scholarly journals Extending service life of rails in the case of a rail head defect

2021 ◽  
Vol 73 (02) ◽  
pp. 119-125
Keyword(s):  
Finite Element Method ◽  
Residual Life ◽  
Crack Size ◽  
Crack Plane ◽  
The Finite Element Method ◽  
Safe Operation ◽  
Bending Fatigue ◽  
Continued Use ◽  
Position And Orientation ◽  
Low Activity

Rails are subjected to the processes of wear, corrosion and contact and bending fatigue during their lifecycle. As a result of these processes, various types of damage and defects are formed in rails. The residual life of rails depends on the size, position, and orientation of defects. Maximum permissible crack-size values are calculated in this paper using the finite element method. The crack plane orientation relative to the contact surface plane is analysed. The dependence of the stress intensity factor on the crack area is established. This allows continued use of defective rails and safe operation on low-activity railways.

ENSURING INDUSTRIAL SAFETY DURING THE OPERATION OF TECHNOLOGICAL EQUIPMENT

2021 ◽  
Author(s):  
Илья Евгеньевич Харламов ◽  
Сергей Ильдусович Валеев
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Bearing Capacity ◽  
Software Package ◽  
Industrial Safety ◽  
Technological Equipment ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Safe Operation ◽  
Load Bearing Capacity

Методом конечных элементов с помощью программного комплекса ANSYS проведен анализ влияния дефекта основного металла типа «расслоение», в зависимости от глубины его залегания, на возможную безопасную эксплуатацию технологического оборудования. По результатам исследований установлено, что расслоение не оказывает существенного влияния на несущую способность оборудования, пока оно локально и не распространяется. The analysis of the influence of a base metal defect of the "stratification" type, depending on the depth of its occurrence, on the possible safe operation of technological equipment was carried out by the finite element method using the ANSYS software package. According to the results of the research, it was found that the stratification does not significantly affect the load-bearing capacity of the equipment, as long as it is local and does not spread.

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.

Comparison of Conventional and Pontic Fixed Partial Dentures Over Implants Using the Finite Element Method: Three-Dimensional Analysis of Cortical and Medullary Bone Stress

2020 ◽  
Vol 46 (3) ◽  
pp. 175-181
Author(s):  
Marcelo Bighetti Toniollo ◽  
Mikaelly dos Santos Sá ◽  
Fernanda Pereira Silva ◽  
Giselle Rodrigues Reis ◽  
Ana Paula Macedo ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Medullary Bone ◽  
Principal Stresses ◽  
Bone Stress ◽  
Bone Damage ◽  
Rehabilitation System ◽  
Minimum Requirements

Rehabilitation with implant prostheses in posterior areas requires the maximum number of possible implants due to the greater masticatory load of the region. However, the necessary minimum requirements are not always present in full. This project analyzed the minimum principal stresses (TMiP, representative of the compressive stress) to the friable structures, specifically the vestibular face of the cortical bone and the vestibular and internal/lingual face of the medullary bone. The experimental groups were as follows: the regular splinted group (GR), with a conventional infrastructure on 3 regular-length Morse taper implants (4 × 11 mm); and the regular pontic group (GP), with a pontic infrastructure on 2 regular-length Morse taper implants (4 × 11 mm). The results showed that the TMiP of the cortical and medullary bones were greater for the GP in regions surrounding the implants (especially in the cervical and apical areas of the same region) but they did not reach bone damage levels, at least under the loads applied in this study. It was concluded that greater stress observed in the GP demonstrates greater fragility with this modality of rehabilitation; this should draw the professional's attention to possible biomechanical implications. Whenever possible, professionals should give preference to use of a greater number of implants in the rehabilitation system, with a focus on preserving the supporting tissue with the generation of less intense stresses.

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