First-order finite element model for modeling of a continuous facesheet deformable mirror

2002 ◽  
Author(s):  
Kelsey L. Rogers ◽  
Jeffrey D. Barchers
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Deformable Mirror ◽  
First Order

scholarly journals Design optimization of vehicle asynchronous motors based on fractional harmonic response analysis

2021 ◽  
Vol 12 (1) ◽  
pp. 689-700
Author(s):  
Ao Lei ◽  
Chuan-Xue Song ◽  
Yu-Long Lei ◽  
Yao Fu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Natural Frequency ◽  
Asynchronous Motor ◽  
Element Model ◽  
Design Parameters ◽  
Response Analysis ◽  
Harmonic Response ◽  
First Order ◽  
Harmonic Response Analysis

Abstract. To make vehicles more reliable and efficient, many researchers have tried to improve the rotor performance. Although certain achievements have been made, the previous finite element model did not reflect the historical process of the motor rotor well, and the rigidity and mass in rotor optimization are less discussed together. This paper firstly introduces fractional order into a finite element model to conduct the harmonic response analysis. Then, we propose an optimal design framework of a rotor. In the framework, objective functions of rigidity and mass are defined, and the relationship between high rigidity and the first-order frequency is discussed. In order to find the optimal values, an accelerated optimization method based on response surface (ARSO) is proposed to find the suitable design parameters of rigidity and mass. Because the higher rigidity can be transformed into the first-order natural frequency by objective function, this paper analyzes the first-order frequency and mass of a motor rotor in the experiment. The results proved that not only is the fractional model effective, but also the ARSO can optimize the rotor structure. The first-order natural frequency of asynchronous motor rotor is increased by 11.2 %, and the mass is reduced by 13.8 %, which can realize high stiffness and light mass of asynchronous motor rotors.

Modeling and Control of a Deformable Mirror

2002 ◽  
Vol 124 (2) ◽  
pp. 297-302 ◽  
Author(s):  
S. E. Winters ◽  
J. H. Chung ◽  
S. A. Velinsky
Keyword(s):  
Finite Element ◽  
Control System ◽  
Finite Element Model ◽  
Adaptive Optics ◽  
Element Model ◽  
Surface Shape ◽  
System Model ◽  
Deformable Mirror ◽  
Wavefront Aberration ◽  
Control System Model

A multi-input multi-output surface shape control system model is developed to study wavefront aberration correction. The plant model represents a deformable mirror and utilizes a finite element model that is validated using an actual prototype deformable mirror and an interferometer system. The sensor model is based on a Shack-Hartmann sensor, and the controller model is based on a least squares approach. The control system model is used to compare an available Gaussian model with the validated finite element model. Results clearly show the efficacy of the approach and the superiority of the finite element based method. The control approach is expected to be implemented on the adaptive optics system of the National Ignition Facility.

Stress-Strain Analysis of a Taper-Taper Adhesive-Bonded Joint Under Cylindrical Bending

1999 ◽  
Vol 121 (3) ◽  
pp. 374-380 ◽  
Author(s):  
Jack E. Helms ◽  
Chihdar Yang ◽  
Su-Seng Pang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Analytical Model ◽  
Plate Theory ◽  
Element Model ◽  
Variable Coefficients ◽  
Fortran Program ◽  
Cylindrical Bending ◽  
First Order ◽  
Bonded Joint

A model of a taper-taper adhesive-bonded joint under cylindrical bending has been derived using first-order laminated plate theory. Shear correction factors were used to account for transverse shear deformation. A FORTRAN program was written to integrate the resulting system of twelve simultaneous, linear, first-order, differential equations with variable coefficients. The Linear Shooting Method was used to solve the model. A finite element model was developed using the COSMOS/M commercial finite element package to verify the analytical model for a cross-ply laminate. The analytical model results agreed well with the finite element models and predicted peak adhesive stresses within about 2% of the finite element model.

The Abnormal Vibration Source Analysis of Automobile Drive Axle

2012 ◽  
Vol 605-607 ◽  
pp. 1134-1137
Author(s):  
Chang Hai Yang ◽  
Nian Cheng Guo ◽  
Hai Sheng Song ◽  
Wen Ku Shi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Rear Axle ◽  
Element Model ◽  
Source Analysis ◽  
Bench Test ◽  
Vibration Source ◽  
First Order ◽  
Drive Axle

Through a Transmission bench test of a certain automobile Drive axle Assembly ,the abnormal vibration in Rear axle can be found. This paper establishes three demensions modle and Finite element model of the Rear Drive axle Assembly and calculates the modal of the Assembly and Axle housing respectively. It can be found that the frequency of the abnormal vibration in the Rear axle Bench test Coincides with the frequence of the Assembly First-order bending.It presents that it is the Assembly Resonance that leads to the abnormal vibration of Rear axle,not just Axle housing Resonance

Buckling Analysis of Laminated Composite Beams by Using an Improved First Order Formulation

2021 ◽  
Vol 1033 ◽  
pp. 156-160
Author(s):  
Shammely Ayala ◽  
Augusto Vallejos ◽  
Roman Arciniega
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Virtual Work ◽  
Three Dimensional ◽  
Laminated Composite ◽  
Element Model ◽  
Composite Beams ◽  
Lagrange Polynomials ◽  
First Order ◽  
Laminated Composite Beams

In this work, a finite element model based on an improved first-order formulation (IFSDT) is developed to analyze buckling phenomenon in laminated composite beams. The formulation has five independent variables and takes into account thickness stretching. Three-dimensional constitutive equations are employed to define the material properties. The Trefftz criterion is used for the stability analysis. The finite element model is derived from the principle of virtual work with high-order Lagrange polynomials to interpolate the field variables and to prevent shear locking. Numerical results are compared and validated with those available in literature. Furthermore, a parametric study is presented.

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