Thermal Analysis of a Ball-Screw System

2012 ◽  
Vol 591-593 ◽  
pp. 818-826 ◽  
Author(s):  
Chin Chung Wei ◽  
Jeng Haur Horng ◽  
Jen Fin Lin
Keyword(s):  
Finite Element ◽  
Thermal Expansion ◽  
Finite Element Model ◽  
High Speed ◽  
Element Model ◽  
Surface Strain ◽  
Ball Screw ◽  
Control Factor ◽  
Positioning Error ◽  
Positioning Control

High speed ball-screw system has serious friction heat to form thermal expansion to each component. An analyzing model considering with contact deformation and thermal expansion is established in realizing positioning error for a high speed ball-screw system. A finite element model of nut is also built in calculating elongation of nut. Surface strain of nut is measured by strain gages in order to confirm with data obtained from finite element model. Temperature of nut and screw were also measured by thermal couples and are used in calculation of elongation by the use of linear elongation equation. The tendency of positioning error is well estimated by the analyzing model. The model can be used in feedback positioning control factor and develop precision high speed ball-screw system.

Comparison of femur strain under different loading scenarios: Experimental testing

2020 ◽  
Vol 235 (1) ◽  
pp. 17-27
Author(s):  
Ievgen Levadnyi ◽  
Jan Awrejcewicz ◽  
Yan Zhang ◽  
Yaodong Gu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Strain Distribution ◽  
Element Model ◽  
Surface Strain ◽  
Image Correlation ◽  
Loading Conditions ◽  
Bone Implant ◽  
Bone Stiffness

Bone fracture, formation and adaptation are related to mechanical strains in bone. Assessing bone stiffness and strain distribution under different loading conditions may help predict diseases and improve surgical results by determining the best conditions for long-term functioning of bone-implant systems. In this study, an experimentally wide range of loading conditions (56) was used to cover the directional range spanned by the hip joint force. Loads for different stance configurations were applied to composite femurs and assessed in a material testing machine. The experimental analysis provides a better understanding of the influence of the bone inclination angle in the frontal and sagittal planes on strain distribution and stiffness. The results show that the surface strain magnitude and stiffness vary significantly under different loading conditions. For the axial compression, maximal bending is observed at the mid-shaft, and bone stiffness is also maximal. The increased inclination leads to decreased stiffness and increased magnitude of maximum strain at the distal end of the femur. For comparative analysis of results, a three-dimensional, finite element model of the femur was used. To validate the finite element model, strain gauges and digital image correlation system were employed. During validation of the model, regression analysis indicated robust agreement between the measured and predicted strains, with high correlation coefficient and low root-mean-square error of the estimate. The results of stiffnesses obtained from multi-loading conditions experiments were qualitatively compared with results obtained from a finite element analysis of the validated model of femur with the same multi-loading conditions. When the obtained numerical results are qualitatively compared with experimental ones, similarities can be noted. The developed finite element model of femur may be used as a promising tool to estimate proximal femur strength and identify the best conditions for long-term functioning of the bone-implant system in future study.

Simulation and Experimental Research on Milling Force of High Manganese Steel

2010 ◽  
Vol 143-144 ◽  
pp. 863-867
Author(s):  
Yong Tang ◽  
Qiang Wu ◽  
Xiao Fang Hu ◽  
Yu Zhong Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Speed ◽  
Shear Failure ◽  
Element Model ◽  
Manganese Steel ◽  
High Manganese ◽  
Milling Force ◽  
High Manganese Steel ◽  
High Speed Milling

The milling process of hard-to-cut material high manganese steel ZGMn13 was simulated and experimental studied based on Johnson-Cook material model and shear failure model.The high speed milling processing finite element model has established adopting arbitrary Lagrangian-Euler method (ALE) and the grid adaptive technology,The influence of milling parameters to milling force is analyzed in the high speed milling high manganese steel process. The simulated and experimental results being discussed are matched well. It certifies the finite element model is correct.

Validation of a New Finite Element Model for Human Knee Ligaments for Use in High Speed Automotive Collisions

2009 ◽  
Author(s):  
Chiara Silvestri ◽  
Louis R. Peck ◽  
Kristen L. Billiar ◽  
Malcolm H. Ray
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Strain Rate ◽  
High Speed ◽  
Element Model ◽  
Knee Ligament ◽  
Knee Ligaments ◽  
Human Knee ◽  
Dynamic Representation ◽  
Failure Properties

A finite element model of knee human ligaments was developed and validated to predict the injury potential of occupants in high speed frontal automotive collisions. Dynamic failure properties of ligaments were modeled to facilitate the development of more realistic dynamic representation of the human lower extremities when subjected to a high strain rate. Uniaxial impulsive impact loads were applied to porcine medial collateral ligament-bone complex with strain rates up to145 s−1. From test results, the failure load was found to depend on ligament geometric parameters and on the strain rate applied. The information obtained was then integrated into a finite element model of the knee ligaments with the potential to be used also for representation of ligaments in other regions of the human body. The model was then validated against knee ligament dynamic tolerance tests found in literature. Results obtained from finite element simulations during the validation process agreed with the outcomes reported by literature findings encouraging the use of this ligament model as a powerful and innovative tool to estimate ligament human response in high speed frontal automotive collisions.

The Analysis of Influence Factors about Dynamic Characteristics of a Ball Screw Feed Drive System

2015 ◽  
Vol 799-800 ◽  
pp. 576-580 ◽  
Author(s):  
Yi Guang Shi ◽  
Hui Xiao ◽  
Jun Ao Zhang ◽  
Da Wei Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Natural Frequency ◽  
Element Model ◽  
Drive System ◽  
Ball Screw ◽  
Feed Drive ◽  
Joint Parameters ◽  
Feed Drive System ◽  
Screw Feed

This paper presents relationships between some vital parameters and the natural frequency of the ball screw feed drive system. A finite element model (FEM) of a machine tool feed drive system is established with joint parameters added in based on the SAMCEF software. Using the finite element model, the influences of the material properties of the worktable, the diameter of the ball screw and joint parameters on the natural frequency of axial vibration are derived. These results provide a reliable basis for the optimization design of the ball screw feed drive system.

scholarly journals Simulation Analysis of a Multiple-Vehicle, High-Speed Train Collision Using a Simplified Model

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Suchao Xie ◽  
Weilin Yang ◽  
Ping Xu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Speed ◽  
Large Scale ◽  
Computing Time ◽  
Element Model ◽  
Vehicle Body ◽  
Railway Vehicle ◽  
Storage Space ◽  
High Speed Train

To solve the problems associated with multiple-vehicle simulations of railway vehicles including large scale modelling, long computing time, low analysis efficiency, need for high performance computing, and large storage space, the middle part of the train where no plastic deformation occurs in the vehicle body was simplified using mass and beam elements. Comparative analysis of the collisions between a single railway vehicle (including head and intermediate vehicles before, and after, simplification) and a rigid wall showed that variations in impact kinetic energy, internal energy, and impact force (after simplification) are consistent with those of the unsimplified model. Meanwhile, the finite element model of a whole high-speed train was assembled based on the simplified single-vehicle model. The numbers of nodes and elements in the simplified finite element model of the whole train were 63.4% and 61.6%, respectively, compared to those of the unsimplified model. The simplified whole train model using the above method was more accurate than the multibody model. In comparison to the full-size finite element model, it is more specific, had more rapid computational speed, and saved a large amount of computational power and storage space. Finally, the velocity and acceleration data for every car were discussed through the analysis of the collision between two simplified trains at various speeds.

Modal Analysis of BT Spindle-Toolholder Interface Based on Abaqus/Standard

2013 ◽  
Vol 662 ◽  
pp. 632-636
Author(s):  
Yong Sheng Zhao ◽  
Jing Yang ◽  
Xiao Lei Song ◽  
Zi Jun Qi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Element Model ◽  
Contact Theory ◽  
High Speed Machining ◽  
The Finite Element Model

The quality of high speed machining is directly related to dynamic characteristics of spindle-toolholder interface. The paper established normal and tangential interactions of BT spindle-toolholder interface based on finite element contact theory, and analysed free modal in Abaqus/Standard. Then the result was compared with the experimental modal analysis. It shows that the finite element model is effective and could be applied in the future dynamic study of high-speed spindle system.

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