scholarly journals Eliminating Underconstraint in Double Parallelogram Flexure Mechanisms

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Robert M. Panas ◽  
Jonathan B. Hopkins
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Experimental Measurement ◽  
Degrees Of Freedom ◽  
Dynamic Performance ◽  
Average Error ◽  
Static Stiffness ◽  
Element Analysis ◽  
Linkage Design ◽  
Analytical Expressions

We present an improved flexure linkage design for removing underconstraint in a double parallelogram (DP) linear flexural mechanism. This new linkage alleviates many of the problems associated with current linkage design solutions such as static and dynamic performance losses and increased footprint. The improvements of the new linkage design will enable wider adoption of underconstraint eliminating (UE) linkages, especially in the design of linear flexural bearings. Comparisons are provided between the new linkage design and existing UE designs over a range of features including footprint, dynamics, and kinematics. A nested linkage design is shown through finite element analysis (FEA) and experimental measurement to work as predicted in selectively eliminating the underconstrained degrees-of-freedom (DOF) in DP linear flexure bearings. The improved bearing shows an 11 × gain in the resonance frequency and 134× gain in static stiffness of the underconstrained DOF, as designed. Analytical expressions are presented for designers to calculate the linear performance of the nested UE linkage (average error < 5%). The concept presented in this paper is extended to an analogous double-nested rotary flexure design.

Optimal Design of the Vertical Machining Center Based on Stiffness Analysis

2011 ◽  
Vol 50-51 ◽  
pp. 68-72
Author(s):  
Yan Min Zhao ◽  
Zhi Jun Wu ◽  
Jian Fu Zhang ◽  
Ping Fa Feng ◽  
Ding Wen Yu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Static Stiffness ◽  
Element Analysis ◽  
Stiffness Analysis ◽  
Machining Center ◽  
Before And After ◽  
Machine Stiffness

Stiffness analysis plays an important role in the optimization of the machine tool. By analyzing the static stiffness, dynamic stiffness and natural frequency of the key components, we discussed how to improve static and dynamic performance of the whole machine. Through the finite element analysis method, weak parts of the vertical machining center are firstly identified based on static stiffness analysis. Due to the purposes of increasing the stroke in Y-direction, improving the whole machine stiffness and without increasing the whole machine weight, optimal designs are carried out mainly on the structures of the spindle box and the column. And the performance of the parts and the whole machine before and after optimization is compared by testing whether the stiffness is improved or not. We also conducted experiments, and the results are consistent with the results of finite element analysis.

scholarly journals Thermo-responsive and shape-morphing CF/GF composite skin: Full-field experimental measurement, theoretical prediction, and finite element analysis

2021 ◽  
Vol 160 ◽  
pp. 106874
Author(s):  
Jamal Seyyed Monfared Zanjani ◽  
Pouya Yousefi Louyeh ◽  
Isa Emami Tabrizi ◽  
Abdulrahman Saeed Al-Nadhari ◽  
Mehmet Yildiz
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Prediction ◽  
Experimental Measurement ◽  
Element Analysis ◽  
Full Field ◽  
Shape Morphing

Finite Element Analysis and Optimization of Long-Span Gantry NC Machining Center Structure

2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Method ◽  
Dynamic Performance ◽  
Plate Thickness ◽  
Element Model ◽  
Wall Structure ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Dynamic Performance Analysis

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.

Finite Element Analysis of Automobile Drive Axle Housing Based on ANSYS

2015 ◽  
Vol 741 ◽  
pp. 223-226
Author(s):  
Hai Bin Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Performance ◽  
Element Analysis ◽  
Shell Elements ◽  
Fea Model ◽  
Automobile Design ◽  
Housing Structure ◽  
Drive Axle ◽  
Drive Axle Housing

The performance of automobile drive axle housing structure affects whether the automobile design is successful or not. In this paper, the author built the FEA model of a automobile drive axle housing with shell elements by ANSYS. In order to building the optimization model of the automobile drive axle housing, the author studied the static and dynamic performance of it’s structure based on the model.

Adaptive Degrees-of-Freedom Finite Element Analysis of 3-D Transient Magnetic Problems

2020 ◽  
pp. 1-1
Author(s):  
Yunpeng Zhang ◽  
Xinsheng Yang ◽  
Huihuan Wu ◽  
Dingguo Shao ◽  
Weinong Fu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Degrees Of Freedom ◽  
Element Analysis

Workspace Comparison Between 3-PRR and 3-RPR Micro-Manipulator

2012 ◽  
Author(s):  
Yi Dong ◽  
Feng Gao ◽  
Yi Yue ◽  
Jin Feng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Degrees Of Freedom ◽  
The Other ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Structural Differences ◽  
Micro Manipulator

This paper presents two compliant micro-manipulators with different structures. One uses 3-PRR mechanism while the other one adopts 3-RPR mechanism. Both of the two micro-manipulators have two translational degrees of freedom (DOF) and one rotational DOF. But the properties, such as workspace, of the two micro-manipulators are not the same. In this paper, the workspaces are studied and compared. First, the structural differences are presented. Then, the stiffness derivations of the two micro-manipulators are given and the workspaces are calculated considering the properties of piezoelectric (PZT) actuators. Finally the finite element analysis and prototype experiments are performed to validate the obtained results.

Structural investigation of steel-reinforced epoxy granite machine tool column by finite element analysis

2019 ◽  
Vol 233 (11) ◽  
pp. 2267-2279 ◽  
Author(s):  
Prabhu Raja Venugopal ◽  
M Kalayarasan ◽  
PR Thyla ◽  
PV Mohanram ◽  
Mahendrakumar Nataraj ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cast Iron ◽  
Machine Tool ◽  
Dynamic Characteristics ◽  
Element Model ◽  
Static Stiffness ◽  
Element Analysis ◽  
Static And Dynamic Characteristics ◽  
Machining Center

Higher damping with higher static stiffness is essential for improving the static and dynamic characteristics of machine tool structures. The structural vibration in conventional machine tools, which are generally made up of cast iron and cast steel, may lead to poor surface finish and the dimensional inaccuracy in the machined products. It leads to the investigation of alternative machine tool structural materials such as concrete, polymer concrete, and epoxy granite. Although epoxy granite has a better damping capacity, its structural stiffness (Young's modulus) is one-third as compared to cast iron. Therefore, the present work represents optimization of the structural design of the vertical machining center column by introducing various designs of steel reinforcement in the epoxy granite structure to improve its static and dynamic characteristics using experimental and numerical approaches. A finite element model of the existing cast iron vertical machining center column has been developed and validated against the experimental data obtained using modal analysis. Furthermore, finite element models for various epoxy granite column designs have been developed and compared with the static and dynamic characteristics of cast iron column. A total of nine design configurations for epoxy granite column with steel reinforcement are evolved and numerical investigations are carried out by finite element analysis. The proposed final configuration with standard steel sections has been modeled using finite element analysis for an equivalent static stiffness and natural frequencies of about 12–20% higher than cast iron structure. Therefore, the proposed finite element model of epoxy-granite-made vertical machining center column can be used as a viable alternative for the existing column in order to achieve higher structural damping, equivalent or higher static stiffness and, easy and environmental-friendly manufacturing process.

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