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Homogenization of plates with parallel cracks

Holek Mateusz, Fedeliński Piotr

Journal of Applied Mathematics and Computational Mechanics

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2020

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Vol. 19, nr 1

31--41

EN

The paper presents an analysis of effective elastic properties of plates with parallel cracks using the finite element method (FEM) and the boundary element method (BEM). Rectangular plates with parallel or inclined cracks to the edges of plates were considered. Different distances between cracks and different angles of cracks were studied. The displacement and traction boundary conditions were applied and their influence on the accuracy of overall properties of cracked material was analysed. The results obtained by the FEM and the BEM were compared.

2

Proposal of the hybrid solution to determining the selected fracture parameters for SEN(B) specimens dominated by plane strain

Graba M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2017

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Vol. 65, nr 4

523--532

EN

In the paper, new hybrid (numerical-analytical) methods to calculate the J-integral, the CTOD, and the load line displacement are presented. The proposed solutions are based on FEM calculations which were done for SEN(B) specimens dominated by plane strain condition. The paper includes the verification of the existing limit load solution for SEN(B) specimen with proposal of the new analytical formulae, which were used for building hybrid equations for determining three selected fracture mechanics parameters.

3

Multiscale simulation of major crack/minor cracks interplay with the corrected XFEM

Liu G., Zhou D., Bao Y., Ma J., Han Z.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 2

410--418

EN

The present work aims at saving computational cost of multiscale simulation on major crack/minor crack interaction problems. The multiscale extended finite element method (MsXFEM) used for the numerical simulation is developed on multiscale projection technique which enables different scale decomposition, and transition of field variables between different scales. Both macroscale and microscale problems are solved independently and alternatively, in the framework of XFEM. The improvement made in this paper is to employ corrected XFEM on the macroscale level, so that a more accurate boundary condition can be obtained for the microscale problem. The modification leads to a reduced necessary microscale domain size, meanwhile a solution of higher accuracy and enhanced convergence rate can be achieved. The numerical examples of minor cracks near a major one are studied, which show that the effect of minor cracks on major crack can be efficiently captured.

4

Investigation on fatigue behaviour of load-carrying fillet welded joints based on mix-mode crack propagation analysis

Zong L., Shi G., Wang Y. Q., Yan J. B., Ding Y.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 3

677--686

EN

The fatigue behaviour of the load-carrying fillet welded joints was investigated by experimental and numerical approach in this paper. 26 load-carrying cruciform fillet welded joints involving 8 stress levels were tested and the S–N curves of 95% survival probability in terms of toe failure and root failure were established separately. The test results also demonstrate that the design curves of Eurocode3 are not suitable for this batch of specimens. In the following numerical simulations, three types of initial crack assumption were analysed by 3D mix-mode fatigue crack propagation analysis according to experimental observation. All the possible crack growth routes were simulated well. However, the single crack assumptions cannot form satisfactory simulations on fatigue lives with enough safety stock. Therefore, multi-crack analysis was conducted based on the combined data in terms of both toe failure and root failure. It is found that multi-crack analysis with 0.5 mm weld toe initial line crack and 0.1 mm weld root initial line crack can provide appropriate prediction. The findings can be beneficial for the fatigue assessment of load-carrying fillet welded joints fabricated by the normal welding technique in China and offer some references for the fatigue assessment of structural details with different possible failure modes.