Fractography of Mode I Crack Propagation in Glass Cloth/Vinylester Composite

2021 ◽  
pp. 164-168
Author(s):  
M. Maeda ◽  
Y. Ma ◽  
K. Inomata ◽  
K. Kitagawa ◽  
Y. Fujii ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Mode I ◽  
Mode I Crack ◽  
Glass Cloth

Fractography of Mode I Crack Propagation in Glass Cloth/Vinylester Composite

2002 ◽  
Vol 10 (1) ◽  
pp. 29-34
Author(s):  
M. Mizoguchi, ◽  
Y. Ma, ◽  
K. Inomata, ◽  
K. Kitagawa, ◽  
Y. Fujii, ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Mode I ◽  
Mode I Crack ◽  
Glass Cloth

scholarly journals Mode I Crack Propagation Experimental Analysis of Adhesive Bonded Joints Comprising Glass Fibre Composite Material under Impact and Constant Amplitude Fatigue Loading

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4380
Author(s):  
Alirio Andres Bautista Villamil ◽  
Juan Pablo Casas Rodriguez ◽  
Alicia Porras Holguin ◽  
Maribel Silva Barrera
Keyword(s):  
Crack Propagation ◽  
Structural Integrity ◽  
Crack Propagation Rate ◽  
Fatigue Loading ◽  
Propagation Rate ◽  
Operating Conditions ◽  
Impact Testing ◽  
Mode I ◽  
Mode I Crack ◽  
Constant Amplitude

The T-90 Calima is a low-wing monoplane aircraft. Its structure is mainly composed of different components of composite materials, which are mainly bonded by using adhesive joints of different thicknesses. The T-90 Calima is a trainer aircraft; thus, adverse operating conditions such as hard landings, which cause impact loads, may affect the structural integrity of aircrafts. As a result, in this study, the mode I crack propagation rate of a typical adhesive joint of the aircraft is estimated under impact and constant amplitude fatigue loading. To this end, effects of adhesive thickness on the mechanical performance of the joint under quasistatic loading conditions, impact and constant amplitude fatigue in double cantilever beam (DCB) specimens are experimentally investigated. Cyclic impact is induced using a drop-weight impact testing machine to obtain the crack propagation rate (da/dN) as a function of the maximum strain energy release rate (GImax) diagram; likewise, this diagram is also obtained under constant amplitude fatigue, and both diagrams are compared to determine the effect of each type of loading on the structural integrity of the joint. Results reveal that the crack propagation rate under impact fatigue is three orders of magnitude greater than that under constant amplitude fatigue.

Molecular dynamics study on atomic elastic stiffness at mode I crack along bi-metal interface

2021 ◽  
Vol 379 (2196) ◽  
pp. 20200124 ◽  
Author(s):  
K. Yashiro
Keyword(s):  
Molecular Dynamics ◽  
Surface Energy ◽  
Crack Propagation ◽  
Metal Structure ◽  
Elastic Stiffness ◽  
Mode I ◽  
Mode I Crack ◽  
Fracture Dynamics ◽  
The Difference ◽  
Deformation Modes

Propagation of mode I crack along bi-metal (001) interfaces of Fe/W, Fe/Ni, Fe/Co and Ti/Mg is simulated by molecular dynamics and discussed with the eigenvalue/vector of the atomic elastic stiffness, B i j a = Δ σ i a / Δ ε j , and surface energy. The crack does not propagate at the interface but in the adjacent phase of smaller surface energy, except in Fe/Ni. The 1st eigenvalue η a (1) , or the solution of B i j a Δ ε j = η a Δ ε i of each atom, clarifies the difference of ‘soft/hard’ of both phases at the onset of crack propagation. In the case of Fe/Ni, the η a (1) of Ni atoms remarkably decreases in the Fe/Ni bi-metal structure, even though Ni has higher η a (1) than Fe at no-load perfect lattices. Thus the rupture occurs in the Ni side even though the Ni has slightly higher (001) surface energy than Fe. Deformation modes at the crack propagation are also visualized by the eigenvector of η a (1)  < 0 unstable atoms. This article is part of the theme issue ‘Fracture dynamics of solid materials: from particles to the globe’.

scholarly journals Discontinuous Dynamics of Mode-I Crack Propagation in Single Crystals

2018 ◽  
Vol 67 (2) ◽  
pp. 222-228
Author(s):  
Tomoaki NIIYAMA ◽  
Tomotsugu SHIMOKAWA ◽  
Taishi FUJIMOTO
Keyword(s):  
Crack Propagation ◽  
Single Crystals ◽  
Mode I ◽  
Mode I Crack

scholarly journals Mode I Crack Propagation under High Cyclic Loading in 316L Stainless Steel

2014 ◽  
Vol 3 ◽  
pp. 1197-1203 ◽  
Author(s):  
W. Zhang ◽  
S. Pommier ◽  
F. Curtit ◽  
G. Léopold ◽  
S. Courtin
Keyword(s):  
Stainless Steel ◽  
Cyclic Loading ◽  
Crack Propagation ◽  
316L Stainless Steel ◽  
Mode I ◽  
Mode I Crack

scholarly journals Using a penalty term to deal with spurious oscillations in second gradient finite elements

2018 ◽  
Vol 28 (3) ◽  
pp. 346-366
Author(s):  
Marc Soufflet ◽  
Gwendal Jouan ◽  
Panagiotis Kotronis ◽  
Frédéric Collin
Keyword(s):  
Crack Propagation ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Constitutive Law ◽  
Mode I ◽  
Mode I Crack ◽  
Internal Length ◽  
Penalty Term ◽  
Second Gradient ◽  
Spurious Oscillations

It is well known that it is necessary to introduce a length scale parameter in a continuum damage mechanics model to correctly simulate strain localization. The second gradient model, a special case of kinematically enriched continua, considers an internal length parameter by taking into account the second-order derivatives of the displacements in the virtual power principle. In this paper, we show that the original second gradient finite element of Chambon and co-workers can present spurious oscillations, especially for mode I crack propagation problems. After providing the plane stress second gradient constitutive law, we propose to add a penalty term in the original formulation in order to improve numerical convergence and to avoid spurious oscillations in the local variables distributions. Two numerical examples using classical damage mechanics laws, a three-point reinforced concrete beam and a trapezoidal notched specimen are used to test the performance of the formulation. Parametrical studies are also shown on the influence of the penalty parameter. The problem of unrealistic damage spreading for damage values close to 1, occurring often in mode I crack propagation problems, is finally discussed.

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