Shaft Design Research Articles

Modeling and simulation of belt bucket elevator head shaft for safe life operation

This research paper presents a step by step conceptual design and life prediction approach for the design, modeling and simulation of head shaft of a belt bucket elevator, to be used for conveying grains to a height of 33.5 m and at the rate of 200 tons/h. output. For this elevator system, the force and torque acting on the head shaft as well as the bending moment were calculated. Furthermore, the diameter of each cross section of the shaft was determined taking into consideration the geometric and fatigue stress concentration factors, due to shoulders which contribute significantly to most fatigue failures of shafts. The stress induced on the shaft by the force and the factor of safety for each cross section of the shaft was calculated using the DE-Goodman criterion. The model of the shaft was created from the calculated diameters and subjected to static and fatigue analysis using SolidWorks FEA. The results were validated by comparing the values from the FEA and the calculated values for stress and factor of safety of the critical section of the shaft, which showed an equivalent value. The FEA gave a fatigue load factor greater than one, which signifies that the shaft will not go into failure mode within the infinite life cycle of the shaft. The value of the fatigue strength obtained from FEA was higher than the value for the maximum von misses stress of the shaft, this result shows that the head shaft will sustain the loading stresses over a finite life prediction. This research is significant because the stress induced forces on the head shaft from each component of the elevator system were properly identified and analyzed so as to obtain precise results for life prediction.

Design and optimization of automotive cardan shafts for industrial applications with enhanced performance and durability

A crucial part of a locomotive is the cardan shaft. A rear-wheel-drive vehicle's differential gear receives power from the engine through a spinning shaft known as a cardan shaft. The cardan shaft must turn at ever-changing angles between the gearbox and axle in order to function. High vibrations are experienced on it as a result of the constant rotation. This issue causes shafts to flex or distort. In this study, a cardan shaft's design and development are carried out. Although it is extensively beneficial in the locomotive industry, vibration is a significant issue with cardan shafts. Creo parametric software was used for developing the design, while Ansys was used to analyze it. Using Ansys software's modal analysis, verify the natural frequency. It is then contrasted with the different shaft cut-out geometries.

ELASTIC EMBEDMENT SUPPORT: A NOVEL APPROACH TO THE PRELIMINARY DESIGN OF SHAFTS

This study discusses the introduction of elastic embedment support in the preliminary design of shafts. The preliminary design of shafts idealizes the supports by considering them mobile articulated support, fixed articulated support, or embedded support. In several cases, these idealizations deviate from reality. While articulated supports produce internal forces, tensions, deflections, and gradients greater than real, embedded supports lead to internal forces, stresses, deflections, and deformation angles lower than real. These deviations in typical shaft design schemes have been corrected with safety factors. This study presents a novel elastic embedment support using a dimensionless stiffness coefficient to improve the preliminary shaft design and obtain more adequate results, with shaft dimensions more suitable for the acting loads. These results were assessed with the conventional analysis schemes for three bearing types for shaft lengths between 200 to 1000 mm. Contrasted to the conventional model articulating both shaft supports, the bending moment is significantly lower when considering the elastic embedment. The maximum bending moment from the conventional model is 65% higher than that obtained with the elastic embedment for single-row ball bearings, 58% higher for tapered roller bearings, and 40% higher for double-row ball bearings. Furthermore, the bending moment increases its significance with the shaft length. Thus, considering the bearing stiffness for the three rolling bearing types results in shaft support bending moments of 10 to 21% of the maximum bending moment obtained from the conventional model. These differences significantly impact the fatigue life estimation of the shaft because the deflection obtained from the conventional model is higher than that for the elastic embedded support, which impacts the fatigue life estimation of the shaft. Therefore, it is concluded that using the elastic embedment support in the preliminary shaft design, reduces the uncertainty in the results, leading to lower security coefficients. Keywords: Preliminary Shaft Design, Embedded Support, Articulated Support DOI： https://doi.org/10.35741/issn.0258-2724.58.1.47

Architectural features of the Ancient Egyptian rock-cut tomb of Kaemnefret (LG 63) on the Eastern Field of the Giza Necropolis

The article analyses the structural and planning aspects of the ancient Egyptian rock-cut tomb of royal official Kaemnefret (LG 63) in the Eastern Field of the Giza Necropolis, including two hypotheses of plan development, characteristics of the burial shafts, possible reasons for the absence of “false doors”, purpose of the two passages from room 63A to room 63B and identity of the four statues. The distinctive feature of the tomb is the location of the mouth of a burial shaft outside the chapel, which is not typical for rock-cut tombs and may be an imitation of a mastaba, as proved by the design of some burial shafts. The main question addressed in the article concerns the order in which the two groups of shafts located in rooms 63A and 63B were constructed. Thus, two hypotheses on the development of the tomb were suggested. The main hypothesis supports the idea of the primary construction of the shafts in room 63B and only the subsequent emergence of additional burial shafts in room 63A. The alternative hypothesis is based on the idea of a reverse sequence. The absence of a false door in the tomb is most possibly related to its destruction during the reconstruction process; previously, it had probably existed in place of one of the two passages to room 63B. As a result, most of the architectural criteria allow to date the tomb fairly broadly to the V–VIth Dynasties and only a few details allow to narrow the dating to the late Vth – VIth Dynasties.

Multi-objective optimisation design of cross shaft based on Kriging response surface optimisation model

Multi-objective optimisation design of cross shaft based on Kriging response surface optimisation model

Research on Headway of Ventilation Shaft Design under Different Control Modes

Tracking headway time is an important target the Metro capacity. In order to meet the 150 second design capacity in the Shanghai Chongming Line long tunnel section, this article firstly analyzes the train tracking headway time under different ventilation shaft control modes. Then, it develops a simulation tool for optimizing the location of ventilation shafts in long tunnel sections. And it develops different tracking control model algorithms for train in the ventilation shaft sections. Finally, it takes the long tunnel section between Changxingdao Station and Chenjiazhen Station in the Shanghai Chongming Line as an example to demonstrate the usability of this simulation system and the reference value of simulation results.

Characteristics of air flow driven by the water free surface in a free-flow spillway tunnel

Air is transported downstream by the water flow in a free-flow spillway tunnel, resulting in high negative pressure, which causes gate vibration and cavitation. In this research work, a physical model of a free-flow spillway tunnel was used to investigate the effects of water surface velocity and the area residual of tunnel cross sections on air movements. The results demonstrate that the air velocity distribution forms an S-shaped curve. As the water surface velocity increases or the area residual decreases, the air velocity increases, and the relative action height of the drag force of water flow on the air increases as well. The air velocity distribution is divided into two exponential distributions at the position where the air velocity drops by 0.2 times that of the water surface velocity. Two formulas for calculating the air velocity of the corresponding exponential distributions are developed. Subsequently, an algorithm for the air demand is presented, and the relative error compared to the reference data was less than ±20%. These results provide a reference for free-flow spillway tunnel ventilation shaft design.

Combined Side and Base Resistance in Rock-Socketed Drilled Shafts – A State of the Art Consensus

Both side and base resistance contribute to drilled shaft rock socket axial resistance in most cases. While there are geological settings in which mobilization of side and/or base resistance may not be reliable, those situations are the exception, not the rule. The advent of bi-directional axial load testing of rock-socketed drilled shafts has resulted in a significant body of evidence regarding the independent behavior of side and base resistance mechanisms. Accordingly, over the last two decades, a wealth of data from these full-scale load tests of rock-socketed drilled shafts demonstrate this behavior when good design, construction and quality assurance/quality control (QA/QC) procedures are followed. The authors actively attempted to identify bi-directional test results to the contrary, including a survey of the entire Deep Foundations Institute (DFI) membership, but concluded there is a notable lack of evidence that side and base resistance do not mobilize simultaneously when proper design, construction and QA/QC procedures are followed in most geologic settings. Despite this fact, there are agencies and individual engineers that continue to disregard either side or base resistance for reasons that contradict available evidence, often resulting in excessive rock socket lengths that increase costs and the risk of problems during construction. The purpose of this document is to present a summary of the recent evidence indicating mobilization of combined side and base resistances at small, compatible displacements that are within the settlement tolerance of most structures in well-designed, constructed and inspected rock sockets. The recommended best practice for design of rock-socketed drilled shafts is to account for both side and base resistance unless there is a valid documented reason to disregard one or the other on a project-specific basis.

Comparison Study of Aluminum Camshafts alloyed with different ratio of Silicon

There has always been a drastic requirement of innovative designs in the automotive industry. To accomplish this, advanced materials and newer techniques have been constantly utilized. Designers in the automotive industry always look forward towards innovation in design of cam shafts or innovation in its course of action. Weight reduction in automobile parts, constantly plays a major part in all automobile parts. Innovation in design of cam shafts could be brought about by the use of computer aided engineering. Currently, use of composite materials is widespread in order to bring about the required change in the property of materials. Nowadays, Aluminum-Silicon alloy is rapidly used for its greater strength-to-weight ratio, increased wear resistance, less density and its property of less thermal expansion coefficient. In the present work, three types of Aluminum-Silicon cast alloy materials Al-SiC 9, Al-SiC 10 and Al-SiC 12 were modeled using Creo Elements software. It was analysed for structural deformation; viz; stress, deformation and strain using ANSYS static structural 14.5 software. From the results obtained, it was clearly evident that the Aluminum-Silicon cast alloy Al-SiC 12 material shows low stress and deformation values among all three types of Aluminum-Silicon cast alloy materials that was taken for taken in for analysis.

Surface topography effect on tribological performance of water-lubricated journal bearing under mixed-EHL regime

Water-lubricated journal bearings (WLJB) are one of the important components of the stern tube shaft. Surface topography of WLJB is an important aspect in the design of stern tube shaft, and significantly affects the lubrication characteristics of WLJB. This work aims to investigate the effect of non-Gaussian surface topography on tribological performance of water-lubricated journal bearing (WLJB) under mixed-elastohydrodynamic lubrication (mixed-EHL) regime. The non-Gaussian flow factors, and a normalized Weibull probability density function is used to tackle the non-Gaussian roughness in hydrodynamic and asperity contact models respectively. From results, it is observed that skewness (S sk ) significantly affects both asperity contact pressure and hydrodynamic pressure along circumferential direction of bearing. It is concluded that for skewness, S sk = −1 to 1, lambda ratio falls between 1 to 3. The relation between altitude angle and skewness is established. The effect of bearing length to diameter (L/D) ratio on lubrication performance of WLJB is also discussed in detail.

Evaluation of fire smoke and heat exhaust performance of shafts by natural venting in tunnels

Theoretical analysis and numerical simulations are performed to study the smoke and heat exhaust performance of natural venting system with different shaft forms. Based on the mass conservation for the gas flow in the shaft, equations for estimating the total gas mass flow rate are derived. The methods for determining the smoke and heat exhaust efficiencies are also proposed. A numerical model is built for series of CFD simulations considering different shaft forms (length–width ratio of shaft vent and shape). The results clearly present the details of the natural venting process by displaying the temperature and velocity fields. The boundary layer separation and plug-holing phenomena are also observed. The effects of the shaft shapes on the smoke and heat exhaust efficiencies have been discussed quantitatively. It is highlighted that when the cross-sectional area of shaft is constant, a smaller length–width ratio of the shaft vent leads to higher smoke and heat exhaust efficiencies. Moreover, the smoke and heat exhaust efficiencies of cylindrical shafts are higher than those of cubic ones. The findings of this paper could provide some principles for the design of natural ventilation shaft in urban tunnels. For example, the length–width ratio of shaft vent less than 1:3 is recommended for the design of natural venting system in tunnels.

Design and Experimental Investigation of Four-Bar Dynamic Testing Machine

This project involved fabricating and experimental investigation of a dynamic testing machine for four-bar mechanisms with various applications. The simple crank rocker inversion is selected, and the kinematic design of the four-bar mechanism is done by keeping in view the Grashof rotatability criteria and the dynamic design required factoring in the forces acting on various links. The flywheel is designed to minimize the fluctuations in the torque required to drive the mechanism. DE-ASME Elliptic criteria is used for the shaft design and selection of bearing. For transmitting power from the AC motor to the crankshaft, a V belt and a pulley are used as the belt helps dampen the vibration effects in the mechanism. The linkages were fabricated, and the mechanism was assembled. ADXL335 accelerometer sensor is mounted on the apparatus to measure the acceleration of a point on the coupler. This acceleration data was then integrated using numerical techniques to estimate velocity and displacement. The model changes can be adjusted according to the dimensions of the bars and angles between the bars to simulate the performance of the mechanism. Due to the inherent offset in the sensor, an error was included in the data. However, the results obtained using such methods were satisfactory in visualizing the behaviour of data representing the system’s motion under running conditions. The errors in the result can be minimized using more advanced integration techniques and sensitive sensors for measurement and instrumentation. This research aims to contribute vital research knowledge for developing sustainable four-bar dynamic testing mechanisms.

Influence of assembly preload on bearings performance

Taking a transmission system under alternating axial load as an example, this paper builds the shafting model in Romax. By using the orthogonal experimental design method, the influence law of different factor level combinations on bearing performance is analyzed. The simulation results show that the axial assembly preload has a great influence on the contact stress load distribution in the inner raceway, the housing hole design tolerance of transition fit has a second influence, and the shaft design tolerance of interference fit has a smaller influence. The preload design parameters under service conditions are optimized: shaft design tolerance (k6), housing hole design tolerance (K6) and axial assembly preload (30 μm).

Gear Shaft Optimization Design

Multi-objective optimization design of gear shaft, first determine the design variables, gear shaft structure size mainly includes length size and radius size, gear shaft shaft diameter as the optimization variable, the equivalent force of gear shaft is an important indicator of static performance, and the gear shaft is optimized with the maximum equivalent force of gear shaft as the optimization goal.

Design, Analysis and weight optimization of LMV shaft by using AL + GF composite

Abstract: Aluminum composites are mainly used due to their lower weight and high strength among the Metal Matrix Composites. Aluminum is selected as matrix and E-glass fiber is selected as reinforcement. Fabrication of composite is done by the winding of composite method. Each shaft fabrication content of E-glass fiber and aluminum with different ratios depends on ANSYS results. The present article attempts to evaluate the mechanical properties of E-glass fiber-reinforced composite and study the effect of reinforcement on the matrix alloy through mechanical properties. The results are analyzed for different types of winding angles with an aluminum layer. The mechanical properties of composites have improved with the increase in the weight percentage of glass fiber in the aluminum matrix.

玉米联合收获机纵置滚刀式茎秆切碎装置的设计与试验

At present, the quality of chopping stalks with the use of a corn combine harvester needs improvement. Therefore, this study aims at designing a hob-type stalk chopping device to be installed under the header which can realize multiple groups of parallel longitudinal arrangements. Moreover, the device will be able to cut and crush the root and the middle and upper parts of the stalks. The performance of a finite element analysis corroborated the satisfactory strength and stiffness of the designed chopping blade as the mechanical requirements. Moreover, the influencing working and structural parameters were determined using a theoretical analysis. Regarding the test factors, i.e., the tip angle of the blades, fixed angle and the rotational speed of chopper shaft, single-factor and central composite design tests were also performed. Furthermore, the percentage of the qualified length of chopped stalk and the power consumption of cutting stalk were taken as the evaluation indexes. Accordingly, the results revealed the influencing parameters to be ordered as the spindle speed > fixed angle > tip angle of the blades. Subsequently, the parameters were optimized using the response surface method. Based on the obtained results, the optimized parameters including the spindle speed, the fixed angle and the tip angle of the blades were specified as 1050 r/min, 56°, and 40°, respectively. The experimental validation was also carried out on the optimal combination of the parameters. The qualified lengths of the chopped stalks were found to be 92.9%, which were consistent with the predicted results of the model. Hence, the test results met the design requirements.

Effect of the flow regime on the hydraulic features governing the operation of vortex drop shafts with spiral inlets.

If the operation of existing vortex drop shafts should be verified, then it is essential to know the hydraulic performance of these special structures under both subcritical and supercritical flow regimes. The purpose of the present research consisted of providing practical guidelines and recommendations for managing the hydraulic design and verification of subcritical and supercritical vortex drop shafts. The examination of various experimental results from physical model investigations allowed to show that the inlet channel and the spiral inlet behaved differently depending on the energy approach flow content. The main dissimilarity lay, however, in the functioning of the vertical shaft and the dissipation chamber. The rotation of the falling flow along the vertical shaft was more evident for approaching supercritical flows. Severe flow conditions in terms of water depths and bottom pressures could be observed in the dissipation chamber under a supercritical flow regime. The design of this special component must be carried with prudence compared with the subcritical flow regime because failure events as the chamber submergence and the crash of the bottom surface just under the shaft outlet may occur for approaching supercritical flows.

Investigation of The Effect of Design Variables on Slip Assembly: Spline Module and Slip Length

The driveshaft which transmits the power from the engine to the wheels in the motor vehicles is one of the vital elements in the driveline. Driveshafts have two basic motions depending on the road conditions, angular and axial movements. Angular movement is provided by the universal joints while the axial movement is provided by the slip assembly which involves a group of sliding components. Therefore, the slip assembly is an important part of the drive shaft. Basically, a slip assembly consists of two parts which are connected to each other by means of their spline forms. The parts can move back and forth longitudinally while they transmit the torque thanks to the connection interface of their spline forms. And so, they can slide and adjust the drive shaft lengths due to the position of the axles under road conditions.
 During the motor vehicle movement, slip assembly are subjected to torsion like the other components on the driveshaft. In this context, spline size and magnitude of the length compensation are highly important in the design process of the slip assembly. In this study, the effect of the spline size and the slip length have been investigated for the yoke shaft design, by using analytical and numerical methods in terms of shear stress. It has been observed that the analytical and the numerical methods give the similar results in shear stress on the pitch diameter of the spline. Thus, the analytical method can be preferred instead of the finite element analysis (FEA), especially considering that the FEA is a time consuming method compared to the analytical method in the design process.

An indirect method to determine nonlinearly elastic shear stress-strain constitutive relationships for nonlinear torsional vibration of nonlinearly elastic shafts

PurposeIn this paper, the authors aim to propose an effective method to indirectly determine nonlinear elastic shear stress-strain constitutive relationships for nonlinear elasticity materials, and then study the nonlinear free torsional vibration of Al–1%Si shaft.Design/methodology/approachIn this study the authors use BoxLucas1 model to fit the determined-experimentally nonlinear elastic normal stress–strain constitutive relationship curve of Al–1%Si, a typical case of isotropic nonlinear elasticity materials, and then derive its nonlinear shear stress-strain constitutive relationships based on the fitting constitutive relationships and general equations of plane-stress and plane-strain transformation. Hamilton’s principle is utilized to gain nonlinear governing equation and boundary conditions for free torsional vibration of Al–1%Si shaft. Differential quadrature method and an iterative algorithm are employed to numerically solve the gained equations of motion.Findings The effect of four variables, namely dimensionless fundamental vibration amplitude , radius and length , and nonlinear-elasticity intensity factor , on frequencies and mode shapes of the shafts is obtained. Numerical results are in good agreement with reference solutions, and show that compared with linearly elastic shear stress-strain constitutive relationships of the shafts made of the nonlinear elasticity materials, its actual nonlinearly elastic shear stress-strain constitutive relationships have smaller torsion frequencies. In addition, but having opposite hardening effect, the rest of the four variables have softening effect on nonlinearly elastic torsion frequencies. Eventually, taking into account nonlinearly elastic shear stress-strain constitutive relationships, changes of the four factors, i.e. , , and , cause inflation and deflation behaviors of mode shapes in nonlinear free torsional vibration.Originality/valueThe study could provide a reference for indirectly determining nonlinear elastic shear stress-strain constitutive relationships for nonlinear elasticity materials and for structure design of torsional shaft made of nonlinear elasticity materials.

Analysis of the Causes of Shaft Damage

The paper deals with complex material analysis of a shaft after failure. The shaft was operated as part of an "Abradable rig" device used to test the resistance of coatings at high speeds, which simulates a turboprop engine's operating conditions. The shaft is made of 16MnCr5 material with subsequent cementation. The subject of interest is a complex material analysis (i.e. control of the chemical composition of the material and complete fractographic and metallographic analysis) and verification of the shaft design. The aim of the study is a precise determination of the specific cause of component failure.