gushing with a maximum inflow rate of approximately 16.0 m3/h occurred, and thus, it was urgent to determine the distribution range of anomalies and evaluate the lining thickness of the shaft to provide precise technical guidance for later treatments. A GPR grid scan was carried out by towing the antenna along 6 vertical measuring lines and 11 orthogonal circular measuring lines on the shaft surface. The GPR results show that the anomalies experienced by the shaft are voids, uncompacted areas and water bodies. Most anomalies were located in the outer shaft lining and surrounding soil. A vast majority of the shaft lining thickness reach its designed value, with a qualified rate of 91.2% for the inner shaft lining and 89.9% for the outer shaft lining, and the outer shaft lining exhibited inferior smoothness and uniformity. Under the guidance of the GPR results, a grouting treatment was carried out to water seal and strengthen the shaft lining, which, consequently, reduced the water inflow rate by 90%. The favourable grouting effect demonstrates that the GPR method can feasibly and successfully reflect the shaft lining and anomalies in shaft assessments. This engineering practice could serve as a case study reference for investigating any similar underground structure in the future.

Axial resistance of open-ended pipe pile driven in gravelly sand

A full-scale, double-wall, open-ended pipe pile with a diameter, B = 660 mm was densely instrumented with a combination of electrical-resistance and vibrating-wire strain gauges. The test pile was driven into a gravelly sand soil profile to a depth of 30·48 m and then statically and dynamically load tested. The double-wall instrumentation allows independent measurements of the outer shaft, inner shaft (plug) and annulus resistances during a static load test. The residual loads locked in the pile after driving were measured and considered in the correction of the resistance components. The load–settlement curve, load transfer curves and the profile of the unit limit shaft resistance were obtained from the static load test measurements. Two cone penetration test-based methods were used to estimate the resistance of the test pile, which was compared with that obtained from the static load test. Both methods provide good estimates for the unit shaft resistance in sandy layers with low gravel content (&lt;20%), but significantly overestimate the unit shaft resistance mobilised in soil with high gravel content (&gt;30%). The estimated base resistances by both methods match well that measured in the static load test.

Pulse gas-assisted multi-needle electrospinning of nanofibers

Multi-needle electrospinning is an effective method to increase the productivity of nanofibers. In this paper, the number of single-needle jets was increased to further improve the production efficiency. As the traditional method for increasing the number of single-needle jets has poor controllability and persistence, we proposed a gas-assisted method to increase the yield of nanofibers. A coaxial gas auxiliary needle was designed with an intermediate shaft supplied gas and the outer shaft supplied solution. Innovatively using pulse gas to produce continuous and stable bubbles which are ruptured on the needle. The liquid film is continuously disturbed, which generates jets in the electric field, thereby increasing the number of jets of a single needle. After optimization of the single-needle gas-assisted electrospinning process, the stable spraying process of 16-pin multi-needle electrospinning has been realized. The gas-assisted electrospinning productivity was 4.7 times higher than that of without gas assistance. It provided a new idea for improving the stable production of the multi-needle electrospinning.

An analytical investigation of elastic-plastic deformation of FGM hollow rotors under a high centrifugal effect

Functionally graded material shafts are the main part of many modern rotary machines such as turbines and electric motors. The purpose of this study is to present an analytical solution of the elastic-plastic deformation of functionally graded material hollow rotor under a high centrifugal effect and finally determine the maximum allowed angular velocity of a hollow functionally graded material rotating shaft. Introducing non-dimensional parameters, the equilibrium equation has been analytically solved. The results for variable material properties are compared with the homogeneous rotor and the case in which Young’s modulus is the only variable while density and yield stress are considered to be constant. It is shown that material variation has a considerable effect on the stress and strain components and radial displacement. Considering variable density and yield stress causes yielding onset from inner, outer, or simultaneously from both inner and outer rotor shaft radius in contrast to earlier researches that modulus of elasticity was the only variable. The effects of the density on the failure of a functionally graded material elastic fully plastic in a hollow rotating shaft are investigated for the first time in this study with regard to Tresca’s yield criterial. Numerical simulations are used to verify the derived formulations which are in satisfying agreement.