Stiffness Modeling and Sensitivity Analysis for Worm Geared Transmission

2014 ◽  
Vol 989-994 ◽  
pp. 3328-3330
Author(s):  
Lin Han ◽  
Hou Jun Qi
Keyword(s):  
Sensitivity Analysis ◽  
Machine Tools ◽  
Torsional Stiffness ◽  
Axial Stiffness ◽  
Static Stiffness ◽  
Meshing Stiffness ◽  
Stiffness Modeling ◽  
Transmission Chain ◽  
Stiffness Model ◽  
Simulation Results

The worm geared transmission chain is widely employed in rotary feeding table of machine tools. This article proposes a static stiffness model and conducts sensitivity analysis of the transmission chain. Firstly, a unified static stiffness model is established, considering meshing stiffness, torsional stiffness and pre-load related axial stiffness of worm shaft. Then sensitivity with respect to individual stiffness element is derived based on partially differentiating method. Simulation results show that the closer to the end gear pair or shaft is, the more sensitive meshing stiffness or torsional stiffness is.

scholarly journals Static stiffness modeling and sensitivity analysis for geared system used for rotary feeding

2013 ◽  
Vol 228 (8) ◽  
pp. 1431-1443 ◽  
Author(s):  
Lin Han ◽  
Dawei Zhang ◽  
Yanling Tian ◽  
Fujun Wang ◽  
Hui Xiao
Keyword(s):  
Sensitivity Analysis ◽  
Transmission System ◽  
Torsional Stiffness ◽  
Design Parameters ◽  
Mechanical Transmission ◽  
Static Stiffness ◽  
Feed System ◽  
Stiffness Model ◽  
The Individual ◽  
Torsional Angles

The positioning accuracy of rotary feed system under load greatly depends on the static stiffness of mechanical transmission system. This paper proposes a unified static stiffness model of rotary feed system with geared transmission system. Taking the torsional stiffness of transmission shaft and mesh stiffness of gear pairs into account, the motion equations of the whole transmission system are presented. Based on the static equilibrium, a unified expression for the relationship between torsional angles of two adjacent elements is derived. Then a unified static stiffness model is presented. Furthermore, analytical expressions for sensitivity analysis of the static stiffness on the individual element’s stiffness and design parameters are derived. The presented model is verified by a traditional model, and a good agreement is obtained. The influence of phase angle of meshing gear pairs on the resultant static stiffness is investigated. An example transmission system is employed to perform the sensitivity analysis and the results are analyzed. The proposed model provides an essential tool for the design of rotary feed system satisfying requirement of static stiffness.

Analysis and Optimal Design for the Static Stiffness of a 2UPS-UPR Parallel Machine Tool

2009 ◽  
Vol 626-627 ◽  
pp. 429-434 ◽  
Author(s):  
Liang Zhao ◽  
Ya Dong Gong ◽  
Guang Qi Cai
Keyword(s):  
Machine Tool ◽  
Structural Design ◽  
Machine Tools ◽  
Structural Parameters ◽  
Parallel Machine ◽  
Static Stiffness ◽  
Stiffness Analysis ◽  
Stiffness Model ◽  
Parallel Machine Tool ◽  
Stiffness Distribution

The stiffness model of the parallel machine tool is established by static analysis, the static stiffness analysis is carried out through numerical Simulation and the stiffness distribution is given. On the basis of this, the optimal objective is given which is the average of 729 values of -axis stiffness and -axis stiffness corresponding to 729 positions in the workspace. With MATLAB software, the effects are simulated which the structural parameters of the parallel machine tool have on their stiffness, their change rules are gained, and this provides a basis for the structural design of this type of machine tools.

scholarly journals MODELING AND IDENTIFICATION OF BALL SCREW FEED DRIVE SYSTEMS

2020 ◽  
Vol 5 (8) ◽  
Author(s):  
M. A. Asy ◽  
S. A. Hassan ◽  
M. H Elsaroukh ◽  
M. H Elsaroukh
Keyword(s):  
Frequency Response ◽  
Dynamic Behavior ◽  
Machine Tools ◽  
Drive System ◽  
Torsional Stiffness ◽  
Ball Screw ◽  
Axial Stiffness ◽  
Feed Drive ◽  
Feed Drive System ◽  
Screw Feed

In this paper, the ball screw feed drive system is simulated and it?s frequency response is studied. Various parameters effect on the dynamic behavior of the ball screw system have been investigated. Ball screw feed drive system is used in high speed machine tools due to their high efficiency. Estimation of the dynamic behavior of ball screw feed drive mechanism is very important in the industrial processes in order to get high demand for precision and accuracy in machine tools. Optimizing the drive operation can provide significant cost savings. A four degree of freedom system, lumped parameter model is used for modeling a single axis ball screw feed drive system and use it to study and analyze vibrations in this model. The mathematical modeling provides an important information about frequency response when applying different levels of table mass, stiffness of the nut, axial stiffness of the ball screw shaft and torsional stiffness of the ball screw on the system, to describe the effects of these parameters on the system dynamic behavior. The study of dynamic response of ball screw feed drive system provides a better performance control and better understanding of ball screw dynamics.

A realistic model for transverse shear stiffness prediction of composite corrugated-core sandwich structure with bonding effect

2021 ◽  
pp. 109963622199386
Author(s):  
Tianshu Wang ◽  
Licheng Guo
Keyword(s):  
Present Model ◽  
Shear Stiffness ◽  
Realistic Model ◽  
Torsional Stiffness ◽  
Fem Model ◽  
The Core ◽  
Bonding Effect ◽  
Stiffness Model ◽  
Bonding Area ◽  
The Relationship

In this paper, a shear stiffness model for corrugated-core sandwich structures is proposed. The bonding area is discussed independently. The core is thought to be hinged on the skins with torsional stiffness. The analytical model was verified by FEM solution. Compared with the previous studies, the new model can predict the valley point of the shear stiffness at which the relationship between the shear stiffness and the angle of the core changes from negative correlation to positive correlation. The valley point increases when the core becomes stronger. For the structure with a angle of the core smaller than counterpart for the valley point, the existing analytical formulations may significantly underestimate the shear stiffness of the structure with strong skins. The results obtained by some previous models may be only 10 persent of that of the present model, which is supported by the FEM model.

Design, static analysis and development of a new three-legged shake table

2021 ◽  
pp. 095440622110184
Author(s):  
Ganesh Mangavu ◽  
Anjan Kumar Dash
Keyword(s):  
Vertical Motion ◽  
Torsional Stiffness ◽  
Shake Table ◽  
Lateral Motion ◽  
Sinusoidal Motion ◽  
Gravity Load ◽  
Simulation Results ◽  
Electromechanical Actuation ◽  
Translational Stiffness ◽  
Earthquake Data

In this paper, an alternative design is proposed based on a family of three-legged manipulators. Such manipulators have two actuators (one vertical and one horizontal) in each leg, unlike the standard UP̅S Stewart platform, which has one actuator in each leg. The arrangement of the two actuators is such a way that, to have vertical motion of the shake table only the Vertical Motion Actuators (VMA) are actuated and for longitudinal or lateral motion, the Horizontal Motion Actuators (HMA) alone are moved. Due to its inherent features such as simplified kinematics, control and distributed loading, a study is carried out to determine the performance of such three-legged manipulators as a shake table. Sinusoidal motion and white noise motions are given to the actuators and shown that the VMA forces have linear relationship with the platform forces. The translational stiffness and the torsional stiffness are studied separately for the manipulators. In the dynamic analysis, it is highlighted that the gravity load of the legs is borne by the Vertical actuators, irrespective of the motion being spatial or planar. Hence, this topology provides scope for lighter electromechanical actuation. The performance analysis of the 3 legged configuration is accomplished using simulation results, in comparison to a 7-UP̅S configuration of shake table. A prototype of the shake table is fabricated and tested with earthquake data of El Centro.

scholarly journals Numerical Simulation and Experimental Study on Axial Stiffness and Stress Deformation of the Braided Corrugated Hose

2021 ◽  
Vol 11 (10) ◽  
pp. 4709
Author(s):  
Dacheng Huang ◽  
Jianrun Zhang
Keyword(s):  
Numerical Simulation ◽  
Geometric Model ◽  
Equivalent Stress ◽  
Element Model ◽  
Maximum Error ◽  
Structural Features ◽  
Axial Stiffness ◽  
Frictional Stress ◽  
Maximum Equivalent Stress ◽  
Simulation Results

To explore the mechanical properties of the braided corrugated hose, the space curve parametric equation of the braided tube is deduced, specific to the structural features of the braided tube. On this basis, the equivalent braided tube model is proposed based on the same axial stiffness in order to improve the calculational efficiency. The geometric model and the Finite Element Model of the DN25 braided corrugated hose is established. The numerical simulation results are analyzed, and the distribution of the equivalent stress and frictional stress is discussed. The maximum equivalent stress of the braided corrugated hose occurs at the braided tube, with the value of 903MPa. The maximum equivalent stress of the bellows occurs at the area in contact with the braided tube, with the value of 314MPa. The maximum frictional stress between the bellows and the braided tube is 88.46MPa. The tensile experiment of the DN25 braided corrugated hose is performed. The simulation results are in good agreement with test data, with a maximum error of 9.4%, verifying the rationality of the model. The study is helpful to the research of the axial stiffness of the braided corrugated hose and provides the base for wear and life studies on the braided corrugated hose.

Experimental Analysis of Static Stiffness for Vehicle Body in White

2012 ◽  
Vol 248 ◽  
pp. 69-73 ◽  
Author(s):  
Shu Ming Chen ◽  
Xue Wei Song ◽  
Chuan Liang Shen ◽  
Deng Feng Wang ◽  
Wei Li
Keyword(s):  
Test Bench ◽  
Bending Stiffness ◽  
Torsional Stiffness ◽  
Vehicle Body ◽  
Torsional Angle ◽  
Static Stiffness ◽  
Torsional Deformation ◽  
Automotive Body ◽  
Body In White ◽  
Stiffness Characteristics

In order to know the static stiffness characteristics of the vehicle body in white, the bending stiffness and torsional stiffness of an automotive body in white were tested on a test bench of the static stiffness of an automotive BIW. The bending stiffness and bending deformation of the bottom of the BIW were determined. Also, the torsional stiffness and torsional deformation of the bottom of the BIW were obtained. The fitting curves and equations between loading torque and torsional angle were acquired at clockwise and counterclockwise loading, respectively.

A Proximally-Adjustable Variable Length Intramedullary Nail: Ex Vivo Quasi-Static and Cyclic Loading Evaluation

2017 ◽  
Vol 11 (4) ◽  
Author(s):  
Mark J. Hedgeland ◽  
Alexander Martin Clark ◽  
Mario J. Ciani ◽  
Arthur J. Michalek ◽  
Laurel Kuxhaus
Keyword(s):  
Cyclic Loading ◽  
Mechanical Performance ◽  
Ex Vivo ◽  
Healing Process ◽  
Axial Loading ◽  
Torsional Stiffness ◽  
Axial Stiffness ◽  
Four Point Bending ◽  
Point Bend ◽  
Static And Cyclic Loading

An adjustable-length intramedullary (IM) nail may reduce both complications secondary to fracture fixation and manufacturing costs. We hypothesized that our novel nail would have suitable mechanical performance. To test this hypothesis, we manufactured three prototypes and evaluated them in quasi-static axial compression and torsion and quasi-static four-point bending. Prototypes were dynamically evaluated in both cyclic axial loading and four-point bending and torsion-to-failure. The prototypes exceeded expectations; they were comparable in both quasi-static axial stiffness (1.41 ± 0.37 N/m in cervine tibiae and 2.30 ± 0.63 in cadaver tibiae) and torsional stiffness (1.05 ± 0.26 N·m/deg in cervine tibiae) to currently used nails. The quasi-static four-point bending stiffness was 80.11 ± 09.360, greater than reported for currently used nails. A length-variance analysis indicates that moderate changes in length do not unacceptably alter bone-implant axial stiffness. After 103,000 cycles of axial loading, the prototype failed at the locking screws, comparable to locking screw failures seen clinically. The prototypes survived 1,000,000 cycles of four-point bend cyclic loading, as indicated by a consistent phase angle throughout cyclic loading. The torsion-to-failure test suggests that the prototype has adequate resistance to applied torques that might occur during the healing process. Together, these results suggest that our novel IM nail performs sufficiently well to merit further development. If brought to market, this adjustable-length IM nail could reduce both patient complications and healthcare costs.

scholarly journals Sensitivity Analysis of the Transmission Chain of a Horizontal Machining Tool Axis to Design and Control Parameters

2014 ◽  
Vol 6 ◽  
pp. 169064 ◽  
Author(s):  
Stefano Mauro ◽  
Stefano Pastorelli ◽  
Tharek Mohtar
Keyword(s):  
Sensitivity Analysis ◽  
Lumped Parameter Model ◽  
Control Parameters ◽  
Damping Coefficients ◽  
Transmission Chain ◽  
Lumped Parameter ◽  
Tool Axis ◽  
Optimal Value ◽  
Structural Parts ◽  
And Control

This paper reports how a numerical controlled machine axis was studied through a lumped parameter model. Firstly, a linear model was derived in order to apply a modal analysis, which estimated the first mechanical frequency of the system as well as its damping coefficients. Subsequently, a nonlinear system was developed by adding friction through experimentation. Results were validated through the comparison with a commercial servoaxis equipped with a Siemens controller. The model was then used to evaluate the effect of the stiffness of the structural parts of the axis on its first natural frequency. It was further used to analyse precision, energy consumption, and axis promptness. Finally a cost function was generated in order to find an optimal value for the main proportional gain of the position loop.

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