scholarly journals Dynamic Modeling and Frequency Characteristic Analysis of a Novel 3-PSS Flexible Parallel Micro-Manipulator

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 678
Author(s):  
Jun Ren ◽  
Qiuyu Cao
Keyword(s):  
Finite Element ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Frequency Characteristic ◽  
Natural Frequencies ◽  
Mobile Platform ◽  
Characteristic Analysis ◽  
Working Space ◽  
Micro Manipulator ◽  
Spherical Hinge

Dynamic modeling and frequency characteristic analysis of a novel 3-PSS (three-prismatic-spherical-spherical) flexible parallel micro-manipulator with three translational DOF in space were investigated in this paper. Firstly, the kinematics analysis was developed based on the pseudo-rigid body model. The Jacobian matrix and the relationship between the micro angular deformation of the flexible spherical hinge and the end pose of mobile platform were respectively obtained by employing vector closed-loop method and coordinate transformation method. Then, taking into account the elastic strain energy of the flexible spherical hinge, dynamic model of this mechanism was established via Lagrange equations, and the expression of natural frequency was further derived. Combined with a set of given parameters, natural frequencies of the system were calculated by using MATLAB software. For the comparison purpose, a simulated modal analysis of the mechanism with the same parameters was also performed by employing finite element ANSYS software. Results from numerical calculation and finite element simulation indicated that maximum error of their natural frequencies was 2.71%, which verified the correctness of the theoretical dynamic model. Finally, variations of natural frequencies with changes of the basic parameters were analyzed. Analysis results show that natural frequencies increase with the increase of the bending stiffness kbm of flexible spherical hinge and the difference in radius Er between static platform and mobile platform, while decrease with the increase of the length l of the link rod and the masses of the main components of mechanism. Besides, it can be further drawn from these obtained results that the natural frequencies increase with the increase of the angle θl between the link rod and the z axis of reference coordinate system. Considering that the increase of the stiffness kbm and the angle θl will reduce the scope of working space, it is recommended in designing the structure to choose a set of larger stiffness kbm and angle θl as much as possible under the premise of satisfying the working space.

Dynamic Modeling and Optimal Design of a 2R Compliant Mechanism

2017 ◽  
Author(s):  
Wenshuo Ma ◽  
Yan Xie ◽  
Jingjun Yu ◽  
Xu Pei
Keyword(s):  
Optimal Design ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Dynamic Performance ◽  
Dynamic Problems ◽  
Numerical Result

Dynamic performance is of great importance to compliant mechanisms which are employed in dynamic applications, especially if the dynamic problems in DOC (degree of constraint) directions are to be met. An investigation on the dynamic characteristics of a 2R compliant mechanism is presented. Based on the substructure techniques, the in-plane dynamic model of the preceding compliant mechanisms is developed. The natural frequencies and sensitivities are then analyzed. The numerical result verifies the validity of the proposed method. Finally, optimal design of compliant mechanism is investigated.

Parametric Design and Modal Analysis on Four-Order Elliptical Gear

2013 ◽  
Vol 423-426 ◽  
pp. 1516-1519
Author(s):  
Zhi Dong Huang ◽  
An Min Hui ◽  
Guang Yang ◽  
Rui Yang Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Response ◽  
Modal Analysis ◽  
Dynamic Model ◽  
Natural Frequencies ◽  
Parametric Design ◽  
Three Dimensional ◽  
Response Analysis ◽  
Dynamic Design

The characteristics of four-order elliptical gear is analyzed. The parameters of four-order elliptical gear are chosen and calculated. The three-dimensional solid modeling of four-order elliptical gear is achieved. The dynamic model of four-order elliptical gear is established by finite element method and modal analysis of four-order elliptical gear is investigated. The natural frequencies and major modes of the first six orders are clarified. The method and the result facilitate the dynamic design and dynamic response analysis of high-order elliptical gear.

Finite Element Analysis of the Screen Box of the Combined Vibrating Screen Based on ANSYS

2011 ◽  
Vol 128-129 ◽  
pp. 1316-1320
Author(s):  
Nian Qin Guo ◽  
Wei Liu ◽  
Wei Ping Huang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Static Load ◽  
Natural Frequencies ◽  
Element Model ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Vibrating Screen ◽  
Stress And Deformation ◽  
The Finite Element Model

The finite element model of the combined vibrating screen was established by using ANSYS. Modal characteristic analysis and static analysis on the whole unit of screen box were done, and natural frequencies and modal shapes in the top 15 orders were obtained, distribution regularities of stress and deformation of each part of the screen box under the static load were revealed, providing the necessary basis for the improvement design and research on screen box.

FEM-Based Dynamic Performances of HSK Spindle/Toolholder Interface

2010 ◽  
Vol 431-432 ◽  
pp. 142-145
Author(s):  
Song Zhang ◽  
Xing Ai
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Modeling ◽  
Rotational Speed ◽  
High Speed ◽  
Natural Frequencies ◽  
Contact Stiffness ◽  
High Speed Machining ◽  
Structural Damping ◽  
Dynamic Performances

In the present paper, a dynamic modeling approach is presented to determine the contact stiffness and structural damping between the spindle and the toolholder; and then, the spindle and the toolholder are coupled by some springs and dampers. Finally, the dynamic performances of the HSK-A63 spindle/toolholder interface are analyzed by means of finite element method (FEM). From the simulated results, it can be seen that the natural frequencies of the first two modes increase with the increase of the rotational speed, which make the HSK spindle/toolholder interface appear good dynamic performances and be suitable for high-speed machining.

Dynamic Modeling of a Slider-Crank Mechanism Under Joint Wear

2008 ◽  
Author(s):  
Saad Mukras ◽  
Nate Mauntler ◽  
Nam Ho Kim ◽  
Tony Schmitz ◽  
W. Gregory Sawyer
Keyword(s):  
Finite Element ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Iterative Scheme ◽  
Wear Depth ◽  
Wear Prediction ◽  
Joint Force ◽  
Joint Forces ◽  
Modeling Techniques ◽  
Crank Mechanism

A study of how joint wear affects the kinematics of a simple slider-crank mechanism and in turn how change in kinematics of the mechanism affects the joint wear is presented. The coupling between joint wear and system kinematics is modeled by integrating a wear prediction process, built upon a widely used finite-element-based iterative scheme, with the dynamic model that has an imperfect joint whose kinematics changes progressively according to joint wear. Three different modeling techniques are presented based on different assumptions, and their performances are compared in terms of joint forces and wear depths. It turns out that the joint wear increases the joint force and accelerates the wear progress. The accuracy of integrated dynamic model is validated by measuring joint force and wear depth of the slider-crank mechanism. Details of instrumentation are also presented.

Dynamic Modeling and Dynamic Characteristic Analysis of a New Concept Stratospheric V-Shaped Airship

2011 ◽  
Vol 145 ◽  
pp. 37-42
Author(s):  
Gang Liu ◽  
Fan Wang ◽  
Guan Xin Hong
Keyword(s):  
Dynamic Characteristic ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Added Mass ◽  
Open Loop ◽  
Weight Class ◽  
Characteristic Analysis ◽  
Aerodynamic Efficiency ◽  
Near Space ◽  
Engine Thrust

It has important scientific and engineering applications for near-space platform to design the buoyancy-lifting aircraft with both bigger volume and higher aerodynamic efficiency. This paper provided a design of a new concept V-shaped airship which has a capacity of buoyancy-lifting configuration than the same-weight class conventional airship. In addition, two engines could provide rolling, yawing and pitching moments for the V-shaped airship by changing directions and creating different thrust. Based on the thick aerofoil, the geometry of this V-shaped configuration was then used to develop an aerodynamic estimating model for the V-shaped airship. It renewed estimating methods for the added mass, inertia, the forces and the moments including aerodynamic and engine thrust of the V-shaped airship. Then this paper described a 6 Degree of Freedom (DOF) dynamic model for the V-shaped airship. The open-loop disturbance characteristic of the dynamic model was analyzed across a range of flight conditions and the added mass of the V-shaped airship were compared with the same weight-class teardrop-shaped dull-hull airship. Finally, the characteristics of buoyancy and lift between V-shaped airship and dull-hull airship were compared at different velocity. The results show that the aerodynamic efficiency of the V-shaped airship is improved obviously from the same-weight class dull-hull airship across a range of flight velocity.

Seismic Response Spectrum Analysis of the Single Vertical Centrifugal Pump

2011 ◽  
Vol 121-126 ◽  
pp. 1450-1454
Author(s):  
He Li ◽  
Shi Bo Fu ◽  
Qing Rong Zhao ◽  
Bang Chun Wen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Seismic Response ◽  
Dynamic Model ◽  
Centrifugal Pump ◽  
Spectrum Analysis ◽  
Natural Frequencies ◽  
Response Spectrum ◽  
Response Spectrum Analysis ◽  
Spectrum Method

A dynamic model of the single vertical centrifugal pump was established to avoid seismic disadvantageous direction towards the direction of continually occurring earthquake during the designing and the installing. Finite element method was used to analyse the single vertical centrifugal pump and educe the first 20 natural frequencies and vibration shapes. Response spectrum method was adopted to do earthquake analysis. Response spectrum was inputted from different directions for getting different displacements and loads. According to the results, model’s direction of 45°~75° should be located at the direction of continually occurring earthquake to avoid the maximum vibration.

Dynamic model for high-speed rotors based on their experimental characterization

2017 ◽  
Vol 2 (4) ◽  
pp. 25
Author(s):  
L. A. Montoya ◽  
E. E. Rodríguez ◽  
H. J. Zúñiga ◽  
I. Mejía
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Experimental Characterization ◽  
Rotating Systems ◽  
Computing Performance ◽  
The Impact ◽  
Stiffness Distribution ◽  
Good Agreement

Rotating systems components such as rotors, have dynamic characteristics that are of great importance to understand because they may cause failure of turbomachinery. Therefore, it is required to study a dynamic model to predict some vibration characteristics, in this case, the natural frequencies and mode shapes (both of free vibration) of a centrifugal compressor shaft. The peculiarity of the dynamic model proposed is that using frequency and displacements values obtained experimentally, it is possible to calculate the mass and stiffness distribution of the shaft, and then use these values to estimate the theoretical modal parameters. The natural frequencies and mode shapes of the shaft were obtained with experimental modal analysis by using the impact test. The results predicted by the model are in good agreement with the experimental test. The model is also flexible with other geometries and has a great time and computing performance, which can be evaluated with respect to other commercial software in the future.

Static and Dynamic Characteristic Analysis of the Tower for Vertical Axis Wind Turbine Based on Finite Element Method

2012 ◽  
Vol 229-231 ◽  
pp. 613-616
Author(s):  
Yan Jue Gong ◽  
Yuan Yuan Zhang ◽  
Fu Zhao ◽  
Hui Yu Xiang ◽  
Chun Ling Meng ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wind Turbine ◽  
Dynamic Characteristic ◽  
Optimization Design ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Characteristic Analysis ◽  
Support Structure ◽  
Element Method

As an important part of the vertical axis wind turbine, the support structure should have high strength and stiffness. This article adopts finite element method to model a kind of tower structure of the vertical axis wind turbine and carry out static and modal analysis. The static and dynamic characteristic results of tower in this paper provide reference for optimization design the support structure of wind turbine further.

Bionic design of the tower for wind turbine

2021 ◽  
pp. 095440622110046
Author(s):  
Yuqiao Zheng ◽  
Fugang Dong ◽  
Huquan Guo ◽  
Bingxi Lu ◽  
Zhengwen He
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Maximum Stress ◽  
Natural Frequencies ◽  
Bionic Design ◽  
Analytic Hierarchy ◽  
Element Analysis ◽  
Maximum Deformation ◽  
Overall Stability ◽  
Biological Selection

The study obtains a methodology for the bionic design of the tower for wind turbines. To verify the rationality of the biological selection, the Analytic Hierarchy Procedure (AHP) is applied to calculate the similarity between the bamboo and the tower. Creatively, a bionic bamboo tower (BBT) is presented, which is equipped with four reinforcement ribs and five flanges. Further, finite element analysis is employed to comparatively investigate the performance of the BBT and the original tower (OT) in the static and dynamic. Through the investigation, it is suggested that the maximum deformation and maximum stress can be reduced by 5.93 and 13.75% of the BBT. Moreover, this approach results in 3% and 1.1% increase respectively in the First two natural frequencies and overall stability.

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