scholarly journals A novel identification technique of machine tool support stiffness under the variance of structural weight

2021 ◽  
Author(s):  
Zhen-Wei Zhuang ◽  
Jen-Chang Lu ◽  
De-Shin Liu
Keyword(s):  
Finite Element ◽  
Machine Tool ◽  
Modal Analysis ◽  
Reaction Force ◽  
Maximum Error ◽  
Impact Testing ◽  
Tool Support ◽  
Analysis Model ◽  
Modal Assurance Criterion ◽  
Element Analysis

AbstractThe preload-dependent stiffness of machine tool support was investigated in this study. A novel identification method of support stiffness has been proposed through the experimental modal analysis and finite element method. The support stiffness was identified with different machine weight during the assembling process of a machining center. Specifically, the structure weight increase of a machine tool in the assembly process causes its center of gravity to shift. Accordingly, the variance of support reaction affects the support stiffness. To explore the variance of support stiffness, the researchers of this study collaborated with a machine tool manufacturer. Impact testing was performed on each assembly stage. Additionally, finite element analysis was used to establish equations between the reaction force versus stiffness of supports under the structural weight variance. The obtained equations were used to predict the natural frequency and vibration mode of structures in various assembly stages. The maximum error between the experimental and simulated natural frequencies was 7.1%, and the minimum modal assurance criterion was 0.77. Finally, a modal analysis model that updates support stiffness automatically, which could be adopted by machine builders to develop new machine tool, is proposed.

Thermal Characteristics Finite Element Analysis and Temperature Rise Experiment for High Speed Motorized Spindle

2011 ◽  
Vol 52-54 ◽  
pp. 1206-1211 ◽  
Author(s):  
Huai Xing Wen ◽  
Mei Yan Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Machine Tool ◽  
Temperature Rise ◽  
High Speed ◽  
Thermal Characteristics ◽  
Analysis Model ◽  
Ansys Software ◽  
Motorized Spindle ◽  
Element Analysis

The thermal characteristics of the motorized spindle determines maching qualities and cutting capabilities, and is one of the important factors influencing the precision of the high speed NC machine tool. To improve the performance of the high speed machine tool, it is important to study the thermal characteristics of the motorized spindle. It had been studied in two ways: one is finite element analysis by Ansys software, in which the finite element analysis model was built. According to the actual working condition, the heat source and the heat transfer coefficient of every part are calculated. On this basis, the temperature field and temperature rises were gotten in Ansys software. The other way is temperature rises experiment on the motorized spindle test platform. The result was shown in the form of curve. These two ways shown the same result: the highest temperature rise appears in the area of electromotor, then followed by the rolling bearing .The result provides the necessary theory basis for optimizing the structure of the motorized spindle and establishes a basis for the research and application about the high speed spindle.

Structural Strength and Modal Analysis of a Certain Type of Heavy Vehicle Frame

2015 ◽  
Vol 757 ◽  
pp. 69-73 ◽  
Author(s):  
Zhi Qing Guo ◽  
Yan Jiao Li ◽  
Chang Jiang Liu ◽  
Qiu Juan Lv ◽  
Zhong Bao Qin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Modal Analysis ◽  
Computer Aided Design ◽  
Heavy Vehicle ◽  
Analysis Model ◽  
Element Analysis ◽  
Advantages And Disadvantages ◽  
Structure Reliability ◽  
Aided Design

This article make a research based on a certain type of heavy vehicle, In the research, we have made some analyses on structure reliability of the heavy truck with the assistance of some simulation platforms, such as computer aided design, finite element analysis, etc.. Based on the establishment of a correct finite element analysis model, analysis method is mainly about some research of the frame, such as typical working conditions of static analysis and modal analysis. Through these work, we can have a better understanding about the static and dynamic characteristic of the frame, so that we can find out the advantages and disadvantages of the car.

Modeling and experimental verification on directivity of an electret cell array loudspeaker

2012 ◽  
Vol 24 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Yu-Chi Chen ◽  
Wen-Ching Ko ◽  
Han-Lung Chen ◽  
Hsu-Ching Liao ◽  
Wen-Jong Wu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Digital Control System ◽  
Analysis Model ◽  
Cell Array ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
The Finite Element Analysis ◽  
Directivity Characteristics

We propose a model to give us a method to investigate the characteristic three-dimensional directivity in an arbitrarily configured flexible electret-based loudspeaker. In recent years, novel electret loudspeakers have attracted much interest due to their being lightweight, paper thin, and possessing excellent mid- to high-frequency responses. Increasing or decreasing the directivity of an electret loudspeaker makes it excellent for adoption to many applications, especially for directing sound to a particular area or specific audio location. Herein, we detail a novel electret loudspeaker that possesses various directivities and is based on various structures of spacers instead of having to use multichannel amplifiers and a complicated digital control system. In order to study the directivity of an electret loudspeaker based on an array structure which can be adopted for various applications, the horizontal and vertical polar directivity characteristics as a function of frequency were simulated by a finite-element analysis model. To validate the finite-element analysis model, the beam pattern of the electret loudspeaker was measured in an anechoic room. Both the simulated and experimental results are detailed in this article to validate the various assertions related to the directivity of electret cell-based smart speakers.

scholarly journals 3D Finite Element Analysis of Rotary Instruments in Root Canal Dentine with Different Elastic Moduli

2021 ◽  
Vol 11 (6) ◽  
pp. 2547 ◽  
Author(s):  
Carlo Prati ◽  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Alexandre Luiz Souto Borges ◽  
Maurizio Ventre ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Root Canal ◽  
Elastic Moduli ◽  
Reaction Force ◽  
Von Mises Stress ◽  
Elastic Behavior ◽  
Element Analysis ◽  
Heat Treated ◽  
Von Mises

The aim of the present investigation was to calculate the stress distribution generated in the root dentine canal during mechanical rotation of five different NiTi endodontic instruments by means of a finite element analysis (FEA). Two conventional alloy NiTi instruments F360 25/04 and F6 Skytaper 25/06, in comparison to three heat treated alloys NiTI Hyflex CM 25/04, Protaper Next 25/06 and One Curve 25/06 were considered and analyzed. The instruments’ flexibility (reaction force) and geometrical features (cross section, conicity) were previously investigated. For each instrument, dentine root canals with two different elastic moduli(18 and 42 GPa) were simulated with defined apical ratios. Ten different CAD instrument models were created and their mechanical behaviors were analyzed by a 3D-FEA. Static structural analyses were performed with a non-failure condition, since a linear elastic behavior was assumed for all components. All the instruments generated a stress area concentration in correspondence to the root canal curvature at approx. 7 mm from the apex. The maximum values were found when instruments were analyzed in the highest elastic modulus dentine canal. Strain and von Mises stress patterns showed a higher concentration in the first part of curved radius of all the instruments. Conventional Ni-Ti endodontic instruments demonstrated higher stress magnitudes, regardless of the conicity of 4% and 6%, and they showed the highest von Mises stress values in sound, as well as in mineralized dentine canals. Heat-treated endodontic instruments with higher flexibility values showed a reduced stress concentration map. Hyflex CM 25/04 displayed the lowest von Mises stress values of, respectively, 35.73 and 44.30 GPa for sound and mineralized dentine. The mechanical behavior of all rotary endodontic instruments was influenced by the different elastic moduli and by the dentine canal rigidity.

Finite Element Analysis of Main Stand of Ф140 Pipe Rolling Mill and Split Casting

2013 ◽  
Vol 690-693 ◽  
pp. 2327-2330
Author(s):  
Ming Bo Han ◽  
Li Fei Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rolling Mill ◽  
Analysis Model ◽  
Element Analysis ◽  
Pipe Rolling ◽  
Full Load ◽  
Finite Element Software ◽  
Theoretical Position ◽  
Technical Requirements

By using finite element software, the paper establishes the main stand analysis model of the Ф140 pipe rolling mill and provides the model analysis of main stand in cases of full load. Verify the design of main stand fully comply with the technical requirements .In this paper, it provides the theoretical position of split casting and welding method using electric slag welding.

scholarly journals Biomechanical assessment of different fixation methods in mandibular high sagittal oblique osteotomy using a three-dimensional finite element analysis model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charles Savoldelli ◽  
Elodie Ehrmann ◽  
Yannick Tillier
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Analysis Model ◽  
Element Analysis ◽  
Fixation Methods ◽  
Oblique Osteotomy ◽  
Von Mises

AbstractWith modern-day technical advances, high sagittal oblique osteotomy (HSOO) of the mandible was recently described as an alternative to bilateral sagittal split osteotomy for the correction of mandibular skeletal deformities. However, neither in vitro nor numerical biomechanical assessments have evaluated the performance of fixation methods in HSOO. The aim of this study was to compare the biomechanical characteristics and stress distribution in bone and osteosynthesis fixations when using different designs and placing configurations, in order to determine a favourable plating method. We established two finite element models of HSOO with advancement (T1) and set-back (T2) movements of the mandible. Six different configurations of fixation of the ramus, progressively loaded by a constant force, were assessed for each model. The von Mises stress distribution in fixations and in bone, and bony segment displacement, were analysed. The lowest mechanical stresses and minimal gradient of displacement between the proximal and distal bony segments were detected in the combined one-third anterior- and posterior-positioned double mini-plate T1 and T2 models. This suggests that the appropriate method to correct mandibular deformities in HSOO surgery is with use of double mini-plates positioned in the anterior one-third and posterior one-third between the bony segments of the ramus.

Wear analysis of eco-friendly non-asbestos friction-lining material applied in an automotive drum brake: Experimental and finite-element analysis

2021 ◽  
pp. 135065012110167
Author(s):  
Dinesh Shinde ◽  
Mukesh Bulsara ◽  
Jeet Patil
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surface Wear ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Drum Brake ◽  
Wear Analysis ◽  
Lining Material ◽  
Friction Lining

Brake friction lining material is the critical element of a braking system, since it provides friction resistance to the rotating drum for controlling automobiles. The present study involves wear analysis of newly developed eco-friendly non-asbestos friction lining material for automotive drum brake applications using experimental study, finite-element analysis, and microstructural investigations. Theoretical interpretation of braking force at different automobile speeds was derived using fundamentals. Specimen drum brake liner with eco-friendly material compositions was produced using an industrial hot compression molding process at one of the manufacturer. The surface wear of the liner was measured using an effective and accurate method. Furthermore, a finite-element analysis model was developed considering actual operating conditions and various components of the drum brake system. The model was elaborated for various result outcomes, including Von-Mises stresses and total deformation of components of the drum brake, and further used to estimate the surface wear of the friction lining material in terms of transverse directional deformation. Finally, microstructural analysis of the friction lining material was carried out using scanning electron microscopy and energy dispersive spectroscopy. From the results, it is seen that the developed friction lining material is wear resistant. The finite-element analysis model can be effectively utilized to study the tribological characteristics of friction lining materials.

Analysis of Nonlinear Flexural Behavior of Thick Composites With Fiber Waviness

1999 ◽  
Author(s):  
H.-J. Chun ◽  
S. W. Lee ◽  
I. M. Daniel
Keyword(s):  
Finite Element ◽  
Composite Plate ◽  
Current Model ◽  
Geometrical Nonlinearity ◽  
Mapping Method ◽  
Flexural Behavior ◽  
Analysis Model ◽  
Element Analysis ◽  
Fiber Waviness ◽  
Thick Composites

Abstract A finite element analysis model was developed to predict flexural behavior of thick composites with uniform, graded and localized fiber waviness. In the analyses, material and geometrical nonlinearties due to fiber waviness were incorporated into the model utilizing energy density and an incremental method. In the model, two kinds of geometrical nonlinearity were considered, one due to reorientation of fibers and the other due to difference of curvatures from one finite element to another during deformation. The finite element analyses utilize the iterative mapping method to incorporate these geometrical nonlinear factors. The model was used to predict not only the flexural behavior of a flat thick composite plate but also of a thick composite plate with initial curvature. Flat composite specimens with various degrees of fiber waviness were fabricated and four-point flexural tests were conducted. The predicted nonlinear behavior by the current model was compared with results from the thin slice model [7] and experiments. Good agreement was observed among them.

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