scholarly journals Estimation of Specific Cutting Energy in an S235 Alloy for Multi-Directional Ultrasonic Vibration-Assisted Machining Using the Finite Element Method

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 567 ◽  
Author(s):  
Luis C. Flórez García ◽  
Hernán A. González Rojas ◽  
Antonio J. Sánchez Egea
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Carbon Steel ◽  
Cutting Parameters ◽  
Machining Process ◽  
Specific Cutting Energy ◽  
The Finite Element Method ◽  
Turning Process ◽  
Cutting Energy ◽  
Element Method

The objective of this work is to analyze the influence of the vibration-assisted turning process on the machinability of S235 carbon steel. During the experiments using this vibrational machining process, the vibrational amplitude and frequency of the cutting tool were adjusted to drive the tool tip in an elliptical or linear motion in the feed direction. Furthermore, a finite element analysis was deployed to investigate the mechanical response for different vibration-assisted cutting conditions. The results show how the specific cutting energy and the material’s machinability behave when using different operational cutting parameters, such as vibration frequency and tool tip motion in the x-axis, y-axis, and elliptical (x-y plane) motion. Then, the specific cutting energy and material’s machinability are compared with a conventional turning process, which helps to validate the finite element method (FEM) for the vibration-assisted process. As a result of the operating parameters used, the vibration-assisted machining process leads to a machinability improvement of up to 18% in S235 carbon steel. In particular, higher vibration frequencies were shown to increase the material’s machinability due to the specific cutting energy decrease. Therefore, the finite element method can be used to predict the vibration-assisted cutting and the specific cutting energy, based on predefined cutting parameters.

Modeling of the impact of hold-down forces on the accuracy of the workpiece shape using the finite element method

2021 ◽  
pp. 9-20
Author(s):  
A.V. Zaitsev ◽  
A.N. Izosimov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
The Body ◽  
Machining Process ◽  
Mechanical Processing ◽  
The Finite Element Method ◽  
The Cross ◽  
The Impact ◽  
Element Method

In the article, the modeling of the impact of hold-down forces on the accuracy of the shape of the workpiece using the finite element method was carried out. The operation of mechanical processing (turning cut) of a workpiece of the body of rotation type on a milling machine with basing and fixing along the inner cylindrical surface of the workpiece is considered. The study was conducted for four different types of machine retaining devices used on machines of this group. A consistent description and illustration of the method of modeling the process of the impact of hold-down forces on the workpiece is made for each type of the device under consideration. The force constraints and effects imposed on the model are described and illustrated, the parameters of the finite element grid used in modeling are presented, the displacement profiles obtained in the modeling process and the stages of modeling the machining process are described, and the values of the largest deviations from the shape of the workpiece are determined. The results of the modeling are presented: a qualitative picture of the shape errors obtained as a result of mechanical processing — the values of the largest deviation from the roundness and the largest deviation from the cross-section profile of the workpiece to be processed, as well as the shape of the cutting obtained in the cross-section of the workpiece for each type of the devices under consideration. On the basis of the obtained results, estimates of the degree of accuracy of the shape and the relative geometric accuracy provided by the considered devices were made in accordance with GOST 24643–81. The conclusion is made about the suitability of using the considered variants of machine retaining devices for the proposed technological process according to the criterion of the provided accuracy of the shape of the processed surface. English version of the article is available at URL: https://panor.ru/articles/modeling-the-influence-of-the-fastening-forces-on-the-accuracy-of-the-workpiece-shape-using-the-finite-element-method/65043.html

scholarly journals Finite element simulations of conventional and ultrasonically assisted turning processes with plane and textured cutting inserts

2019 ◽  
Vol 3 (1) ◽  
pp. 54-68
Author(s):  
Varun Sharma ◽  
Pulak M. Pandey ◽  
Uday S. Dixit ◽  
Anish Roy ◽  
Vadim V. Silberschmidt
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cutting Force ◽  
Cutting Forces ◽  
The Finite Element Method ◽  
Turning Process ◽  
Texture Pattern ◽  
Cutting Inserts ◽  
Force Variation ◽  
Element Method

This paper investigates the performance of conventional turning and ultrasonically assisted turning (UAT) processes with plane and textured cutting inserts. Simulations based on the finite-element method were carried out using a software package ABAQUS/Explicit (Dassault Systemes, France). The obtained results were validated experimentally by employing a specially developed UAT setup. The purpose of the paper is to analyze cutting-force variation by the use of textured cutting inserts. Optimized dimensions of the texture pattern were used to model textured cutting inserts. The cutting-force variation in UAT was assessed with finite-element method, confirming diminishing cutting forces at a tool–workpiece interface during a noncontact time. The use of the textured cutting inserts in the UAT process resulted in the lowest cutting forces when compared to a plane tool in UAT as well as both plane and textured tools in the conventional turning process.

scholarly journals Analytical determination and validation by finite elements method of hydrogen weld of carbon steel after post-heating

2020 ◽  
pp. 297-297
Author(s):  
José Meseguer-Valdenebro ◽  
Antonio Portoles ◽  
Eusebio Martínez-Conesa
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Phase Transformation ◽  
Carbon Steel ◽  
Base Material ◽  
Welding Process ◽  
Reference Method ◽  
Analytical Determination ◽  
The Finite Element Method ◽  
Element Method

The objective of this work is to determine analytically the amount of hydrogen residual in a weld after having carried out post-heating for a certain period of time in order to reduce the risk of cold cracking due to the presence of hydrogen in the weld and its validation by the finite element method. Post-heating is a variable present in the welding procedures and therefore it is mandatory in those welds that require it. This work can be helpful to determine both numerically by the finite element method and analytically the post-heating suitable in a welding process depending on that process, the welded material and the base material. In this work, the phase transformation and time difference of the phase transformation between the weld metal and base metal are not considered. The diffusivity values are those used by the reference method that analytically calculates the residual hydrogen in a carbon steel weld. There are two values of hydrogen diffusivity (minimum value and maximum value) in this way the diffusivity values that represent all types of carbon steel are collected. The least amount of hydrogen in the weld is with a post-heating to 200?C, producing a decrease in hydrogen in the weld at a higher speed than with the rest of temperatures below this.

Simulation of tuning graphene plasmonic behaviors by ferroelectric domains for self-driven infrared photodetector applications

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20868-20875 ◽  
Author(s):  
Junxiong Guo ◽  
Yu Liu ◽  
Yuan Lin ◽  
Yu Tian ◽  
Jinxing Zhang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Interfacial Effect ◽  
Infrared Photodetector ◽  
The Finite Element Method ◽  
Ferroelectric Domains ◽  
Element Method

We propose a graphene plasmonic infrared photodetector tuned by ferroelectric domains and investigate the interfacial effect using the finite element method.

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