Simulating Research on Rod String’s Gyro Effect Caused by Eccentric Rotation in Circular Tube

2011 ◽  
Vol 130-134 ◽  
pp. 2294-2300
Author(s):  
Shi Min Dong ◽  
Wan Sheng Zhang ◽  
Guo Hong Chai ◽  
Ming Ming Xing ◽  
Hong Zhang
Keyword(s):  
Circular Tube ◽  
Element Model ◽  
Beam Element ◽  
Lateral Bending ◽  
Eccentric Rotation ◽  
Concentrated Force ◽  
Bending Deformation ◽  
Rotating Speed ◽  
Wave Numbers ◽  
Space Beam Element

Based on the influences of eccentrical rotating inertial centrifugal force and axial force on the rod string’s lateral bending deformation, the finite beam element model of rod string’s bending deformation is established. The constraint to rod string’s bending deflection exerted by inwall of circular tube and the distinction of the constraint to rod string’s deflection because of the different gaps between rod string to circular tube and coupling to circular tube are both taken into account. Meanwhile, removable spring elements with two directions are adopted, by which the non-linear contact problem between the rod string and circular tube is well resolved. Combining space beam element and spring elements with two directions, the corresponding finite element simulating program is also developed. Several simulating results can be shown as follows: eccentric rotation of rod string is able to produce gyro effect in vertical circular tube; The shape of the rod string’s deformation is a spiral which is thin on the upper-part and dense on the under-part; Gyro wave numbers are affected obviously by rotating speed, eccentricity, axial concentrated force, axial distributed force and length of the rod string.

scholarly journals Vibration characteristics of triple-gear-rotor system in compressed air energy storage under variable torque load

2021 ◽  
Vol 104 (1) ◽  
pp. 003685042098705
Author(s):  
Xinran Wang ◽  
Yangli Zhu ◽  
Wen Li ◽  
Dongxu Hu ◽  
Xuehui Zhang ◽  
...  
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Element Model ◽  
Rotor System ◽  
Dynamic Responses ◽  
System Response ◽  
Rotating Speed ◽  
Torque Load ◽  
Set Up ◽  
Two Stages

This paper focuses on the effects of the off-design operation of CAES on the dynamic characteristics of the triple-gear-rotor system. A finite element model of the system is set up with unbalanced excitations, torque load excitations, and backlash which lead to variations of tooth contact status. An experiment is carried out to verify the accuracy of the mathematical model. The results show that when the system is subjected to large-scale torque load lifting at a high rotating speed, it has two stages of relatively strong periodicity when the torque load is light, and of chaotic when the torque load is heavy, with the transition between the two states being relatively quick and violent. The analysis of the three-dimensional acceleration spectrum and the meshing force shows that the variation in the meshing state and the fluctuation of the meshing force is the basic reasons for the variation in the system response with the torque load. In addition, the three rotors in the triple-gear-rotor system studied show a strong similarity in the meshing states and meshing force fluctuations, which result in the similarity in the dynamic responses of the three rotors.

Finite element bending analysis of symmetric and non-symmetric functionally graded sandwich beams using a novel parabolic shear deformation theory

2021 ◽  
pp. 146442072110050
Author(s):  
Mohamed-Ouejdi Belarbi ◽  
Abdelhak Khechai ◽  
Aicha Bessaim ◽  
Mohammed-Sid-Ahmed Houari ◽  
Aman Garg ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Shear Deformation ◽  
Transverse Shear ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Element Model ◽  
Beam Element ◽  
Functionally Graded ◽  
Sandwich Beams

In this paper, the bending behavior of functionally graded single-layered, symmetric and non-symmetric sandwich beams is investigated according to a new higher order shear deformation theory. Based on this theory, a novel parabolic shear deformation function is developed and applied to investigate the bending response of sandwich beams with homogeneous hardcore and softcore. The present theory provides an accurate parabolic distribution of transverse shear stress across the thickness and satisfies the zero traction boundary conditions on the top and bottom surfaces of the functionally graded sandwich beam without using any shear correction factors. The governing equations derived herein are solved by employing the finite element method using a two-node beam element, developed for this purpose. The material properties of functionally graded sandwich beams are graded through the thickness according to the power-law distribution. The predictive capability of the proposed finite element model is demonstrated through illustrative examples. Four types of beam support, i.e. simply-simply, clamped-free, clamped–clamped, and clamped-simply, are used to study how the beam deflection and both axial and transverse shear stresses are affected by the variation of volume fraction index and beam length-to-height ratio. Results of the numerical analysis have been reported and compared with those available in the open literature to evaluate the accuracy and robustness of the proposed finite element model. The comparisons with other higher order shear deformation theories verify that the proposed beam element is accurate, presents fast rate of convergence to the reference results and it is also valid for both thin and thick functionally graded sandwich beams. Further, some new results are reported in the current study, which will serve as a benchmark for future research.

scholarly journals An Investigation into the Effect of Rolling Reduction on 3D Curved Parts Rolling Process

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1209
Author(s):  
Xiang Chang ◽  
Wenzhi Fu ◽  
Mingzhe Li ◽  
Xintong Wang ◽  
Weifeng Yang ◽  
...  
Keyword(s):  
Element Model ◽  
Rolling Process ◽  
Rolling Reduction ◽  
Shape Accuracy ◽  
Bending Deformation ◽  
Good Shape ◽  
Longitudinal Bending ◽  
Gap Height ◽  
Roll Gap ◽  
Forming Tools

Rolling technology based on arc-shaped rollers is a novel method for rapid manufacturing of 3D curved parts. The method uses a pair of arc-shaped rollers (a convex roller and a concave roller) as forming tools, forming an unevenly distributed roll gap. The sheet metal has both transverse bending and longitudinal uneven extension during rolling, so that surface parts with double curvature are processed. The curvature of the formed surface part can be changed by changing the rolling reduction. Changing the vertical distance between the rollers will cause the overall change of the roll gap height, which will inevitably have a great impact on the forming effect of formed 3D curved parts. In this paper, a finite element model and experiment with different rolling reductions was designed; the influence of rolling reduction on the bending deformation and shape accuracy of formed 3D curved parts was studied. The results show that, with the slight increase of rolling reduction (from 0.04 to 0.12 mm), the longitudinal bending deformation of the formed 3D curved part increases significantly, but its transversal bending is almost not affected. When the maximum rolling reduction is 0.04 and 0.06 mm (the corresponding minimum rolling reduction is less than or equal to zero), the shape accuracy of the formed 3D curved parts is not good enough; when the maximum rolling reduction is greater than 0.06 mm (the corresponding minimum rolling reduction is greater than zero), the shape accuracy of the formed 3D curved parts is significantly better. This indicates that, for the rolling of 3D curved parts based on arc-shaped rollers, ensuring that the minimum rolling reduction is greater than zero is the key to ensuring good shape accuracy of the formed 3D curved parts.

Contrastive Study on Finite Element Models of High-Strength Pipelines Crossing Active Faults

2016 ◽  
Vol 850 ◽  
pp. 957-964
Author(s):  
Wei Zheng ◽  
Hong Zhang ◽  
Xiao Ben Liu ◽  
Le Cai Liang ◽  
Yin Shan Han
Keyword(s):  
Finite Element ◽  
Design Method ◽  
Active Faults ◽  
Shell Element ◽  
High Strength ◽  
Element Model ◽  
Beam Element ◽  
Finite Element Models ◽  
Fixed Boundary ◽  
Equivalent Boundary

There is a potential for major damage to the pipelines crossing faults, therefore the strain-based design method is essential for the design of buried pipelines. Finite element models based on soil springs which are able to accurately predict pipelines’ responses to such faulting are recommended by some international guidelines. In this paper, a comparative analysis was carried out among four widely used models (beam element model; shell element model with fixed boundary; shell element model with beam coupled; shell element model with equivalent boundary) in two aspects: differences of results and the efficiency of calculation. The results show that the maximum and minimum strains of models coincided with each other under allowable strain and the calculation efficiency of beam element model was the highest. Besides, the shell element model with beam coupled or equivalent boundary provided the reasonable results and the calculation efficiency of them were higher than the one with fixed boundary. In addition, shell element model with beam coupled had a broader applicability.

Calculating Mechanics Characteristics of Single-Walled Carbon Nanotube Materials by Finite Element Method

2017 ◽  
Vol 730 ◽  
pp. 548-553
Author(s):  
Jing Ge ◽  
Hao Jiang ◽  
Zhen Yu Sun ◽  
Guo Jun Yu ◽  
Bo Su ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Radial Direction ◽  
Element Model ◽  
Beam Element ◽  
Beam Position ◽  
Single Walled Carbon ◽  
Finite Element Software ◽  
Calculation Results ◽  
The Moment

In this paper, we establish the mechanical property analysis of Single-walled Carbon Nanotubes (SWCNTs) modified beam element model based on the molecular structural mechanics method. Then we study the mechanical properties of their radial direction characteristics using the finite element software Abaqus. The model simulated the different bending stiffness with rectangular section beam elements C-C chemical force field. When the graphene curled into arbitrary chirality of SWCNTs spatial structure, the adjacent beam position will change the moment of inertia of the section of the beam. Compared with the original beam element model and the calculation results, we found that the established model largely reduced the overestimate of the original model of mechanical properties on the radial direction of the SWCNTs. At the same time, compared with other methods available in the literature results and the experimental data, the results can be in good agreement.

How the height and the area of the annulus fibrosus affect the range of motion behavior: A stochastic analysis

2018 ◽  
Vol 233 (10) ◽  
pp. 1985-1992
Author(s):  
Héctor E Jaramillo S
Keyword(s):  
Finite Element ◽  
Range Of Motion ◽  
Annulus Fibrosus ◽  
Element Model ◽  
Axial Rotation ◽  
Disc Height ◽  
Lateral Bending ◽  
Analytic Equation ◽  
Geometrical Properties ◽  
Flexion Extension

The annulus fibrosus has substantial variations in its geometrical properties (among individuals and between levels), and plays an important role in the biomechanics of the spine. Few works have studied the influence of the geometrical properties including annulus area, anterior / posterior disc height, and over the range of motion, but in general these properties have not been reported in the finite element models. This paper presents a probabilistic finite element analyses (Abaqus 6.14.2) intended to assess the effects of the average disc height ( hp) and the area ( A) of the annulus fibrosus on the biomechanics of the lumbar spine. The annulus model was loaded under flexion, extension, lateral bending, and axial rotation and analyzed for different combinations of hpand A in order to obtain their effects over the range of motion. A set of 50 combinations of hp(mean = 18.1 mm, SD = 3.5 mm) and A (mean = 49.8%, SD = 4.6%) were determined randomly according to a normal distribution. A Yeoh energy function was used for the matrix and an exponential function for the fibers. The range of motion was more sensitive to hpthan to A. With regard to the range of motion the segment was more sensitive in the following order: flexion, axial rotation, extension, and lateral bending. An increase of the hpproduces an increase of the range of motion, but this decreases when A increases. Comparing the range of motion with the experimental data, on average, 56.0% and 73.0% of the total of data were within the experimental range for the L4–L5 and L5–S1 segments, respectively. Further, an analytic equation was derived to obtain the range of motion as a function of the hpand A. This equation can be used to calibrate a finite element model of the spine segment, and also to understand the influence of each geometrical parameter on the range of motion.

scholarly journals A FEA Method for Mathematical Calculation and Prediction Analysis Cross-sectional Ovalization of Tubes under Rotary Straightening

2021 ◽  
Vol 2083 (4) ◽  
pp. 042057
Author(s):  
Ziqian Zhang ◽  
Ying Zhong
Keyword(s):  
Process Parameters ◽  
Element Model ◽  
Simulation Method ◽  
Stress And Strain ◽  
Cross Sectional ◽  
Bending Deformation ◽  
Deformation Stage ◽  
Thin Walled Pipe ◽  
Thin Walled ◽  
Flattening Process

Abstract The section flattening phenomenon (namely Bazier effect) will occur in the large bending deformation stage of thin-walled pipe in the continuous straightening process. The maximum section flattening amount and the residual section flattening amount are important process parameters, which are the basis for calculating the subsequent process parameters of the flattening circle, and directly determine the roundness of the final pipe and the product quality. However, it is hard to be obtained by the theoretical or experimental methods. Therefore, based on the structure and process parameters of the leveler, a finite element model was built to simulate the section flattening process. Then, ANSYS/LS-DYNA software was used to dynamically simulate the bending flattening phenomenon of thin-walled pipe in the continuous straightening process, and the stress and strain nephographic of the flattening deformation zone was obtained. By recording the position curve of the key nodes in the preventing process, the section flattening amount of the thin-walled pipe in the large bending deformation stage in the continuous straightening process was determined. The simulation results show that the dynamic simulation method can effectively predict the section flattening of thin-walled pipe in the process of continuous straightening.

Finite Element Analysis for the Crankshaft of the Piston Compressor

2010 ◽  
Vol 102-104 ◽  
pp. 17-21
Author(s):  
Bin Zhao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Natural Frequencies ◽  
Piston Compressor ◽  
Element Model ◽  
Ansys Software ◽  
Element Analysis ◽  
Rotating Speed ◽  
Dynamical Characteristics ◽  
The Finite Element Model

In order to study the static and dynamical characteristics of the crankshaft, ANSYS software was used to carry out the corresponding calculations. The entity model of the crankshaft was established by UG software firstly, and then was imported into ANSYS software for meshing, and then the finite element model of the crankshaft was constructed. The crankshaft satisfied the requirement of stiffness and strength through static analysis. The top six natural frequencies and corresponding shapes were acquired through modal analysis, and the every order critical rotating speed of the crankshaft was calculated. The fatigue life of the crank was calculated by fatigue module of ANSYS software finally. These results offered the theoretical guidance for designing, manufacturing and repairing the crankshaft.

scholarly journals Modelling a Cracked Beam Structure Using the Finite Element Displacement Method

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Hui Long ◽  
Yilun Liu ◽  
Changzheng Huang ◽  
Weihui Wu ◽  
Zhaojun Li
Keyword(s):  
Finite Element ◽  
Dynamic Model ◽  
Structural Parameters ◽  
Element Model ◽  
Beam Element ◽  
The Finite Element Method ◽  
Displacement Method ◽  
Beam Structure ◽  
Cracked Beam ◽  
Local Flexibility

A new model is presented for studying the effects of crack parameters on the dynamics of a cracked beam structure. The model is established by the finite element displacement method. In particular, the stiffness matrix of the cracked beam element is firstly derived by the displacement method, which does not need the flexibility matrix inversion calculation compared with the previous local flexibility approaches based on the force method. Starting with a finite element model of cracked beam element, the equation of strain energy of a cracked beam element is formed by the displacement method combined with the linear fracture mechanics. Then, based on the finite element method, the dynamic model of the cracked beam structure is obtained. The results show that the dynamic model discovers the internal relation between the dynamic characteristics of cracked beam structure and structural parameters, material parameters, and crack parameters. Finally, an example is presented to validate the proposed dynamic model.

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