A relationship between tensile strength and loading stress governing the onset of mode I crack propagation obtained via numerical investigations using a bonded particle model

2017 ◽  
Vol 41 (18) ◽  
pp. 1979-1991 ◽  
Author(s):  
Zhenyu Han ◽  
Dion Weatherley ◽  
Ruslan Puscasu
Keyword(s):  
Tensile Strength ◽  
Crack Propagation ◽  
Particle Model ◽  
Mode I ◽  
Mode I Crack ◽  
Numerical Investigations ◽  
Bonded Particle Model

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.

Micro-Strength Analysis of Sand Mold for Casting Based on Bonded-Particle Model

2016 ◽  
Vol 723 ◽  
pp. 316-321
Author(s):  
Fu Xian Zhu ◽  
Zhong De Shan ◽  
Fen Liu
Keyword(s):  
Tensile Strength ◽  
Mass Fraction ◽  
Experimental Results ◽  
Sand Mold ◽  
Strength Analysis ◽  
Particle Model ◽  
Beam Model ◽  
Bonded Particle Model ◽  
Strength Formula ◽  
The Relationship

The micro-strength of sand mold is analyzed based on bonded-particle model (BPM) due to the reason that the strength of sand mold largely influences the final casting properties. In this study, the stress and the strength as well as the stiffness parameters of the binding bridge between the sands are obtained firstly by establishing the equivalent micro-beam model of the binding bridge between the sands. Then, the tensile strength formula of Sand Mold is derived according to the idea packing shape of particle, which is then used for discussing the relationship between the tensile strength with the sand mesh and the mass fraction of binder. At last, the effects of the sand mesh and mass fraction of binder on the tensile strength of the Sand Mold are analyzed quantitatively, which shows the great agreement with the macroscopic experimental results of the sand mold strength.

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
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