Begell House Inc.
International Journal for Multiscale Computational Engineering
JMC
1543-1649
17
5
2019
XFEM SIMULATION OF FATIGUE CRACK GROWTH IN ALUMINUM ZIRCONIA REINFORCED COMPOSITES
469-481
Rahman
Bajmalu Rostami
Materials Testing Institute (IMWF), University of Stuttgart, Stuttgart 70569, Germany
Siegfried
Schmauder
Materials Testing Institute (IMWF), University of Stuttgart, Stuttgart 70569, Germany
The effects of particles as reinforcement on fatigue crack growth behavior of Al 6061/ZrO2 composite material was investigated by the eXtended Finite Element Method (XFEM). This developed methodology represents the entire crack independently, so remeshing is not necessary. Results show that the crack propagation rate increased as volume fraction increased. The same trend was also observed as the particle size decreased in a constant volume fraction. The stress values within the reinforcements were much higher than that in the matrix, and as a consequence, the transferred load to the reinforcing particles slowed down the crack propagation speed by reduction in the stress concentration at the crack tip, and thus enhanced fatigue performance.
A SIMPLIFIED COMPUTATIONAL MODEL FOR MICROPLATES BASED ON A MODIFIED COUPLE STRESS THEORY
483-505
Shengqi
Yang
State Key Laboratory of Structural Analysis for Industrial Equipment, Department of
Engineering Mechanics, Dalian University of Technology, Dalian, 116024, China
Shutian
Liu
State Key Laboratory of Structural Analysis for Industrial Equipment, Department of
Engineering Mechanics, Dalian University of Technology, Dalian, 116024, China
Liyong
Tong
School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney,
Sydney, NSW 2006, Australia
A novel simplified computational model (SCM) is developed for couple stress microplates by using a third-order deformation plate theory and by assuming the rotation about the z-axis is zero in the modified couple stress theory. Analytical solutions are obtained for bending, free vibration, and buckling behaviors of couple stress microplates. Using the present model, a three-node triangular plate element is constructed, in which each node has only seven degrees of freedom. Numerical results of the SCM are compared with those calculated using the complete model (CM) and the original simplified model (SM) available in the literature. The results reveal that the present SCM shows a significant improvement in computational efficiency, while maintaining minimum loss in accuracy, compared with the CM. The computing time used in the CM is 2−5.7 times that used in the SCM.
A NOVEL APPROACH FOR FINDING APPROXIMATE SOLUTIONS OF FRACTIONAL SYSTEMS OF LINEAR PARTIAL DIFFERENTIAL EQUATIONS USING THE FRACTIONAL NATURAL DECOMPOSITION METHOD
507-527
Mahmoud S.
Rawashdeh
Jordan University of Science and Technology, Irbid, Jordan, 22110
Amer H.
Darweesh
Jordan University of Science and Technology, Irbid, Jordan, 22110
In this work, we propose a new approach to find exact solutions to systems of linear fractional partial differential equations (PDEs) using the Fractional Natural Decomposition Method (FNDM). We were be able to find exact solutions for different values of α and β, specifically when α = β = 1, 3/4, 1/2, and 1/4. To the best of our knowledge, we are the first to find such exact solutions for the proposed systems. We employ the FNDM to obtain approximate numerical solutions for two systems of fractional linear PDEs. The FNDM is investigated for these systems of equations and is calculated in the form of power series. The numerical computations in the tables show that our analytical solutions converge very rapidly to the exact solutions.