• Title, Summary, Keyword: Minimum Strain Energy Density Criterion

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Ambiguity of Minimum Strain Energy Density Criterion and Maximum Minimum Strain Energy Density Criterion (최소 변형에너지 밀도 기준의 모호성과 최대 극소 변형에너지 밀도 기준)

  • Gu, Jae-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.7
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    • pp.1155-1162
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    • 2001
  • Sihs minimum strain energy density criterion(SED) often used in the mixed mode problem has the ambiguity of the choice of minimum values. In this paper, as the method to solve the problem of SED, maximum minimum strain energy density criterion is proposed that the crack propagates in the direction of having the maximum among the minimum values of modified strain energy density factor(MS), i.e., sign($\sigma$(sub)$\theta$).Smin.

Mixed mode I/II fracture criterion to anticipate behavior of the orthotropic materials

  • Farid, Hannaneh Manafi;Fakoor, Mahdi
    • Steel and Composite Structures
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    • v.34 no.5
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    • pp.671-679
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    • 2020
  • The new energy-based criterion, named Reinforcement Strain Energy Density (ReiSED), is proposed to investigate the fracture behavior of the cracked orthotropic materials in which the crack is embedded in the matrix along the fibers. ReiSED is an extension of the well-known minimum strain energy density criterion. The concept of the reinforced isotropic solid as an advantageous model is the basis of the proposed mixed-mode I/II criterion. This model introduces fibers as reinforcements of the isotropic matrix in orthotropic materials. The effects of fibers are qualified by defining reinforcement coefficients at tension and shear modes. These coefficients, called Reduced Stress (ReSt), provide the possibility of encompassing the fiber fraction in a fracture criterion for the first time. Comparing ReiSED fracture limit curve with experimental data proves the high efficiency of this criterion to predict the fracture behavior of orthotropic materials.

A Study on Mixed Mode Crack Initiation under Static Loading Condition

  • Koo, Jea-Mean
    • International Journal of Safety
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    • v.2 no.1
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    • pp.1-6
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    • 2003
  • In this paper, several different fracture criteria using the Eftis and Subramanian's stress solutions [1] are compared with the printed experimental results under different loading conditions. The analytical results of using the solution with non-singular term show better than without non-singular in comparison with the experimental data. And maximum tangential stress criterion (MTS) and maximum tangential strain energy density criterion (MTSE) can get useful results for several loading conditions.

Study on Crack Propagation of Concrete beam under Mixed-Mode Loading by Minimum Strain Energy Density Failure Criterion (최소 변형 에너지 밀도 기준에 의한 콘크리트 보의 균열전파에 관한 연구)

  • 진치섭;이영호;신동익;오정민
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.529-534
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    • 1998
  • To find out an adequate failure criterion in two-dimensional linear elastic crack problems, finite element programs, SED, which determine stress intensity factors $K_I, K_{II}$, crack angle and peak load by the minimum strain energy density failure criterion were developed. In this program, the conventional quadratic isoparametric elements were used in all regions except the crack tip zone where triangular singular elements with 6 nodes were used. The results of SED were compared with the results of those which followed by the maximum circumferential tensile stress criteria and those by the maximum energy release rate criteria and those by Jenq and Shah`s experiments of the same geometry and material properties. The maximum energy release rate criteria were better close to those of the Jenq and Shah`s experiments than the maximum circumferential tensile stress criteria and the minimum strain energy density criteria.

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An Application of Minimum Strain Energy Density Criterion in Mixed Mode Fatigue Problem (혼합모드 피로문제에서의 최소 변형에너지 밀도기준의 적용)

  • Shim, Kyu-Seok;Koo, Jae-Mean
    • Journal of the Korean Society of Safety
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    • v.17 no.2
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    • pp.1-7
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    • 2002
  • In this paper, the maximum minimum strain energy density criterion was applied to the mixed mode fatigue test of A5052 H34 alloy. In this study result we can have seen that the authors stress intensity factor for the finite width specimen and method of determining testing load, based on the plastic zone size and the limited maximum stress intensity factor by ASTM STANDARD E-647-95, is useful.

A Study on the Initial Crack Curving Angle of Isotropic/Orthotropic Bimaterial

  • Hawong, Jai-Sug;Shin, Dong-Chul;Lee, Ouk-Sub
    • Journal of Mechanical Science and Technology
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    • v.16 no.12
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    • pp.1594-1603
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    • 2002
  • In this paper, when the initial propagation angle of a branched crack is calculated from the maximum tangential stress criterion (MTSC) and the minimum strain energy density criterion (MSEDC), it is essential that you use stress components in which higher order terms are considered and stress components at the position in a distance 0.005㎜ from the crack tip (=r). When an interfacial crack propagates along the interface at a constant velocity, the initial propagation angles of the branched crack are similar. to the mode mixities (phase angle) and the theoretical values obtained from MTSC and MSEDC. The initial propagation angle of the branched crack depends considerably on the stress intensity factor K$_2$.

A Study on the Interfacial Crack Propagation Criterion for Two Dissimilar Isotropic Bimaterial by the Static Photoelastic Experimental Hybrid Method (정적 광탄성 실험 하이브리드 법에 의한 두 상이한 등방성 이종재료의 계면균열전파 기준에 관한 연구)

  • Tche, Konstantin;Hawong, Jai-Sug;Shin, Dong-Chul;Nam, Sung-Su;Nam, Jeong-Hwan
    • Proceedings of the KSME Conference
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    • pp.1216-1221
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    • 2003
  • The specimen materials used in this research is bimaterial. The static photoelastic experiment was applied to them. And then the specimens used in photoelastic experiment were fractured under static load. The static photoelastic hybrid method was introduced and it's validity had been assured. The static photoelastic hybrid method was applied to the Minimum Strain Energy Density Criterion, the Maximum Tangential Stress Criterion and Mode Mixity. Crack propagation criterion by the static photoelastic hybrid method was introduced and it was applied to the above various failure theories. Comparing the experimental initial angle of crack propagation with the theoretical initial angle of crack propagation from the various failure criterions. And then the optimal crack propagation criterion was suggested and it's validity was assured.

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Application of the Static Photoelastic Experimental Hybrid Method to the Crack Propagation Criterion for Isotropic Materials (등방성체의 균열전파 기준에 정적 광탄성 실험 하이브리드 법 적용)

  • Shin Dong-Chul;Hawong Jai-Sug;Nam Sung-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.8
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    • pp.1229-1236
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    • 2004
  • The specimen materials used in this research are isotropic epoxy resins. The static photoelastic experiment was applied to them. And then the specimens used in photoelastic experiment were fractured under static load. The static photoelastic experimental hybrid method was introduced and its validity had been assured. Crack propagation criterion used the stress components, which are considered the higher order terms, obtained from the static photoelastic experimental hybrid method was introduced and it was applied to the minimum strain energy density criterion, the maximum tangential stress criterion and mode mixity. Comparing the actual initial angle of crack propagation with the theoretical initial angle of crack propagation obtained from the above failure criterions, the validities of the above two criterions are assured and the optimal distance (r) from the crack-tip is 0.01mm in order to get the initial angle of crack propagation of isotropic epoxy resin.

A Study on the Crack Propagation Criterion of Orthotropic Material by the Static Photoelastic Experimental Hybrid Method (정적 광탄성 실험 하이브리드법에 의한 직교이방성체의 균열전파 기준에 관한 연구)

  • Shin, Dong-Chul;Hawong, Jai-Sug;Nam, Sung-Su;Kwon, O-Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.11
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    • pp.1799-1806
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    • 2004
  • The static photoelastic experiment was applied to orthotropic materials. And then the specimens used in photoelastic experiment were fractured under static load. The static photoelastic experimental hybrid method for orthotropic material was introduced and its validity had been assured. Crack propagation criterion used the stress components, which are considered the higher order terms, obtained from the static photoelastic experimental hybrid method was introduced and it was applied to the minimum strain energy density criterion, the maximum tangential stress criterion and mode mixity. Comparing the actual initial angle of crack propagation with the theoretical initial angle of crack propagation obtained from the above failure criterions, the validities of the above two criterions are assured and the optimal distance (${\gamma}$) from the crack-tip is 0.01mm in order to get the initial angle of crack propagation of orthotropic material(C.F.E.C.).

On the mixed-mode crack propagation in FGMs plates: comparison of different criteria

  • Nabil, Benamara;Abdelkader, Boulenouar;Miloud, Aminallah;Noureddine, Benseddiq
    • Structural Engineering and Mechanics
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    • v.61 no.3
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    • pp.371-379
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    • 2017
  • Modelling of a crack propagating through a finite element mesh under mixed mode conditions is of prime importance in fracture mechanics. In this paper, two crack growth criteria and the respective crack paths prediction in functionally graded materials (FGM) are compared. The maximum tangential stress criterion (${\sigma}_{\theta}-criterion$) and the minimum strain energy density criterion (S-criterion) are investigated using advanced finite element technique. Using Ansys Parametric Design Language (APDL), the variation continues in the material properties are incorporated into the model by specifying the material parameters at the centroid of each finite element. In this paper, the displacement extrapolation technique (DET) proposed for homogeneous materials is modified and investigated, to obtain the stress intensity factors (SIFs) at crack-tip in FGMs. Several examples are modeled to evaluate the accuracy and effectiveness of the combined procedure. The effect of the defects on the crack propagation in FGMs was highlighted.