scholarly journals Investigation of the mechanical performance of fiber-modified ceramic composites using finite element method

2019 ◽  
Vol 13 (3) ◽  
pp. 173-179
Author(s):  
Majid Ahmadi ◽  
Seyed Hadi Seyedin ◽  
Seyed Vahid Seyedin
Keyword(s):  
Experimental Data ◽  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Performance ◽  
Porous Ceramic ◽  
Ceramic Composites ◽  
Material Structure ◽  
Composition Material ◽  
Starting Point ◽  
Element Method

Ceramic materials are widely used in impact safekeeping systems. Ceramic is a heterogeneous material; its characteristics depend considerably both on specifications of its ingredients and the material structure completely. The finite element method (FEM) can be a useful tool for strength computation of these materials. In this paper, the mechanical properties of the ceramic composites are investigated, and the mechanical performance modeling of fiber-fortified ceramic matrix composites (CMC) is expressed by the instance of aluminum oxide fibers in a matrix composite based on alumina. The starting point of the modeling is an infrastructure (primary cell) that contains a micromechanical size, the statistical analysis characteristics of the matrix, fiber-matrix interface, fiber, and their reciprocal influences. The numeral assessment of the model is done using the FEM. The numerical results of composite elastic modulus were computed based on the amount of the added fibers and the porosity was evaluated for empirical data of samples with a similar composition. Various scanning electron microscope (SEM) images were used for each sample to specify the porosity. Also, the unit cell method presumed that the porous ceramic substance is manufactured from an array of fundamental units, each with the same composition, material characteristic, and cell geometry. The results showed that when the material consists of different pores and fibers, the amount of Young’s modulus reduces with the increment of porosity. The linear correlation model of elasticity versus porosity value from experimental data was derived by MATLAB curve fitting. The experimental data from the mechanical test and numerical values were in good agreement.

scholarly journals Modeling of the mechanical behavior of fiber-reinforced ceramic composites using finite element method (FEM)

2014 ◽  
Vol 46 (3) ◽  
pp. 385-390 ◽  
Author(s):  
M.M. Dimitrijevic ◽  
N. Tomic ◽  
B. Medjo ◽  
R. Jancic-Heinemann ◽  
M. Rakin ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Behavior ◽  
Ceramic Matrix Composites ◽  
Ceramic Composites ◽  
Elementary Cell ◽  
Fiber Reinforced ◽  
Starting Point ◽  
Fiber Matrix ◽  
Element Method

Modeling of the mechanical behavior of fiber-reinforced ceramic matrix composites (CMC) is presented by the example of Al2O3 fibers in an alumina based matrix. The starting point of the modeling is a substructure (elementary cell) which includes on a micromechanical scale the statistical properties of the fiber, matrix and fiber-matrix interface and their interactions. The numerical evaluation of the model is accomplished by means of the finite element method. The numerical results of calculating the elastic modulus of the composite dependance on the quantity of the fibers added and porosity was compared to experimental values of specimens having the same composition.

Analysis and Optimization of Metal to Composite Joints for Marine Structures

2014 ◽  
Vol 556-562 ◽  
pp. 91-95
Author(s):  
Xiao Wen Li ◽  
Ping Li ◽  
Zhuang Lin ◽  
Dong Mei Yang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Performance ◽  
Optimization Method ◽  
Additional Stress ◽  
Marine Structures ◽  
Hybrid Joint ◽  
Composite Joint ◽  
Numerical Predictions ◽  
Element Method

Composite to metal joints as important components of marine structures are gradually found in the marine industry. The purpose of this study is to investigate mechanical performance and optimization method of the composite sandwich to steel joints. The main emphasis was placed on the mechanical properties of a hybrid joint between a sandwich glass fibre reinforced plastic superstructure and a steel main hull. Based on the experiments of a base joint, a new finite element method was used to analyze a series of joints. The optimized joint was presented due to reducing weight and enhancing the mechanical performance. The numerical predictions of the base hybrid joint showed a very good correlation with the experiment results, which validated the reliability of the new finite element method. The strength of the optimized joint was also evaluated by finite element method. The result is similar to the base joint. And there is no additional stress concentration in weak parts. The optimized joint has 30% lower weight than the base joint, and the stress is only about 5% ~ 56% of the base one. The results of the present work imply that the change of geometric parameter is an effective method to improve the performance of the metal to composite joint.

Finite Element Calculation of Sintering Deformation Using Limited Experimental Data

2008 ◽  
Vol 606 ◽  
pp. 103-118 ◽  
Author(s):  
Jing Zhe Pan ◽  
Ruo Yu Huang
Keyword(s):  
Experimental Data ◽  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Ceramic Powder ◽  
Material Model ◽  
Element Analysis ◽  
Ceramic Components ◽  
On Line ◽  
Element Method

Predicting the sintering deformation of ceramic powder compacts is very important to manufactures of ceramic components. In theory the finite element method can be used to calculate the sintering deformation. In practice the method has not been used very often by the industry for a very simple reason – it is more expensive to obtain the material data required in a finite element analysis than it is to develop a product through trial and error. A finite element analysis of sintering deformation requires the shear and bulk viscosities of the powder compact. The viscosities are strong functions of temperature, density and grain-size, all of which change dramatically in the sintering process. There are two ways to establish the dependence of the viscosities on the microstructure: (a) by using a material model and (b) by fitting the experimental data. The materials models differ from each other widely and it can be difficult to know which one to use. On the other hand, obtaining fitting functions is very time consuming. To overcome this difficulty, Pan and his co-workers developed a reduced finite element method (Kiani et. al. J. Eur. Ceram. Soc., 2007, 27, 2377-2383; Huang and Pan, J. Eur. Ceram. Soc., available on line, 2008) which does not require the viscosities; rather the densification data (density as function of time) is used to predict sintering deformation. This paper provides an overview of the reduced method and a series of case studies.

Coupling Finite Element Method and Perturbation Techniques for Non Linear Vibrations of Plates

1999 ◽  
Author(s):  
L. Azrar ◽  
R. Benamar ◽  
M. Potier-Ferry
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computation Time ◽  
Free Vibrations ◽  
Perturbation Techniques ◽  
Structural Problems ◽  
Starting Point ◽  
Linear Vibrations ◽  
The Right ◽  
Element Method

Abstract The effectiveness of the coupling of the perturbation techniques and the finite element method has been demonstrated using a method called Asymptotic-Numerical Method (ANM). This concept eliminates the major difficulties of the classical perturbation methods namely the complexity of the right hand sides and the limitation of the validity of the solution obtained. In this paper we present the development of this method and its applicability for large amplitudes free vibrations of plates. The displacement and the frequency are expanded into power series with respect to a control parameter. The nonlinear governing equation is transformed into a sequence of linear problems having the same stiffness matrix. Needing one matrix inversion, a large number of terms can be computed with a small computation time. Taking the starting point in the zone of validity, the method is reapplied in order to determine a further part of the nonlinear solution. In order to increase the zone of validity, the Pade approximants are incorporated. Iterations of this method lead to a powerful incremental method. Numerical tests for large amplitudes free vibrations of plates with various shapes and boundary conditions are reported. Recent improvements in the basic ANM algorithm as well as applications to various structural problems are added in order to exhibit the effectiveness and the applicability of this method.

A Case Study of Conceptual Design Analysis of Stove Brackets Using Finite Element Method

2008 ◽  
Author(s):  
Diego Va´zquez ◽  
Hugo Medelli´n ◽  
Antonio Ca´rdenas ◽  
Alonso de la Garza
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Experimental Analysis ◽  
Mechanical Performance ◽  
Fem Simulation ◽  
Production Costs ◽  
The Finite Element Method ◽  
Design Change ◽  
Element Method

Advanced engineering techniques for analysis are modern tools used for companies to enhance the design and manufacturing cycles of new or existing products. Finite element method has become one of the most used tools in the design process of products. This paper presents a case study regarding a design change of the brackets that support the gas jet in stoves. Using the finite element method, the mechanical performance of the existing brackets is compared with the performance of the new proposed bracket. This comparison is used to evaluate the feasibility of carrying out the design change. The benefit of the new design is a reduction of materials, production costs and production times. Experimental analysis of the materials and the validation of the finite element solutions were also performed. The results of the experimental analysis and FEM simulation are discussed and presented. Finally, the performance of the existing and the new brackets under several load cases is compared and the results suggest that the product design change is feasible.

Numerical Analysis of Stress States for Graphitic Cast Iron Structures

2014 ◽  
Vol 611 ◽  
pp. 252-255 ◽  
Author(s):  
Jan Vavro ◽  
Ján Vavro ◽  
Petra Kováčiková ◽  
Peter Kopas ◽  
Marián Handrik ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cast Iron ◽  
Numerical Analysis ◽  
Ductile Cast Iron ◽  
Material Structure ◽  
The Finite Element Method ◽  
The Matrix ◽  
Stress States ◽  
Element Method

The presented work is focused on the analysis of stress distribution around the graphitic particles in microstructure of ductile cast iron with the spheroidal shape of graphite (SGCI) and grey cast iron with the lamellar shape of graphite (LGCI). The analysis was made with help of the finite element method in the software system ADINA.v.8.6.2. On the basis of the real structure, the finite element method was used for creation of the model which was subsequently used for calculation of the distribution of stress in the material structure. The input data for numerical analysis were obtained on the basis of evaluation of the structure with help of image analysis. The numerical analysis proved that graphitic particles in the matrix cause the accumulation of stress and the distribution of given stress depends on the shape of the graphitic particles.

Simulation of Thermo Mechanical Behavior of Structures by the Numerical Resolution of Direct Problem

2011 ◽  
Vol 61 ◽  
pp. 85-93
Author(s):  
B. Aouragh ◽  
J. Chaoufi ◽  
H. Fatmaoui ◽  
Jean Christophe Dupré ◽  
Claude Vallée ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Infrared Thermography ◽  
Direct Problem ◽  
The Finite Element Method ◽  
Numerical Techniques ◽  
Numerical Resolution ◽  
Starting Point ◽  
Experimental And Numerical Modeling ◽  
Element Method

The aim of our study is to develop an approach to both experimental and numerical modeling to the thermal behavior of a material by identifying these thermal parameters. The theoretical part is based on the finite element method which is a starting point to solve a two-dimensional inverse heat. The experimental measurements are performed by infrared thermography. All these experimental and numerical techniques give this method properties valued in the industrial world as the non-intrusive measurements and real-time calculations. For this, we have supported a system of equations and the temperature field, so before starting the inverse problem, we addressed the direct problem by finite element method that has been compared to measures experimental infrared thermography well to check the validity of equations, so it’s the purpose of this work.

scholarly journals The issues of designing of construction features of the internal combustion cam engine

2017 ◽  
Vol 171 (4) ◽  
pp. 259-264
Author(s):  
Tomasz BOROWCZYK ◽  
Mikołaj SPADŁO
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Combustion ◽  
Constant Volume ◽  
The Finite Element Method ◽  
Starting Point ◽  
Piston Mechanism ◽  
Crank Mechanism ◽  
Element Method

On the pages of the article described cam-piston mechanism developed as an alternative to piston crank mechanism. The main feature of this mechanism is that the piston is dwell in the TDC by the 30°CA and thus allows combustion of the fuel in constant volume. Authors presented the process of designing an analytical cam. The starting point for the calculation was the displacement of piston graph and the limits of acceleration and velocity values obtained. The results of strength calculations of the cam with regard to fatigue problems are also presented. Calculations were carried out in order to reduce the weight of the cam. For this purpose, the Finite Element Method was used.

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