scholarly journals DEVELOPMENT OF THE METAL RHEOLOGY MODEL OF HIGH-TEMPERATURE DEFORMATION FOR MODELING BY FINITE ELEMENT METHOD

2019 ◽  
Vol 2 ◽  
pp. 52-60 ◽  
Author(s):  
Oleg Markov ◽  
Oleksiy Gerasimenko ◽  
Leila Aliieva ◽  
Alexander Shapoval
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Relaxation ◽  
Hot Deformation ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Software Systems ◽  
Elastic Model ◽  
Communication Model ◽  
Element Method

It is shown that when modeling the processes of forging and stamping, it is necessary to take into account not only the hardening of the material, but also softening, which occurs during hot processing. Otherwise, the power parameters of the deformation processes are precisely determined, which leads to the choice of more powerful equipment. Softening accounting (processes of stress relaxation) will allow to accurately determine the stress and strain state (SSS) of the workpiece, as well as the power parameters of the processes of deformation. This will expand the technological capabilities of these processes. Existing commercial software systems for modeling hot plastic deformations based on the finite element method (FEM) do not allow this. This is due to the absence in these software products of the communication model of the component deformation rates and stresses, which would take into account stress relaxation. As a result, on the basis of the Maxwell visco-elastic model, a relationship is established between deformation rates and stresses. The developed model allows to take into account the metal softening during a pause after hot deformation. The resulting mathematical model is tested by experiment on different steels at different temperatures of deformation. The process of steels softening is determined using plastometers. It is established experimentally that the model developed by 89 ... 93 % describes the rheology of the metal during hot deformation. The relationship between the components of the deformation rates and stresses is established, which allows to obtain a direct numerical solution of plastic deformation problems without FED iterative procedures, taking into account the real properties of the metal during deformation. As a result, the number of iterations and calculations has significantly decreased.

scholarly journals Validation of the load-bearing capacity of the frame assembly of metal structures on the standard 2.440 series using IDEA StatiCa

2020 ◽  
Vol 10 (3) ◽  
pp. 406-419
Author(s):  
Denis A. Melnikov ◽  
◽  
Tatyana L. Dmitrieva ◽  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Sections ◽  
Limit State ◽  
Local Buckling ◽  
High Strength ◽  
Software Systems ◽  
Rigid Frame ◽  
Welding Forces ◽  
Element Method

The paper aims to study the actual operation of a rigid frame unit for coupling a crossbar with a column on high-strength bolts according to the standard 2.440-2 series using modern software systems of the component finite element method. Special attention was paid to the operation of nodal elements, as well as their stress-strain state. Based on the results of static calculations, the cross-sections of the elements under consideration, as well as the components of the node (plates, bolts, seams, etc.) were selected from the tables of the standard series. Subsequently, using the component finite element method serving as the basis of the IDEA StatiСa software, all the components of the node were mod-elled with respect to acting forces. The conducted calculations confirmed the suitability of the obtained node model for identifying inconsistencies in the series and modern standards. Using stresses on plates, bolt and welding forces, as well as several forms of vibration to assess the stability of compo-nents, the applicability of the node in question in the proposed configuration was evaluated. It turned out that the node failed to meet modern standards in terms of design conditions. Moreover, the serial bolts were overloaded by almost 38%, and some welds approached the limit state. When used in real conditions, this can lead to serious losses, including human lives. Recommendations are given for changing the specific configuration of the node in order to protect it from the destruction of any nature, including local buckling failure.

Preliminary Exploration of 2-Dimensional Seismic Response Analysis for Elastic Layered Model by ABAQUS

2014 ◽  
Vol 915-916 ◽  
pp. 72-75
Author(s):  
Xiao Bo Yu ◽  
Rui Sun ◽  
Xiao Fei Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Seismic Response ◽  
Good Choice ◽  
Response Analysis ◽  
Elastic Model ◽  
Seismic Response Analysis ◽  
Layered Model ◽  
Simple Boundary ◽  
Element Method

Finite element method is widely used in every field, in which ABAQUS is a typical product. For engineers and researchers, SHAKE91 is a good choice for seismic safety evaluation. For developing seismic response analysis for complicated cases, finite element method approach should be explored. An elastic layered model is built, which is calculated in SHAKE91 and ABAQUS respectively. The results of the two programs fitted well, which implies the correctness of the ABAQUS model. In the elastic model, simple boundary condition works well. In the future, more complex boundaries and dynamic constitutive models should be studied.

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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