scholarly journals Wear analysis of finger locks with different design parameters for landing gear

2020 ◽  
Vol 103 (3) ◽  
pp. 003685042095012
Author(s):  
Yu Hou ◽  
Ming Zhang ◽  
Hong Nie
Keyword(s):  
Axial Force ◽  
Landing Gear ◽  
Transition Phase ◽  
Design Parameters ◽  
Wear Analysis ◽  
Lock In

The finger lock in the retractable actuator of the landing gear will wear during repeated unlocking and locking. Therefore, the effects of six parameters including the material of the finger lock, the length of the finger lock, the diameter of the finger lock, the number of petals, and the angle of the fingertip on the unlocking force after 500 unlocking cycles are researched. Archard wear theory was performed to obtain the unlocking force after wear and the influence of six key parameters on the unlocking force in this paper. Then, wear experiment was designed and the effectiveness of model and the influence of six parameters were verified. The results show that the chamfers of the finger lock was most worn, causing the value of the axial unlocking force during the transition phase to increase, but it has little effect on the maximum unlocking axial force. The material of the lock has little effect on the axial force; the length, diameter and the number of petals are inversely proportional to the axial force, and the angle of the fingertip is proportional to the axial force. Using Archard method can effectively calculate the finger pattern wear of locks.

Numerical Investigation of the Effect of Balancing-Hole on the Axial Force of a Partial Emission Pump

2014 ◽  
Author(s):  
Zhang Lisheng ◽  
Jiang Jin ◽  
Xiao Zhihuai ◽  
Li Yanhui
Keyword(s):  
Axial Force ◽  
Stokes Equations ◽  
Dominant Role ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Design Parameters ◽  
Navier Stokes Equations ◽  
Computational Fluid Dynamics Cfd ◽  
The Cost

In this paper numerical simulations were conducted to analyze the effects of design parameters and distribution of balancing-hole on the axial-force of a partial emission pump. The studied pump is a single stage pump with a Barske style impeller. Based on the original impeller, we designed 7 pumps with different balancing-hole diameters and the partial emission pump equipped with different impellers were simulated employing the commercial computational fluid dynamics (CFD) software Fluent 12.1 to solve the Navier-Stokes equations for three-dimensional steady flow. A sensitivity analysis of the numerical model was performed with the purpose of balancing the contradiction of numerical accuracy and the cost of calculation. The results showed that, with increasing of the capacity, the axial force varies little. The diameter of the inner balancing-hole plays a dominant role of reducing axial-force of partial emission pump, the axial-force decreases with increasing of inner balancing-hole diameter on the whole range of operation, the axial-force of impeller without inner balancing-hole is approximately 3 times larger than that of impeller with inner balancing-hole. While the diameter of outer balancing-hole has a reverse effects compared with that of inner balancing-hole. With increasing of outer balancing-hole, the axial force increases accordingly.

Extrusion Modeling of Solid Plug Flow of Co-Rotating Twin Screw Pulping Extruder

2010 ◽  
Vol 97-101 ◽  
pp. 240-244 ◽  
Author(s):  
Xiao Yang Shen ◽  
Ping Wang ◽  
Shao Gang Liu
Keyword(s):  
Power Consumption ◽  
Axial Force ◽  
Flow Rate ◽  
Plug Flow ◽  
Solid Material ◽  
Design Parameters ◽  
Static Balance ◽  
Balance Principle ◽  
Twin Screw ◽  
Important Design

In order to calculate important design parameters, screw axial force and power consumption of twin screw pulping extruder (TSPE), considering actions of the solid material plug in reverse thread of the TSPE and according to static balance principle, an extrusion model including plug flowing and shearing in reverse thread is proposed in the paper. Based on the model, screw axial force, screw torque, power consumption and flow rate can be derived. When changing thread lead numbers or slot width on the flight of the reverse thread, theoretical calculating results and testing results are better consistent.

scholarly journals Analysis of Sensitive Parameters Affecting Unlocking Force of Finger Lock in Landing Gear

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Yu Hou ◽  
Ming Zhang ◽  
Hong Nie
Keyword(s):  
Mechanical Characteristics ◽  
Landing Gear ◽  
Effective Coefficient ◽  
Wear Model ◽  
Obvious Effect ◽  
Working Cycle ◽  
Inner Surface ◽  
Surface Diameter ◽  
Lock In ◽  
Sensitive Parameters

The mechanical characteristics of the unlocking force of the landing gear finger lock were studied in this paper, the influence of its diameter, fingertip angle, wear, and other factors on the unlocking force in one complete working cycle was analyzed, and the sensitive parameters that affect the unlocking force were obtained. Firstly, the unlocking force and wear of finger lock were calculated theoretically, and the changing rule of the unlocking force and wear with each parameter was obtained. Then, the validity of the correlation coefficient and model was verified by experiment. Finally, combined with the effective coefficient obtained from the experiment, the Archard wear model was used to simulate the change rule of lock force. The results show that in one complete working cycle, the inner surface diameter is negatively related to the unlocking force, fingertip diameter has little effect on the unlocking force, fingertip angle is negatively related to the unlocking force, and wear is positively related to the unlocking force; friction coefficient and fingertip angle are high sensitive parameters that affect the unlocking force, which have obvious effect on the unlocking force. The inner surface diameter, fingertip diameter of finger lock, and wear are the low sensitive parameters that affect the unlocking force, and the influence on the unlocking force is weak.

Development of Analytical Model of Cantilever Hook Performance

2005 ◽  
Vol 128 (2) ◽  
pp. 479-493 ◽  
Author(s):  
Gaurav Suri ◽  
Anthony F. Luscher
Keyword(s):  
Analytical Model ◽  
Axial Force ◽  
Polymeric Materials ◽  
Equation System ◽  
Contact Forces ◽  
Design Parameters ◽  
Future Research ◽  
Research Activity ◽  
Analytical Design ◽  
Input Design

With an increase in the use of polymeric materials in commercial products, snap-fits are attracting increased attention as alternatives to other, more traditional, joining methods. The field of snap-fit design is receiving greater attention as an engineering and research activity. Research in this area has focused on the development of performance models for individual features and heuristics for the design of snap-fit assemblies. An improved analytical model for cantilever hook snap-fit features is developed in this study. The modeling approach is a significant improvement over currently available analytical design equations. The model captures the effect of a snap-fit’s catch in causing contact forces to be offset from the beam’s neutral axis. Beam rotation, influence of axial force, and moment components on beam deformation are also incorporated by formulating a set of equations that model the system in its deformed configuration. The equation system is iteratively solved for several such configurations to model insertion and retention processes for snap-fits. The axial force component, which has been hitherto ignored in analytical design equations, is found to have significant effect on predicted snap-fit performance. The design space of cantilever hook features is explored by varying input design parameters. The model shows excellent agreement with experimental results, especially for low and medium retention angle snap-fit features. However, for high retention angle snap-fits, more accurate governing equations are required. Suggestions for possible improvements and future research directions are provided.

scholarly journals Impact of manufacturing errors of ball screw system on performance characteristics

2018 ◽  
Vol 224 ◽  
pp. 01042 ◽  
Author(s):  
Alexander Denisenko
Keyword(s):  
Axial Force ◽  
Metal Cutting ◽  
Translational Motion ◽  
Ball Screw ◽  
Independent Random Variables ◽  
Design Parameters ◽  
Axial Stiffness ◽  
Probabilistic Distribution ◽  
Manufacturing Errors ◽  
Calculation Results

To convert rotary motion into translational motion in modern metal-cutting machine tools, screw-nut rolling transmissions are widely used. Special requirements are placed on the stability of the operational characteristics of the screw-nut rolling transmission. The influence of the accuracy of manufacturing screw-nut transmission on the main transmission characteristics: axial stiffness and the moment of idling is considered. When analyzing the quality of the manufacture of the transmission, the following manufacturing errors were taken into account: the pitch errors of the screw and nut threads; errors in thread diameter of screw and nut; deviation of the thread profile of the screw and nut; the error of the diameter of the ball. Since these errors are independent random variables, on the basis of the basic propositions of the theory of probability, analytical dependencies were obtained to determine the coefficients connecting the variances of the design parameters and the variance of the probabilistic distribution of the axial force and the idling torque. Based on the calculation results from the obtained dependencies, it was concluded that the errors in the thread pitch of the screw and nut have a prevailing influence on the dispersion of the probabilistic distribution of the axial force (and, consequently, the axial stiffness) and the idling torque. The results obtained allow us to outline further ways of improving the transmission of the screw-nut rolling.

scholarly journals Influence of Rotational Stiffness Modeling on the Joint Behavior of Quasi-Rectangular Shield Tunnel Linings

2020 ◽  
Vol 10 (23) ◽  
pp. 8396 ◽  
Author(s):  
Weixi Zhang ◽  
Wouter De Corte ◽  
Xian Liu ◽  
Luc Taerwe
Keyword(s):  
Axial Force ◽  
Calculation Method ◽  
Bending Moment ◽  
Design Parameters ◽  
Shield Tunnel ◽  
Rotational Stiffness ◽  
Circular Tunnel ◽  
Constant Stiffness ◽  
Specific Geometry ◽  
Nonlinear Deformations

A beam-spring model with constant rotational stiffness is a practical tool for the prediction of the general deformations and bending moments in circular tunnel linings. However, in reality, the rotational stiffness of a segmental joint is not constant, due to nonlinear deformations and local yielding in the vicinity of the joint. These are a result of the specific geometry at the joint, which is related to water-tightness measures and buildability issues. For quasi-rectangular tunnels this nonlinearity should not be neglected, as the bending component in the lining is significantly larger compared to circular linings. To date, there are only few studies that have investigated a calculation method for consideration of the joint’s nonlinear moment-axial force and shear-axial force interaction behavior and its consequences on the calculated lining behavior. In this paper, an iterative incremental method is proposed to tackle this issue, based on rotational stiffness curves derived from 3D nonlinear finite element modelling of the joints, and substantiated by testing. The significance of the variable rotational stiffness is highlighted through a comparison with results based on a constant stiffness assumption. Further, using the proposed calculation method, the effects of the circumferential joints, the bending moment transmission and several other parameters on the full-ring behavior of quasi-rectangular tunnels are discussed for a wide interval of design parameters. The results provide some new insights into the behavior of this non-traditional tunnel type. Although the presented results are related to specific overall and local geometries, the presented method is considered to be useful for the design of other special tunnel geometries.

scholarly journals Selection of rational parameters of the cone roller for deep compaction of road bases

2021 ◽  
Vol 7 (1) ◽  
pp. 82-89
Author(s):  
K.Z. Tilloev ◽  
◽  
E.I. Kromsky ◽  
S.V. Kondakov ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Axial Force ◽  
Cone Angle ◽  
Original Method ◽  
Frozen Soil ◽  
Design Parameters ◽  
Total Force ◽  
Cost Criterion ◽  
Optimal Value ◽  
The Mathematical Model

The article is devoted to the method of designing a cone roller for deep compaction of soil used as the working body of a crawler excavator. One of the most important design parameters of a cone roll is the angle of the cone. Known methods allow determining the cone angle for other technological tasks, for example, for loosening frozen soil, and cannot be directly applied to solve the problem. The authors propose an original method for selecting rational parameters of a cone roller head, including the angle of the cone. The method uses a mathematical model of the interaction of a cone roller with compacted soil. In the process of solving the mathematical model are the following parameters: the dependence of the area of the lateral surface of a cone, the dependence of the volume of displaced soil on the contact surface of the cone from the contact patch, the total force, cone force acting on the ground torsional, and axial force in the implementation of the cone, applied by the excavator boom. To identify the optimal value of the cone angle, the function of the volume of displaced soil from the cone angle and the axial force during penetration from the cone angle was studied. As a result, it is determined that the optimal angle of the cone is 240, which will provide the greatest efficiency according to the performance / cost criterion.

Effects of magnetic core parameters on landing stability and efficiency of magnetorheological damper-based landing gear system

2019 ◽  
Vol 31 (2) ◽  
pp. 198-208 ◽  
Author(s):  
Chulhee Han ◽  
Bo-Gyu Kim ◽  
Byung-Hyuk Kang ◽  
Seung-Bok Choi
Keyword(s):  
Equations Of Motion ◽  
Magnetic Core ◽  
Landing Gear ◽  
Gear System ◽  
Magnetorheological Damper ◽  
Design Parameters ◽  
Damping Force ◽  
Magnetic Circuits ◽  
Aircraft Landing ◽  
New Type

In this research, a new type of magnetorheological damper for a small-sized aircraft landing gear system is proposed and its performance is evaluated with respect to design parameters of the magnetic core. As a first step, a new configuration of magnetorheological damper for the landing gear system, which consists of orifices, recoil valve, and magnetic circuits, is introduced with working principles. After formulating the governing equations of motion, six different models of magnetorheological damper featuring different number of magnetic core and different pole length are chosen to investigate both the landing stability and the efficiency. Subsequently, the distribution of the magnetic field intensity of each model is analyzed through the finite element method, followed by the calculation of the field-dependent damping force to be used for the landing simulation, which is undertaken by adopting the dynamic model of a half airplane landing gear system. In order to identify the significance of the magnetic core parameters, the landing stability is judged from the sign of the minimum force and the landing efficiency is determined from the energy dissipation during the vertical drop motion.

Passive Regulation of Thermally Induced Axial Force and Displacement in Microbridge Structures

2017 ◽  
Vol 84 (12) ◽  
Author(s):  
Pezhman Hassanpour ◽  
Patricia M. Nieva ◽  
Amir Khajepour
Keyword(s):  
Analytical Model ◽  
Axial Force ◽  
Software Package ◽  
Coefficient Of Thermal Expansion ◽  
Thermomechanical Behavior ◽  
Design Parameters ◽  
Thermally Induced ◽  
Sensitivity Equations ◽  
Special Cases ◽  
Castigliano’S Theorem

The analytical model of a mechanism for regulating the thermally induced axial force and displacement in a fixed–fixed microbeam is presented in this article. The mechanism which consists of a set of parallel chevron beams replaces one of the fixed ends of the microbeam. The thermomechanical behavior of the system is modeled using Castigliano’s theorem. The effective coefficient of thermal expansion is used in the analytical model. The analytical model takes into account both the axial and bending deformations of the chevron beams. The model provides a closed-form equation to determine the thermally induced axial force and displacement in the microbeam. In addition, the model is used to derive the equations for the sensitivities of the microbeam’s axial force and displacement to the variations of the design parameters involved. Moreover, the model produces the stiffness of the chevron beams. The effect of the stiffness of the chevron beams on the dynamic behavior of the microbeam is discussed. The analytical model is verified by finite element modeling using a commercially available software package. Using the analytical model, two special cases are highlighted: a system with thermally insensitive axial force and a system with thermally insensitive axial displacement. The main application of the model presented in this article is in the design of sensors and resonators that require robustness against changes of temperature in the environment. The analytical model and the sensitivity equations can be easily integrated into optimization algorithms.

scholarly journals An Experimental and Numerical Study on Reduction of Generated Axial Force

2021 ◽  
Vol 11 (19) ◽  
pp. 8836
Author(s):  
Seong Han Kim ◽  
Do Hoon Kim ◽  
Gwang Hee Jo
Keyword(s):  
Contact Angle ◽  
Optimal Design ◽  
Axial Force ◽  
Significant Influence ◽  
Design Parameter ◽  
Constant Velocity ◽  
Numerical Study ◽  
Design Parameters ◽  
Constant Velocity Joint ◽  
Generated Axial Force

This paper proposes an experimental and numerical study to reduce the generated axial force (GAF) in a tripod constant velocity joint (CVJ). Based on the GAF model developed through kinematic and frictional analysis on the tripod CVJ, the key parameters that have a significant influence on the GAF are obtained. These parameters vary with the design parameters of the CVJ and the optimal design parameter with the lowest GAF are presented. The GAF of a tripod CVJ is estimated by the developed model, with respect to various design parameters, and the results shows that track curvature highly affects the GAF whereas contact angle hardly affects the GAF. The GAF decreases with the decrease of track curvature, and the minimum GAF occurs at −20% track curvature and +20% contact angle.

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