Application of the Nodal Integrated Finite Element Method to Cutting: a Preliminary Comparison with the “Traditional” FEM Approach

2011 ◽  
Vol 223 ◽  
pp. 172-181 ◽  
Author(s):  
Francesco Greco ◽  
Domenico Umbrello ◽  
Serena Di Renzo ◽  
Luigino Filice ◽  
I. Alfaro ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Large Deformation ◽  
Orthogonal Cutting ◽  
Fem Simulation ◽  
Cutting Process ◽  
Integration Technique ◽  
Mesh Distortion ◽  
Nodal Integration ◽  
Element Method

FEM implicit formulation shows specific limitations in processes such as cutting, where large deformation results in a heavy mesh distortion. Powerful rezoning-remeshing algorithms strongly reduce the effects of such a limitation but the computational times are significantly increased and additional errors are introduced. Nodal Integration is a recently introduced technique that allows finite element method to provide more reliable results when mesh becomes distorted in traditional FEMs. Furthermore, volumetric locking phenomenon seems to be avoided by using this integration technique instead of other methods, such as the coupled formulations. In this paper, a comparison between a “classical” FEM simulation and the Nodal Integration one is carried out taking into account a simple orthogonal cutting process.

Effects of Various Edge-Curve Types and Rotational Speeds of Disc Blades on Breaking Force and Energy Consumption in the Maize Stalk Chopping Process

2021 ◽  
Vol 37 (5) ◽  
pp. 951-965
Author(s):  
Peng Liu ◽  
Jin He ◽  
Hongwen Li ◽  
Qingjie Wang ◽  
Caiyun Lu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Energy Consumption ◽  
Fem Simulation ◽  
Influential Factor ◽  
List Type ◽  
Breaking Force ◽  
Field Validation ◽  
Validation Experiment ◽  
Element Method

HighlightsThe peak breaking force and energy consumption change in maize stalk were predicted by the FEM.A high SADBT reduced the PBFR and PBFS and increased the ECSC.The TRYDB had the most critical effect on the peak breaking force and energy consumption.Abstract. The mechanized retention of stalks is the primary method to avoid open burning. However, the variation in the breaking force and energy consumption in the chopping process of mechanized retention must be clarified. Therefore, based on the finite element method (FEM) and field validation experiments, the effects of various edge-curve types and rotational speeds of disc blades for maize stalk retention on the breaking force and energy consumption were examined. The test indices were the peak breaking force of the rind (PBFR) and stalk (PBFS), energy consumption of stalk chopping (ECSC), and energy transmission efficiency (ETE). The test factors were the spiral disc blade type (Archimedean, logarithmic, and sinusoidal-exponential spiral), slide-cutting angles of the disc blade tip (SADBT, 30°, 40°, 50°, and 60°), rotational speed of the Y-type blade (RSYB, 1400, 1600, 1800, 2000, 2200, and 2400 rpm), and transmission ratio between Y-type and disc blades (TRYDB, 0.25, 0.50, 0.75, and 1.0). The chopping process was divided into the cutting processes of the initial rind, rind and pith, final rind, and stalk end. The results showed that the SADBT, TRYDB, and RSYB had significant effects on the PBFR, PBFS, ECSC, and ETE. The most influential factor on all test indices was the TRYDB. The RSYB positively affected the PBFR, PBFS, and ECSC. The growth rates of the PBFR, PBFS, and ECSC increased with the TRYDB. The maximum PBFR, PBFS, and ETE values were obtained under an SADBT of 60°, and the maximum ECSC value was obtained under an SADBT of 40°. The difference in energy consumption between the field validation experiment and simulation was less than 10%, which proved the correct results of the FEM simulation. Keywords: Energy consumption, Finite element method, Maize stalk, Peak breaking force, Slide cutting.

A Reverse Approach in Optimizing Pass Parameters

2010 ◽  
Vol 113-116 ◽  
pp. 1707-1711
Author(s):  
Jian Hua Hu ◽  
Yuan Hua Shuang
Keyword(s):  
Neural Networks ◽  
Finite Element Method ◽  
Finite Element ◽  
Learning Process ◽  
Back Propagation ◽  
Fem Simulation ◽  
Steel Pipe ◽  
Good Convergence ◽  
Back Propagation Neural Networks ◽  
Element Method

A method combines a back propagation neural networks (BPNN) with the data obtained using finite element method (FEM) is introduced in this paper as an approach to solve reverse problems. This paper presents the feasibility of this approach. FEM results are used to train the BPNN. Inputs of the network are associated with dimension deviation values of the steel pipe, and outputs correspond to its pass parameters. Training of the network ensures low error and good convergence of the learning process. At last, a group of optimal pass parameters are obtained, and reliability and accuracy of the parameters are verified by FEM simulation.

FEM Simulation of the Effects of Residual Stress on Deformation of Gyroscope Frame

2010 ◽  
Vol 439-440 ◽  
pp. 838-841
Author(s):  
Jun Zhan ◽  
Gui Min Chen ◽  
Xiao Fang Liu ◽  
Qing Jie Liu ◽  
Qian Zhang
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Tensile Stress ◽  
Large Deformation ◽  
Deformation Process ◽  
Fem Simulation ◽  
Machining Process ◽  
The Core

Gyroscope is the core of an inertia system and made by machining process. Machining process imports large residual stress. The residual stress will be released and induces large deformation of gyroscope frame. In this paper, the effects of residual stress on deformation of gyroscope frame were simulated by finite element method. Different stress distribution leads different deformation. Compressive stress can make sample long and tensile stress make sample short. The stress released in deformation process which reduced about 90%.

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