Fatigue Crack Initiation and Propagation in Lotus-Type Porous Copper

Seki, Hiroya; Tane, Masakazu; Nakajima, Hideo

doi:10.2320/matertrans.mra2007623

Cited by 13 publications

(8 citation statements)

References 22 publications

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“…When studying the case of pores distribution in longitudinal direction, more homogenous stress and deformation field has been found around the longitudinal pores. This finding is also in agreement with the experimental work published in [10] where authors have pointed out that the stress concentration around the pores is in the case of longitudinal pores lower if compare to the transversal pore distribution. Therefore, the crack initiation and crack propagation period for longitudinal pore distribution has not been studying in the framework of this paper.…”

Section: Crack Initiation and Propagation Period For Pores Distributisupporting

confidence: 93%

“…[9]. The porosity of lotus metals is usually lower than 70%, which is lower if compare to some conventional porous metals where porosity is often higher than 70% [10]. Moreover, pores of lotus-type metals are cylindrical, where the length of pores is usually large if compare to pore diameter ( Fig.…”

Section: Introductionmentioning

confidence: 99%

“…these results cannot be used for lotus-type porous materials due to different pore shapes and their orientations. Seki et al [10,14,15] have been studied the fatigue behaviour of cooper and magnesium lotus-type porous structures where the effect of porosity, anisotropic pore structure, and pore size distribution have been taken into account. Their experimental research has shown that for the fatigue loading parallel to the longitudinal axis of pores the stress field in the matrix is homogeneous and slip bands appear all over the specimen surface.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Fatigue crack initiation and propagation in lotus-type porous material

Glodež¹,

Dervarič²,

Kramberger³

et al. 2015

Frattura Ed Integrità Strutturale

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The investigation of fatigue strength of lotus-type structure with nodular cast iron as a base material using computational model is analysed in present study. The irregular pores distribution in transversal and longitudinal direction, regarding the external loading, is considered in the computational models. The complete fatigue process of analyzed porous structure is then divided into the crack initiation (N i ) and crack propagation (Np) period where the total fatigue life (N) is defined as: N = Ni + Np. The crack initiation period is determined using strain life approach where elastic-plastic numerical analysis is performed to obtain the total strain amplitude in the critical stress fields around the pores. The simplified universal slope method is then used to determine the number of stress cycles, N i , required for formation of initial cracks. The number of stress cycles, N p , required for crack propagation from initial to the critical crack length is also numerically determined using finite element (FE) models, in the frame of Abaqus computation FEM code. The maximum tensile stress (MTS) criterion is considered when analyzing the crack path inside the porous structure. The performed computational analyses show that stress concentrations around individual pores are higher when external loading is acting in transversal direction in respect to the pore distribution. Therefore, further computational analyses regarding crack initiation and crack propagation period have been done only for pores distribution in transversal direction.

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Section: Crack Initiation and Propagation Period For Pores Distributisupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fatigue crack initiation and propagation in lotus-type porous material

Glodež¹,

Dervarič²,

Kramberger³

et al. 2015

Frattura Ed Integrità Strutturale

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“…In particular, these metals exhibit superior mechanical properties to the conventional porous metals, which have nearly spherical, isotropic pore shape. [7,8] The use of pressurized gas such as hydrogen, nitrogen, and oxygen was required for the fabrication process of lotus-type porous metal with unidirectional elongated pores. [9][10][11] Especially, hydrogen was the most useful to fabricate the lotus metals.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Lotus-Type Porous Aluminum through Thermal Decomposition Method

Kim

Park

Nakajima

2009

Metall Mater Trans A

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Lotus-type porous aluminum with cylindrical pores was fabricated by unidirectional solidification through thermal decomposition of calcium hydroxide, sodium bicarbonate, or titanium hydride. The pore-forming gas decomposed from calcium hydroxide, sodium bicarbonate, and titanium hydride is identified as hydrogen. The elongated pores are evolved due to the solubility gap between liquid and solid when the melt dissolving hydrogen is solidified unidirectionally. The porosity of lotus aluminum is as high as 20 pct despite the type of the compounds. The pore size decreases and the pore density increases with increasing amount of calcium hydroxide, which is explained by an increase in the number of pore nucleation sites. The porosity and pore size in lotus aluminum fabricated using calcium hydroxide decrease with increasing argon pressure, which is explained by Boyle's law. It is suggested that this fabrication method is simple and safe, which makes it superior to the conventional technique using high-pressure hydrogen gas.

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“…[4]. The porosity of lotus materials is usually lower than porosity of some conventional porous metals [5].…”

Section: Introductionmentioning

confidence: 99%

Computational simulation of biaxial fatigue behaviour of lotus-type porous material

Kramberger¹,

Šori²,

Sraml³

et al. 2016

Frattura Ed Integrità Strutturale

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A computational simulation of low-cycle fatigue behaviour of lotus-type porous material, subjected to biaxial in-phase loading cycles is presented in this paper. Fatigue properties of porous materials are less frequently published in the literature. This paper evaluates computational analyses, where different pore distribution and biaxial loading conditions in relation to the pore orientations is considered in each simulation. The fatigue analysis is performed by using a damage initiation and evolution law based on the inelastic strain energy. The computational results are subjected to the appropriate statistical analysis, because of different pore topology a different fatigue lives are obtained on the same loading level. Results of computational simulations show also a qualitative understanding of porosity influence on low-cycle fatigue failures of lotus-type porous material under biaxial loading conditions

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Fatigue Crack Initiation and Propagation in Lotus-Type Porous Copper

Cited by 13 publications

References 22 publications

Fatigue crack initiation and propagation in lotus-type porous material

Fatigue crack initiation and propagation in lotus-type porous material

Fabrication of Lotus-Type Porous Aluminum through Thermal Decomposition Method

Computational simulation of biaxial fatigue behaviour of lotus-type porous material

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