Deformation Of Shaft Research Articles

Nowa koncepcja przyrządu do pomiaru odkształceń ramion wykorbień wałów korbowych metodą symetryczną

The patent pending design of the crank shaft deformation measuring device by means of the symmetric method, was presented. The new solution eliminates imperfections and inaccuracies resulting from the method currently used for this purpose, and enables correct assessment of the crankshaft positioning in main bearings.

Nonlinear vibration of in-extensional rotating shaft under electromagnetic load

In this paper, nonlinear vibration of a simply supported rotating shaft with nonlinear curvature and gyroscopic effect under transversely electromagnetic load is investigated. It is assumed that the shaft is inextensible and electromagnetic load depends on the shaft deformations. The non-linear partial equations of motion derived by Hamilton's principle are solved using the succession of Galerkin and the multiple-scales perturbation method. By properly tuning the primary resonance of the system, the modulation equations of the rotating shaft are obtained. Stability of fixed points and saddle-node bifurcation of steady-state solution are presented in frequency response diagrams. Results show that the magnetic load has noticeable effects on the steady state response of the rotating shaft. Also, the change in qualitative nature (hardening- type, and softening- type) of primary resonance curves is observed by considering the geometric nonlinearity effects.

Vibration Behavior of Gravity-Loaded Whirling Micro-Scale Shafts Influenced by an Axial Magnetic Field

Some high-speed rotating micro-machines and micro-vibration devices rely on the use of whirling micro-shafts subject to the effect of gravity and magnetic fields. At present, the consequences of the interaction between the elastic deformation of such shafts and the magnetic/gravitational field effects remain unresolved. Focusing on micro-scale whirling shafts with very high torsional rigidity, this study presents a theoretical treatment grounded in the theory of micro-continuum elasticity to examine the ramification of this interaction. The differential transformation method (DTM) is used to obtain extensive numerical results for qualitative assessments of the magnetic-gravitational effects interaction on standing, hanging and horizontally positioned spinning micro-scale shafts. The influence of bearing-support flexibility on the response of the whirling micro-shaft is also considered with rotational and translational springs. The gravitational sag reduces the stability of whirling standing micro-shafts and increases that of the hanging micro-shafts. Further, for all the micro-shafts configurations investigated, the magnetic field is observed to stiffen the response of the shaft and favorably shifts the critical points of vibration of the whirling shafts forward.

Adaptive real-time model on thermal error of ball screw feed drive systems of CNC machine tools

The positioning error of ball screw feed drive systems is mostly caused by thermal deformation of the ball screw shaft in machine tool feed systems. This paper presents an adaptive real-time model (ARTM) for predicting the temperature transient distribution and thermal error distribution of the ball screw shaft. FEM integrated with the Monte Carlo method is applied to determining the heat generation rates of two bearings, moving nut and two guides in the ball screw feed system. Then based on the data of the FEM calculations, an exponential function of the feed velocity and time is used to describe variation of the temperature difference between the measured surface point and the center of the kinematical pair with time. Finally, a numerical forecasting algorithm is developed to predict the thermal characteristics of the screw shaft and its effectiveness is verified by the experiments.

Outcomes of Isolated Radial Osteotomy for Volar Distal Radioulnar Joint Instability Following Radial Malunion in Children.

The radius bone has a slight dorsoradial bow that allows for full forearm pronosupination around the ulna. However, radial malunion can lead to reversal of the radial bowandsubsequent volar instability of the distal radioulnar joint (DRUJ), predominantly in supination. This study assessed the outcomes of corrective radial osteotomy for volar DRUJ instability after radial malunion in children. The charts of 7 children (2 boys and 5 girls) treated with corrective radial osteotomy for volar DRUJ instability after a radius fracture or deformity were reviewed. Demographic, diagnostic, treatment, and complication information was collected for each patient. Radiographs at initial injury, fracture union, diagnosis of DRUJ instability, and final follow-up were reviewed for radiographic measurements of radial deformity and subsequent correction. Fractures included 4 distal radius, 2 proximal radius, and 1 plastic deformation of the radial shaft. Volar DRUJ instability was diagnosed an average of 2.7 years (range, 1-6 years) after fracture at an average age of 13.6 years (range, 12-17 years). Two of 7 patients hadpersistent symptoms despite having undergone previous soft tissue surgery for DRUJ instability. Radial osteotomy was performed on all patients (3 dorsal and 4 volar approaches), with an average sagittal plane correction of 23° ± 10° (range, 14° to 40°). Osteotomy site varied (3proximal third, 1 middle third, and 3 distal third) based on the apex of maximal deformity. Patients were observed an average of 2.3 years (range, 1.0-5.7 years). At final follow-up, all patients had a stable DRUJ and no patient required soft tissue stabilization. Apex volar malunion of radial fractures may result in volar instability of the DRUJ. Radial osteotomy restored the normal apex dorsal radial bow and effectively stabilized the DRUJ without the need for soft tissue repair. Osteotomy should be tailored to the specific site of radiographic deformity. Therapeutic V.

Новые технологические возможности отделочно-упрочняющей обработки поверхностным пластическим деформированием

The paper reports the results of the strengthening simulation process. A new kinematics of deforming rollers ensuring a surface plastic deformation of shafts of low rigidity was considered. On the basis of the theory of low elasto-plastic deforma-tions and a method of finite elements there were formed simulators of a strengthening process allowing the definition of a stressed state in a sample depending on the form and kinematics of an indenter. With the aid of ANSYSWB software there was considered the impact of some circuits of deformation upon a stressed state: running-in by rolling, running-in by slip, running-in by one and two rollers with the rotation with regard to a diametrical axis. On the basis of simulation results it was revealed that the basic factors affecting a stress-strain state of parts are geometry, a form, a mutual location of elements of a tool deformed and their kinematics with regard to a part worked.

Shear performance of bolted side-plated reinforced concrete beams

Although the bolted side-plating (BSP) technique is feasible to upgrade the shear capacity of reinforced concrete (RC) beams, related studies on its strengthening effect have yet to be sufficient. Therefore, an experimental study of seven specimens was conducted to investigate the shear performance of BSP beams. The failure mode was found shifting from shear–tension to shear–compression after strengthening. The decrease of bolt spacing, the increase of plate breadth and thickness improved the shear capacity, stiffness and ductility effectively. Although the additional stiffeners improved the stiffness considerably, it exhibited no obvious improvement in the shear capacity and caused a serious reduction in ductility. Due to the shear deformation of bolt shaft and the tensile principal stress in the steel plates that was perpendicular to the main diagonal crack, uneven relative longitudinal and transverse slips existed on the interface between the bolted steel plates and the RC beams. An analytical model was developed according to the force equilibrium and deformation compatibility of the beam segment in the shear span. A design procedure, which can be conducted conveniently using ordinary computing software or even a calculator by structural engineers in their strengthening design practise, was also provided to estimate the shear bearing capacity of BSP beams.

Seeding and transgenic overexpression of alpha‐synuclein triggers dendritic spine pathology in the neocortex

Although misfolded and aggregated α‐synuclein (α‐syn) is recognized in the disease progression of synucleinopathies, its role in the impairment of cortical circuitries and synaptic plasticity remains incompletely understood. We investigated how α‐synuclein accumulation affects synaptic plasticity in the mouse somatosensory cortex using two distinct approaches. Long‐term in vivo imaging of apical dendrites was performed in mice overexpressing wild‐type human α‐synuclein. Additionally, intracranial injection of preformed α‐synuclein fibrils was performed to induce cortical α‐syn pathology. We find that α‐synuclein overexpressing mice show decreased spine density and abnormalities in spine dynamics in an age‐dependent manner. We also provide evidence for the detrimental effects of seeded α‐synuclein aggregates on dendritic architecture. We observed spine loss as well as dystrophic deformation of dendritic shafts in layer V pyramidal neurons. Our results provide a link to the pathophysiology underlying dementia associated with synucleinopathies and may enable the evaluation of potential drug candidates on dendritic spine pathology in vivo.

An improved high precision measuring method for shaft bending deflection

• An available measuring method is presented for columnar parts bending deflection. • High precision measuring algorithm is proposed after strict mathematical analysis. • Closed analytic solution method is gotten and won't produce any principle error. • Parameters sensitivity analysis is studied for the method adaptability assessment. • Experimental calibration method is provided and experimental validation is made. The circular-section columnar parts, such as shaft, rod and pipe etc., are widely used in all kinds of machines. The bending deformation of such parts will seriously affect the assembly precision and working performance of the machines. A high efficiency and precision measuring method for bending deflection is needed. With a classic contact-detection mechanism at low cost composed of a displacement sensor, a lever and a shaft supporting device, a high precision measuring algorithm is proposed and deduced after strict mathematical analysis in this paper, and which is a closed analytic algorithm and will not produce any principle error. The parameters sensitivity auditing is carried out and the result shows the measuring method has high adaptability. Furthermore, the corresponding experimental calibration method of the current measurement technology is provided, and an experimental validation on the bending deformation of a particular shaft is carried out. The result shows in depth the proposed method has high accuracy.

Comparison of Thermal Deformation of Steel and CFRP Shafts for Machine Tool Spindles

Comparison of Thermal Deformation of Steel and CFRP Shafts for Machine Tool Spindles

Analysis of Stresses in Elements of Hub Reduction Gear of TREKOL-39041Off-road Vehicle

This article presents the analysis of results of the experimental research aimed at the determination of loading of the gearwheel shaft in rear axle hub reducer of the off-road vehicle with ultra-low-pressure tires TREKOL-39041. The comparison of the experimental data with the data from other authors and with the computational data was made. The obtained experimental data was compared to the experimental and computational data for UAZ-31512 drivetrain details loading. The main details of this vehicle were used in the structure of the considered all-terrain vehicle. The plastic deformation of shaft of hub reduction gear was found. The results of calculations show that the operation loads in this shaft exceed the limit tensions of the shaft material. It can be explained by impact of ultra-low pressure tires.

Gear Clutch with Modified Tooth Profiles

The article presents the results of research of modification design for tooth clutch with low sensitivity to elastic deformation of shafts and assembly errors. The implementation of these conditions by the use of circular tooth profiles is carried out. Based on the given boundary conditions by the limit values of radii of curvature in the longitudinal direction (barrel modification) and the teeth height (profile modification) are defined. According to the results of comparative calculations, recommendations on the selection the parameters of the longitudinal and profile modifications teeth are given. Using the proposed development will enhance the ability of compensating tooth clutch in comparison with a standard analogue.

Dynamic analysis of a geared rotor-bearing system with translational motion due to shaft deformation under residual shaft bow effect

In this paper, the dynamic response of a spur geared rotor-bearing system has been studied when the gear set has translational motion due to shaft deformation and residual shaft bow effect. A new dynamic model for the geared rotor-bearing system, considering translational motion and residual shaft bow effect, is proposed, in which the distance between the centers of two gears varies with time. Therefore, the proposed model regards gear pressure angle and contact ratio as time-varying variables, while the previous model regards them as constant. A finite element model of the geared rotor-bearing system developed, the equations of motion are obtained by applying Lagrange’s equation. After deriving nonlinear equations of motion for the geared rotor-bearing system, the dynamic responses are computed by applying the fourth-order Runge-Kutta numerical method. The dynamic response including lateral response of two gears, gear pressure angle and contact ratio with different phase angle between two residual shafts are investigated. The results show that the magnitude of the residual shaft bow, the phase angle between two residual shafts will significantly affect gear pressure angle and contact ratio. This new model produces more accurate dynamic responses in comparison to those of the previous model.

Two-Stage Surgical Treatment of Complex Femoral Deformities with Severe Coxa Vara in Polyostotic Fibrous Dysplasia.

For complex femoral deformities in patients affected by polyostotic fibrous dysplasia and coxa vara associated with shepherd's crook deformity of the femoral shaft, the correct treatment is stabilization with an interlocking cervicodiaphyseal nail after correction of all of the femoral deformities. Evaluate the patient radiographically and select the hardware. Position the patient on the traction table. Expose the lateral aspect of the proximal part of the femur and mark the position of both the blade-plate and the osteotomy. Prepare the slot for the blade, perform the osteotomy, and correct the valgus alignment of the proximal part of the femur. Check postoperative bleeding, provide blood transfusions if needed, and have the patient resume walking. Study the patient radiographically, simulate the osteotomies, perform another assessment of lower-limb length, and select the hardware. Position the patient on the traction table and expose the lateral aspect of the femur from the tip of the greater trochanter to the level of the most distal planned osteotomy. All of the osteotomies are performed, and a medullary canal is drilled in each femoral fragment. Introduce the nail into the osteotomy fragments and insert the spiral blade and distal locking screws. Check postoperative bleeding, which is usually marked; administer blood transfusions as needed; and have the patient resume walking. We performed this surgery on 13 femora in 11 patients.

Calculation methods of investigating the surface layer of thin-walled shafts hardened by methods of surface plastic deformation

Calculation methods of investigating the residual stress-strain state of the surface layer of shafts hardened by shot peening and diamond burnishing are discussed in the paper. Shafts manufactured at aircraft plants are mostly thin-walled. In addition high requirements are imposed on the accuracy of their geometric dimensions and shape. Ensuring the fatigue resistance of shafts is achieved by applying hardening treatment. Hardening treatment residual stresses result in residual deformation of shafts often exceeding manufacturing tolerances. The models and approaches proposed in this paper make it possible to predict computationally the residual stress-strain state of the surface layer after diamond burnishing as well as technological residual deformations of the shafts caused by residual stress. They also allow adjusting the modes of shot peening and diamond burnishing at the stage of process development. The work was carried out for a shaft made of VT-22 and EP517-SH materials. The results of the investigation show that the use of preliminary numerical analysis of treatment modes makes it possible to ensure residual deformations of the most critical sections of the shafts and seating surfaces for bearings within manufacturing tolerances and also to reduce tensile residual stress on the shaft surface after diamond burnishing.

A prospective multicentric international study on the surgical outcomes and patients' satisfaction rates of the 'sliding' technique for end-stage Peyronie's disease with severe shortening of the penis and erectile dysfunction.

To report the results from a prospective multicentric study of patients with Peyronie's disease (PD) treated with the 'sliding' technique (ST). From June 2010 to January 2014, 28 consecutive patients affected by stable PD with severe penile shortening and end-stage erectile dysfunction (ED) were enrolled in three European PD tertiary referral centres. The validated International Index of Erectile Function (IIEF) questionnaire, the Sexual Encounter Profile (SEP) Questions 2 and 3, and the Peyronie's disease questionnaire (PDQ) were completed preoperatively by all patients. At the follow-up visits (at 3, 6 and 12 months), the IIEF, the SEP Questions 2 and 3, the PDQ, and the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) were completed. The outcome analysis was focused on penile length restoration, and intra- and postoperative complications classified according the Clavien-Dindo Classification. The mean (range) follow-up was 37 (9-60) months. A malleable penile prosthesis (PP) was implanted in seven patients, while an inflatable three-pieces PP was placed in the remainder. In the case of inflatable PP implantation, porcine small intestinal submucosa and acellular porcine dermal matrix were used to cover the tunical defects. While in patients undergoing malleable PP implantation, collagen-fibrin sponge was used. The mean operative time was 145 min in the inflatable PP group and 115 min in the malleable PP group. There were no intraoperative complications. Postoperative complications included profuse bleeding requiring a blood transfusion in one patient (3.5%) on anticoagulation therapy for a mechanical heart valve (Grade II) and PP infection requiring the removal of the device (7%) (Grade III). There were no late recurrences of the shaft deformation. The postoperative functional data showed a progressive improvement in the score of all questionnaires, peaking at 12 months postoperatively. The mean (range) penile lengthening was 3.2 (2.5-4) cm and no patient reported recurrence of the curvature. The present series suggests that, in the hands of experienced high-volume surgeons, penile length restoration with the use of the ST represents an effective option for end-stage PD associated with ED and severe shortening of the shaft. Larger series and longer follow-up will be required to fully establish the efficacy of this procedure.

Helical gear multi-contact tooth mesh load analysis with flexible bearings and shafts

A multi-contact tooth meshing model for helical gear pairs considering bearing and shaft deformations is proposed. First, to easily incorporate into the system model, the complicated Harris\'s bearing force-displacement relationship is simplified applying a linear least square curve fit. Then, effects of shaft and bearing flexibilities on the helical gear meshing behavior are implemented through transformation matrices which contain the helical gear orientation and spatial displacement under loads. Finally, true contact lines between conjugated teeth are approximated applying a modified meshing equation that includes the influence of tooth flank displacement on the tooth contact induced by shaft and bearing displacements. Based on the model, the bearing\'s force-displacement relation is examined, and the effects of shaft deformation and external load on the multi-contact tooth mesh load distribution are also analyzed. The advantage of this work is, unlike previous works to search true contact lines through time-consuming iterative strategy, to determine true contact lines between conjugated teeth directly with presentation of deformations of bearings and shafts.

Three-Dimensional Dynamic Model of TEHD Tilting-Pad Journal Bearing—Part I: Theoretical Modeling

This paper is focused on a new modeling method of three-dimensional (3D) thermo-elasto-hydro-dynamic (TEHD) cylindrical pivot tilting-pad journal bearing (TPJB). Varying viscosity Reynolds equation and 3D energy equation are coupled via lubricant temperature and viscosity relationship. Three-dimensional finite element method (FEM) is adopted for the analysis of: (1) heat conduction in shaft and bearing pad, (2) thermal deformation of shaft and pad, (3) flexible bearing pad dynamic behavior, and (4) heat conduction, convection, and viscous shearing in thin lubricant film. For the computational efficiency, modal coordinate transformation is utilized in the flexible pad dynamic model, and pad dynamic behavior is represented only by means of modal coordinate. Fluid film thickness is calculated by a newly developed node based method, where pad arbitrary thermal and elastic deformation and journal thermal expansion are taken into account simultaneously. The main goal of this research is to provide more accurate numerical TPJB model than developed before so that the designers of rotating machinery are able to understand the bearing dynamic behavior and avoid unpredicted problem by selection of physical parameters.

The Function of the Distal Interosseous Membrane and its Relevance to the Stability of the Distal Radioulnar Joint: An Anatomical and Biomechanical Review.

The purpose of this article is to review functional anatomy and biomechanics of the distal interosseous membrane (DIOM) and its relevance to the stability of the distal radioulnar joint. The intact DIOM constrained dorsal dislocation of the radius, but it seldom constrained palmar dislocation. A residual ulnar translation deformity of the radial shaft in distal radius fractures has the potential to cause the distal radioulnar joint instability when the triangular fibrocartilage complex injury is also present, because it may result in detensioning of DIOM. Ulnar shortening with the osteotomy performed proximal to the attachment of the DIOM had a more favorable effect on stability of the DRUJ compared with the effect of distal osteotomy, especially in the presence of the distal oblique bundle (DOB). The longitudinal resistance to ulnar shortening was significantly greater in proximal shortening than in distal shortening.

Finite element and experimental analysis of pinion bracket-assembly of three gorges project ship lift

The pinion bracket-assembly (PBA) is a major part of three gorges project (TGP) ship lift drive system. The static strength, fatigue strength and stress distribution of hinge pin of PBA were analyzed by ANSYS, and the structure of PBA was optimized. The results show that after the optimization, the maximum comprehensive stress is 259.59 MPa, the maximum fatigue cumulative damage of weld joints is 0.94 and the maximum vertical deformation of hinge pin is 0.14 mm. The elastic deformation, hydropneumatic spring cylinder (HSC) load response and the vibration characteristics of PBA were studied by the bearing test when PBA bore the load caused by different water level errors. The results indicate that when the water level of ship chamber ranges from 3.4 m to 3.6 m, the vertical elastic deformation of the pinion shaft is between −8.58 and 10.50 mm. When upward outage-load(1580 kN) is imposed by the test-rack, the vertical elastic deformation of the pinion shaft is 13.42 and 14.07 mm and HSC load response is 795.80–800.80 kN. In the process of imposing load on the pinion by the test-rack, the maximum vibration amplitude and acceleration of PBA internal components are 0.37° and 2.67 rad/s2, respectively; the maximum impact on the pin caused by vibration is 19.89 kN; the pinion shaft vertical displacement and HSC load response do not fluctuate. There is a great difference between the frequency of meshing force of the pinion and the rack (1.06 Hz) and first-order natural frequency of PBA(8.41 Hz), thus PBA will not resonate. From all above, PBA meets the static strength and fatigue strength requirements. The vibration of PBA internal components has no effect on the vertical displacement of the pinion shaft, HSC load response and smooth operation of PBA. There is a liner relationship in the ratio of 2:1 between the thrust imposed by the test-rack and HSC load, thus HSC can limit the load imposed on the pinion.