scholarly journals Numerical modeling of porous ceramics microstructure

2019 ◽  
Vol 1 (22) ◽  
pp. 5-17 ◽  
Author(s):  
Danuta Miedzińska

The presented research is directed to the porous ceramics microstructural behaviour assessment with the use of numerical methods. Such new material can be used for thermal insulation, filters, bio-scaffolds for tissue engineering, and preforms for composite fabrication. One of the newest and most interesting applications, considered in this work, is a usage of those materials for production of proppants for hydraulic fracturing of shale rocks. The hydraulic fracturing is a method of gas recovery from unconventional reservoirs. A large amount of fracturing fluid mixed with proppant (small particles of sand or ceramics) is pumped into the wellbore and its pressure causes the rock cracking and gas release. After fracturing the fluid is removed from the developed cracks leaving the proppant supporting the fracture. In the paper the grain porous ceramics which is used for proppant particles preparation was studied. The influence of grains distribution on the porous ceramics mechanical behaviour during compression was simulated with the use of finite element method.

2016 ◽  
Vol 35 ◽  
pp. 873-881 ◽  
Author(s):  
Junchao Li ◽  
Zhengdong Lei ◽  
Huiying Tang ◽  
Changbing Tian ◽  
Bin Gong

2017 ◽  
Vol 54 (2) ◽  
pp. 195-202
Author(s):  
Vasile Nastasescu ◽  
Silvia Marzavan

The paper presents some theoretical and practical issues, particularly useful to users of numerical methods, especially finite element method for the behaviour modelling of the foam materials. Given the characteristics of specific behaviour of the foam materials, the requirement which has to be taken into consideration is the compression, inclusive impact with bodies more rigid then a foam material, when this is used alone or in combination with other materials in the form of composite laminated with various boundary conditions. The results and conclusions presented in this paper are the results of our investigations in the field and relates to the use of LS-Dyna program, but many observations, findings and conclusions, have a general character, valid for use of any numerical analysis by FEM programs.


2021 ◽  
Vol 11 (11) ◽  
pp. 5170
Author(s):  
Marek Krawczuk ◽  
Magdalena Palacz

Modern engineering practice requires advanced numerical modeling because, among other things, it reduces the costs associated with prototyping or predicting the occurrence of potentially dangerous situations during operation in certain defined conditions. Different methods have so far been used to implement the real structure into the numerical version. The most popular have been variations of the finite element method (FEM). The aim of this Special Issue has been to familiarize the reader with the latest applications of the FEM for the modeling and analysis of diverse mechanical problems. Authors are encouraged to provide a concise description of the specific application or a potential application of the Special Issue.


Author(s):  
Я.Б. Немировский ◽  
И.В. Шепеленко ◽  
С.Е. Шейкин ◽  
Ю.А. Цеханов ◽  
Ф.Й. Златопольский ◽  
...  

Разработан алгоритм и проведена оценка прочности сборных твердосплавных элементов со сплошной и дискретной рабочими поверхностями. Получены зависимости, позволяющие установить связь между конструктивными параметрами сборных деформирующих инструментов и их прочностью. Выполнены прочностные расчеты деформирующего инструмента для обработки отверстий значительного диаметра со сплошной и дискретной рабочими поверхностями. Численным моделированием, методом конечных элементов получены распределения эквивалентных напряжений в элементах инструмента и контактных напряжений по поверхности контакта твердосплавная вставка-корпус, что позволило проанализировать прочность инструмента под нагрузкой. Определены конструктивные параметры инструмента и приведены алгоритмы последовательности расчета сборных деформирующих элементов (ДЭ). Разработан алгоритм последовательности расчета сборного ДЭ для дискретного протягивания. Предложенная конструкция сборного рабочего элемента позволяет не только улучшить обрабатываемость изделия резания, но и уменьшить расход остродефицитного твердого сплава по сравнению с твердосплавным ДЭ аналогичных размеров на 6 кг. Полученные результаты можно использовать в инженерных расчетах при проектировании сборного инструмента для дискретного деформирования, а также для оценки прочности сборных инструментов, например, фрез, зенкеров, разверток при уточнении внешних нагрузок We developed an algorithm and assessed the strength of prefabricated carbide elements with solid and discrete working surfaces. We obtained dependencies that make it possible to establish a relationship between the design parameters of prefabricated deforming tools and their strength. We performed strength calculations of the deforming tool for machining holes of significant diameter with solid and discrete working surfaces. We obtained the distributions of equivalent stresses in the elements of the tool and contact stresses over the contact surface of the hard-alloy insert - body by numerical modeling, by the finite element method, which made it possible to analyze the strength of the tool under load. We determined the design parameters of the tool and here we give algorithms for the sequence of calculation of prefabricated deforming elements (DE). We developed an algorithm for the sequence of calculating the prefabricated DE for discrete broaching. The proposed design of the prefabricated working element allows not only to improve the machinability of the cutting product but also to reduce the consumption of an acutely deficient hard alloy in comparison with a hard alloy DE of similar dimensions by 6 kg. The results obtained can be used in engineering calculations when designing a prefabricated tool for discrete deformation, as well as for assessing the strength of prefabricated tools, for example, cutters, countersinks, reamers when specifying external loads


2015 ◽  
Vol 769 ◽  
pp. 55-60
Author(s):  
Lubos Hrustinec ◽  
Jozef Sumec ◽  
Jozef Kuzma

In this paper we shall deal with application of analytical and numerical calculation methods in selected geotechnical problem. It is well-known that numerical modeling by Finite Element Method (FEM) is often used for solving complicated engineering problems. FEM is very universal and efficient tool for their solution. In our case a contact task of rigid shallow (circular, rectangular and strip) foundations loaded by centric force, has been solved. The obtained results of vertical normal stresses distributions according to analytical methods and FEM solutions have been analyzed and mutually compared. Results of the calculations have been presented in graphical and tabular form, too.


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