Axial Force Reduction Research Articles

Effect of Back Plate Preheating Assistance System and Deep Rolling Process on Microstructure Defects and Axial Force Reduction of Friction Stir Welded AA6061 Joint.

This study investigates the effects of a back plate preheating assistance system and deep rolling (DR) on axial force and tunnel defects during friction stir welding (FSW). Different preheating configurations-advancing side (AS), retreating side (RS), and both sides-were examined to evaluate their impact on axial force reduction, temperature distribution, and defect minimization. Axial force measurements were taken using a dynamometer, and temperature histories were recorded with a thermal camera. The results demonstrate that a preheating temperature of 200 °C is optimal, reducing axial force by 30.24% and enhancing material flow. This temperature also facilitated deeper tool penetration, especially when preheating was applied to both sides. Preheating on the AS resulted in the smallest tunnel defects, reducing defect size by 80.15% on the RS and 96.91% on the AS compared to the non-preheated condition. While DR further reduced tunnel defects, its effectiveness was limited by the proximity of defects to the surface. These findings offer significant insights for improving the FSW process.

Investigation of the effect of ultrasonic vibration on the performance of the friction drilling by FEM simulation

The friction drilling process is very important in various industries such as automotive, aerospace, and oil and gas industries. Therefore, they have always sought to find methods to improve this process. One of these methods is to optimize the application of ultrasonic vibrations in the process, and limited research has been done in this regard. The current research aims to investigate the effect of ultrasonic vibrations simultaneously with the parameters of drilling on the friction drilling process to optimize this process with the help of finite element simulation. Due to the nature of the complex transformations of the process, a Coupled Eulerian–Lagrangian model of the process was first created in the Abaqus software. Then, the process simulation was carried out in the presence and absence of ultrasonic vibrations. Rotational speed, feed rate, and amplitude of vibrations are the influencing parameters, and sheet temperature and axial force, and torque applied to the tool are the parameters investigated in this research. The results show that higher rotation speed and lower feed rate lead to a reduction of axial force and torque. Also, the application of ultrasonic vibration reduces up to 50.48% the axial force and up to 46.67% torque, and this reduction is improved by increasing the range of vibrations. The optimal mode was selected After analyzing 12 different modes based on the lowest amount of axial force and torque on the pin. It was found that the ideal mode occurs at a feed rate of 4.23 m/s and a rotation speed of 3000 rpm, with a 20-µm range. These findings and optimizing drilling parameters bring new horizons in material bonding techniques in various industries.

The Influence of Complex Flow on Axial Force in Rotor-Stator Cavity of Centrifugal Compressor with Radial Ribs

Abstract Research shows radial ribs can reduce the axial force acting on the centrifugal compressor but do not involve its impact on the flow of the rotational-stationary disk cavity. By establishing a coupling model of the centrifugal compressor and the ribbed rotational-stationary disk cavity, the flow characteristics of the ribbed rotational-stationary disk cavity and the effect of the complex flow in the cavity on the axial force were studied. The ribbed rotational-stationary disk cavity is in line with the basic flow structure and characteristics of the Batchelor flow pattern, as demonstrated by the results. The radial balance equation derived based on this flow pattern is suitable for describing the radial motion of the fluid in the ribbed cavity; the rib can increase the tangential velocity in the rotating core center and elevate the proportion of core center in the cavity while weakening the effect of the boundary layer in the region close the rotational disk, which increases the swirl ratio in the cavity; based on the radial balance equation, the mechanism of radial ribs on reducing the axial force was proposed from the perspective of complex flow. The mechanism is as follows: By increasing the swirl ratio, the ribs cause the radial pressure gradient in the cavity to increase, and the average pressure acting on the rotational disk surface is reduced, which leads to a reduction in axial force.

Use of Electrocautery to Facilitate Suture Passage Through the Greater Trochanter of the Femur: A Biomechanical Study.

The specific aims of this study were to evaluate (1) the axial force reduction of suture passage utilizing electrocautery when applied to the greater trochanter of the femur, (2) the temperature change caused while using electrocautery for suture passage, and (3) the failure loads and failure modes utilizing this technique. Five matched pairs of fresh-frozen femurs were used and classified into two groups: with electrocautery on needle (study group) and without electrocautery on needle (control group). Two bicortical, osseous tunnels were made around the insertion of the gluteus medius tendon. Each specimen was sequentially tested in a needle penetration test and a single load-to-failure test. A #5 Ethibond suture with a straight needle was used. Electrocautery reduced the peak axial force for bone penetration in 40% (near cortex) and 70% (far cortex) of the trials, and no significant difference was detected between groups or between two osseous tunnels. The average peak force was significantly higher for the far cortex for both groups and for both osseous tunnels compared to the near cortex. There was no significant change in temperature of the tunnel site with electrocautery. Ninety percent of the samples experienced bone tunnel failure for the study group compared to 70% in the control group. The average ultimate failure load for the study group was lower compared with the control group, but this finding was not statistically significant (range: 6%-15%). Suture passage using electrocautery may not significantly decrease the peak force needed to pass a needle directly through the greater trochanter.

Use of electrocautery devices for suture passage through the greater tuberosity: a biomechanical study.

The use of electrocautery to facilitate passage of a suture needle through bone without the aid of a drill or burr is a novel technique that has potential utility in orthopedic procedures, but there is a scarcity of research to support its utility. The specific aims of this cadaveric biomechanical study were to evaluate (1) the axial force reduction during suture passage using electrocautery when applied to rotator cuff repair, (2) the temperature change caused while using electrocautery, and (3) the failure loads and failure modes of this technique. Five matched pairs of fresh frozen humeri were used, classified into 2 groups: with electrocautery on needle (study group) and without electrocautery on needle (control group). Four individual osseous tunnels were made on the greater tuberosity around the insertion of the supraspinatus tendon. Each specimen was sequentially tested in 2 parts: a needle penetration test (part I) to measure the peak axial force and temperature change and a single load-to-failure test (part II) to measure the maximum load to failure as well as the mechanism of failure. A No. 2 FiberWire suture with a straight needle was used. In part I, the mean peak axial force was lower in the study group compared with the control group for all osseous tunnels but was not statistically significant for individual tunnels. However, there was a significant decrease in peak axial force in the study group of 36% compared with the control group overall (P=.033). There was no significant change in temperature of the tunnel site with the use of electrocautery (mean: 0.2±0.3°C, P=.435). In part II, 100% of the samples from each study group experienced bone tunnel failure. Forty percent of the trials in the study group found lower ultimate failure loads compared with the control group (reduction range: 7%-38%). There was no statistically significant difference in the ultimate failure load between either the loop tested or between the 2 study groups (loop 1: P=.352; loop 2: P=.270). Suture passage using electrocautery does significantly decrease the peak force needed to pass a needle directly through the greater tuberosity. This technique does not appear to burn the bone or weaken the bone tunnels. This technique may be useful during open rotator cuff repair or shoulder arthroplasty, although clinicians should be cautious when using this technique as its utility depends on bone quality and cortical thickness, and invivo results may differ.

Characterization of Deformation of Bolts and Induced Stress Wave Propagation under Axial Tensile Stress

The nondestructive testing technique used to evaluate the quality of bolt support by detecting the axial force is suitable for the bolt with a short construction time. For the bolt in the support state for a long time period, it may lead to the detection of small axial force only and ignore the fact that the bolt has entered the necking fracture stage, and thus fail to detect safety hazards in time. Three sets of parallel tests were conducted to solve the misjudgment of detection results due to the reduction of axial force when the bolt was in the necking fracture stage. Bolt deformation characteristics and stress wave propagation characteristics in bolts under axial tensile stress were studied by using the bolt tensile and stress wave detection test system which was modified and built independently. The results showed that (1) The diameter of the necking position decreases continuously during the tensioning process of the bolt and the rate of decrease increases abruptly during the necking fracture stage. (2) Due to the bolt stretching, the stress wave propagates in the bolt with different degrees of reflection and transmission, resulting in the attenuation of the stress wave energy; the energy attenuation ratio of the stress wave signal in the necking fracture stage reaches 35%, and the energy attenuation ratio increases exponentially as the necking continues to occur. (3) The frequency distribution of the stress wave signal during the bolt stretching process is from scattered to concentrated, the dominant frequency is gradually prominent and changes from low frequency to high frequency, the high-frequency signal is more sensitive to the cracks and necking of the bolt, and the dominant frequency is between 9500 and 10,000 Hz. (4) The average error of the stress wave method is 1.945% and the maximum and minimum values are 4.12% and 0.51%, respectively. The method is promising and provides a reference for the study of nondestructive testing of bolt stress waves in field support.

The designing and modeling of equal base circle herringbone curved bevel gears

Based on the theory of equal base circle bevel gears, a new type of gear, the equal base circle herringbone curved bevel gear, is studied further to reduce the axial force problem of curved bevel gears. Using the principle of equal basis circle herringbone curved bevel gear as a basis, the tooth trace and the tool design of this gear were studied. Based on the principle of space meshing, the process of finger milling cutter enveloping machining gear was analyzed, and a tooth surface equation was calculated; This paper proposes two modeling methods: tooth trace modeling and tooth surface modeling. The gear model is consistent through the analysis and comparison of the two modeling methods. The axial force of the gear contact between the equal base circle herringbone curved bevel gear and Gleason are analyzed and compared, which verified the proper reduction of axial force.

Investigation of the self-balance impeller of a canned motor pump for axial force reduction

Canned motor pump is widely used in the transportation of chemical industry. The common failure component of the pump is the sliding bearing. The service life of the bearing will be directly reduced if it bears too much axial force. Thus, it has higher requirements on the axial force balance of the impeller. In this study, the axial force and the axial force self-balance position of the canned motor pump impeller were calculated and analyzed by numerical calculation and experimental verification. By deducing the theoretical formula of the clearance, the relationship between the total axial force of the impeller and the size of the axial clearance is obtained, which can be concluded simply to a functional equation. Based on the principle of curve fitting, an iterative asymptotic strategy is proposed to solve the self-balance position. This method successfully avoids the problem that the axial clearance falls into “solving interval traps.” The results show that the axial force is sensitive to axial clearance at a special interval. The axial clearance size decreases with the flow rate increasing. This study is of great significance for solving the axial force balance state of impeller.

Analysis of Oil Distribution and Reduction of Axial Force due to Oil Supply in a Multi-Plate Clutch

Analysis of Oil Distribution and Reduction of Axial Force due to Oil Supply in a Multi-Plate Clutch

Quantitative study of the control of hypersonic aerodynamics using millisecond pulsed discharges

The experimental study of the high-speed aerodynamic control using pulsed discharges is a fundamental yet relatively unexplored issue. This is because the strong electromagnetic interference (EMI) caused by these discharges can affect the accuracy of conventional measurements. A quantitative knowledge of this issue can help to evaluate the aerodynamic control capabilities of pulsed discharges. Therefore, in this study, a fiber-optic balance based on a Fabry–Pérot sensor, which is not subject to EMI, was applied to the acquisition of aerodynamic data with pulsed discharges in a Mach-6 flow. The pulsed discharges were characterized by a long pulse width of around 1 ms and a low frequency of 100 Hz. There was notable variation in the axial force under these pulsed discharges, which indicates their effectiveness for shock manipulation. In the presence of a pulsed discharge, fast-response Schlieren imaging revealed both shock-attenuation and thermal-choking effects in the aerodynamic control. The balance data indicate that the rate of axial-force reduction increases linearly with discharge pulse energy, but it decreases parabolically with increasing angle of attack.

Criteria of Using Optimum Size Approach for Reduction of Axial Forces in Column in Multi Storied Building under Seismic Zone III

Abstract: In India, every industry has its own importance to make the country shift towards its future goal. The construction industry plays a very significant role with the introduction of high-rise structures that has been increasing regularly. Beside this, the structure should be strong enough that each element should be economic and strong. The criteria of using optimum size approach for reduction of axial forces in column in multi storied building under seismic zone is a new idea. It reduces the size of beams and columns at the different levels of the building. On other hand, the structural weight should be minimized when the self-weight of the same will be reduced and proved to be an economic structure. In this project a G+13 Storey structure is analyzed using six different cases named as AFR Case A to AFR Case F assumed to be situated in seismic Zone III. The plinth area is in use as 625 m2 and all the cases have compared with each parameter. The project concluded that efficient Case is AFR Case C on comparing 6 maximum axial force reduction cases that ultimately reduce the overall cost of the project. Keywords: Axial forces, Columns, Strength, Durability, Software Models, High-Rise Structures

Review on Axial Forces acting on Column Members of Multistoried Building

In India, construction plays a very important role with the introduction of high-rise structures that has been increasing gradually. Along with this, the structure should be strong enough that each element should be economic and strong. The Reduction of Axial forces in Columns in Multistory building using Optimum size change approach is a new idea. It reduces the size of columns at the different levels of the building to reduce its self-weight. On other hand, the structural weight should be minimized when the self-weight of the same will be reduced and proved to be an economic structure. Concluding this, it is necessary to prepare various software models to analyze the structure and get the results regarding reduction of axial forces without disturbing the strength and durability of structure.

Differential Throttling and Fluidic Thrust Vectoring in a Linear Aerospike

Aerospike nozzles represent an interesting solution for Single-Stage-To-Orbit or clustered launchers owing to their self-adapting capability, which can lead to better performance compared to classical nozzles. Furthermore, they can provide thrust vectoring in several ways. A simple solution consists of applying differential throttling when multiple combustion chambers are used. An alternative solution is represented by fluidic thrust vectoring, which requires the injection of a secondary flow from a slot. In this work, the flow field in a linear aerospike nozzle was investigated numerically and both differential throttling and fluidic thrust vectoring were studied. The flow field was predicted by solving the Reynolds-averaged Navier–Stokes equations. The thrust vectoring performance was evaluated in terms of side force generation and axial force reduction. The effectiveness of fluidic thrust vectoring was investigated by changing the mass flow rate of secondary flow and injection location. The results show that the response of the system can be non-monotone with respect to the mass flow rate of the secondary injection. In contrast, differential throttling provides a linear behaviour but it can only be applied to configurations with multiple combustion chambers. Finally, the effects of different plug truncation levels are discussed.

Ultrasonic-assisted friction drilling process of aerospace aluminum alloy (AA7075): FEA and experimental study

Joining sheets and plates in the industry is of high importance. In the automotive and aerospace industry, using friction drilling technique is developing. In order to improve this method, different techniques have been used. In this research, applying ultrasonic vibration on the tool will be investigated. In this regard, a special tool was designed. Axial force and surface hardness were measured in friction drilling and ultrasonic assisted friction drilling. Higher rotational speed and lower feed rate induce lower axial force and higher surface hardness. In addition, ultrasonic vibration causes the surface to be harder with lower axial force. The results show that increasing the rotational speed and decreasing the feed rate in lathe machine causes axial force reduction and surface hardness increase in heat affect zone and thermomechanical region. Moreover, finite element method was carried out which indicated lower axial force occurs in ultrasonic assisted friction drilling comparing to conventional condition. Equivalent plastic strain was used to examine hardness value numerically. The obtained numerical and experiment results were in good agreement.

Study on the Influence of Reinforcement on Creep and Shrinkage Effects of Composite Beams

To obtain time-dependent behaviours of composite beams, the system of differential equations is established by Rüsch constitutive equation of creep. Rigorous solutions of the system are obtained by computer programs of the authors. Creep and shrinkage effects involve internal force redistribution and deflection increase, and these are significantly large for composite beam. Parameter analyse of the reinforcement of concrete slab on these effects is conducted. Among them the reinforcement aggravates significantly the reduction of axial force between individual sections and alliviates slightly the increase of deflection of the beam.

The effect of balancing holes on performance of a centrifugal pump: numerical and experimental investigations

In the present work, the effect of balancing hole’s diameter on the performance of a centrifugal pump is experimentally and numerically investigated. Normally, in centrifugal pumps, design of impeller and volute is carried out in such a way that pressure distribution on both sides of the impeller becomes similar, thus minimizing the axial force exerted on the pump impeller and bearings. However, in reality this goal is not totally fulfilled and due to design and manufacturing circumstances and limitations, significant axial forces are generated. As a result excessive load on bearings, noise, vibration and damage to pump performance are experienced. In order to reduce the axial force, several methods are proposed. The simplest method is drilling balancing holes on the impeller eye. In this study, numerical and experimental investigations have been conducted to study the effect of balancing holes on a centrifugal pump performance and axial force reduction. A test rig is designed and equipped with measuring instruments. Experimental data for pump performance including flow, head, power and efficiency were obtained. Next, numerical results were validated against experimental data and a good agreement was observed. It was found that increasing balancing holes diameter up to 5 mm can lead to 5.6% reduction in head at design point. Furthermore, it was found that the diameter of balancing hole affects the pump efficiency and can reduce it by 2.6%. Numerical investigation showed that the diameter of balancing hole can play a prominent role on the axial force reducing it significantly. Extreme care must be taken in selecting the diameter of balancing holes since increasing holes diameter beyond a specific value does not reduce the axial force significantly, but, still aggravates the pump performance undesirably. Therefore, an optimum diameter of 3.5 mm was selected whereby the axial force is reduced up 56% at design point while reduction in performance characteristics are acceptable.

Mechanism analysis of friction reduction in coiled tubing drilling with axial vibratory tool

In order to investigate the friction reduction mechanism of the hydraulic axial vibratory tool in coiled tubing drilling (CTD), a dynamic model is proposed by introducing the Coulomb friction term to the wave equations in this paper. Then a retrogressed case is selected to validate the model and both the results of two models display an excellent consistency. Finally, the effect of tool parameters (frequency, average drag force, installation position), CT parameters (size, rate of penetration) and wellbore parameters (coefficient of friction, wellbore curvature) on the tool performance are analyzed with the proposed model. The results indicate that the axial force reduction at the vertical end is mainly affected by the frequency, amplitude, installation position and coefficient of friction (CoF), whereas the CT size, rate of penetration (ROP) and wellbore curvature affect the tool performance slightly. Based on the study, it reveals the action mechanism of the tool in CTD that the force reduction mainly caused by the direct traction of the tool and the corresponding friction reduction at the curved and buckling section.

Experimental study of continuous-bending-under-tension of AA6022-T4

This paper presents an experimental setup for continuous-bending-under-tension (CBT) of thin strips and sheets, aimed at the investigation of the observed elongation-to-fracture (ETF) enhancements under such conditions. In particular, the kinematics of the process are described and correlated with the evolution of axial force measured during testing. The main results of the effect of process parameters, such as crosshead velocity and bending depth, on the ETF and the reduction of axial force are presented for the aluminum alloy AA6022-T4. The force vs. displacement response is not found to be a strong function of the crosshead velocity, which is explained by the near rate-independence of the material in the strain-rate range that occurs in CBT. Similarly, ETF does not show a clear dependence on the bending depth or the crosshead velocity. On the other hand, the axial force decreases linearly with the bending depth and slightly increases with the velocity. From the detailed analysis, the optimal parameters for enhancing ductility of AA6022-T4 under CBT are 1.2 mm/s for crosshead velocity and 2.0 for normalized bending depth. Under these conditions, a significant finding is that the strain level achieved throughout the CBT specimen is comparable to that in the necked region of a specimen tested to rupture in uniaxial tension.

Mechanism for material removal in ultrasonic vibration helical milling of Ti 6Al 4V alloy

Abstract High quality hole-making technology in the aviation industry is urgently needed due to the application of difficult-to-cut materials, such as titanium alloy, composite materials and the stacks in aircraft fuselage skins. To improve the hole-making quality, an ultrasonic vibration helical milling (UVHM) technology was developed for machining of Ti 6Al 4V alloy, meanwhile, comparison experiments were conducted between UVHM and conventional helical milling (HM) processes. Material removal mechanism of UVHM was investigated by modeling of cutting trajectories and the analysis of tool-workpiece contact behavior for bottom and peripheral cutting edges. The actual vibration frequency in UVHM was also determined by a theoretical-experimental combined method. Due to the vibration in UVHM, the bottom cutting edges generate discontinuous contact with workpiece. Unit forces considering material removal were modeled and applied to analyze the axial force reduction. The axial cutting forces of UVHM were reduced by 38–64% compared with HM at different cutting speeds. The cutting speed of peripheral cutting edge changes periodically. The cutting edges can separate with chips due to axial vibration, which will contribute to reducing the cutting forces and improving heat dissipation. Meanwhile, a friction effect was generated by the peripheral cutting edge which can improve the micro-scale surface roughness. Due to the effects of periodical friction and compression by ultrasonic vibration, UVHM increases the surface compressive stresses by 85% and 99% at the hole surface for axial and circumferential directions, respectively.

Design of IPMSM Applying V-Shape Skew Considering Axial Force Distribution and Performance Characteristics According to the Rotating Direction

Skew is a common method to reduce torque ripple and cogging torque. However, when skew is applied, unexpected axial force is produced. To reduce axial force, V-skew is used as one of the solutions. Specifically, when V-skew is applied, the magnetic flux distribution changes according to the rotating direction, which causes a difference in the performance. For the application in which the motor rotates in one direction, this phenomenon can be used to produce power with better quality torque and less losses. In this paper, the interior permanent-magnet synchronous motor (IPMSM) is designed by applying a V-skew to the stator, taking into consideration the manufacturing difficulties with applying a rotor skew to the IPMSM. The skew effect and the reduction of axial force are verified based on finite-element analysis. Moreover, torque, axial force, and losses are comparatively analyzed according to the rotating direction. All calculations and analysis are conducted based on 2-D and 3-D finite-element analysis.