Finite element contact, stress and strain analysis of a composite fibre-matrix micro system subjected to ball indentation

K. Váradi, Z. Neder, K. Friedrich, J. Flock

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

The presented FE contact technique is applied to the problem of a steel ball indented into a composite material consisting of unidirectional continuous carbon fibres in a polyetheretherketone matrix. Indentation was carried out with fibre orientations either normal (N) or parallel (P) to the contact surface at fiber volume fraction 44%. The FE contact stress analysis of a fibre-matrix micro structure has some strong limitations. If FE micro models are used, only a very small (for example 0.1 × 0.1 mm) 3D segment can be modelled while the number of degrees of freedom (DOF) is immediately in the range of 100 000. If the anisotropic numerical models are used, there are no size limitations but the results can not describe the stress and strain states of a real fibre/matrix micro structure. The FE contact analysis involves both an anisotropic (homogeneous) macro and (inhomogeneous) micro contact analysis, following an approximate displacement coupling technique. This technique considers only the displacements along the coupled surfaces. The coupled solution provides a more realistic elastic deformation, stress and strain results of the composite micro system in the vicinity of the contact area, and at the same time the effect o the macro system is also incorporated. The FE contact results show the location and the distribution of the subsurface stresses and strains. For N fibre orientation there is a high shear stress region below the surface, from where the fibre/matrix interfacial failure initiates before propagation to the surface. These results are in good agreement with experimental results published in the open literature. In case of P fibre orientation the matrix is subjected to local plastic deformation while the characteristic deformation of the fibre is bending.

Original languageEnglish
Title of host publicationProc. ASME International Mechanical Engineering Congress and Exposition, Dallas, November 1997
PublisherASME
Pages26-36
Number of pages11
Publication statusPublished - 1998

Fingerprint

Indentation
Fiber reinforced materials
Fibers
Composite materials
Macros
Microstructure
Steel
Elastic deformation
Stress analysis
Carbon fibers
Shear stress
Numerical models
Volume fraction
Plastic deformation

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Váradi, K., Neder, Z., Friedrich, K., & Flock, J. (1998). Finite element contact, stress and strain analysis of a composite fibre-matrix micro system subjected to ball indentation. In Proc. ASME International Mechanical Engineering Congress and Exposition, Dallas, November 1997 (pp. 26-36). ASME.

Finite element contact, stress and strain analysis of a composite fibre-matrix micro system subjected to ball indentation. / Váradi, K.; Neder, Z.; Friedrich, K.; Flock, J.

Proc. ASME International Mechanical Engineering Congress and Exposition, Dallas, November 1997. ASME, 1998. p. 26-36.

Research output: Chapter in Book/Report/Conference proceedingChapter

Váradi, K, Neder, Z, Friedrich, K & Flock, J 1998, Finite element contact, stress and strain analysis of a composite fibre-matrix micro system subjected to ball indentation. in Proc. ASME International Mechanical Engineering Congress and Exposition, Dallas, November 1997. ASME, pp. 26-36.
Váradi K, Neder Z, Friedrich K, Flock J. Finite element contact, stress and strain analysis of a composite fibre-matrix micro system subjected to ball indentation. In Proc. ASME International Mechanical Engineering Congress and Exposition, Dallas, November 1997. ASME. 1998. p. 26-36
Váradi, K. ; Neder, Z. ; Friedrich, K. ; Flock, J. / Finite element contact, stress and strain analysis of a composite fibre-matrix micro system subjected to ball indentation. Proc. ASME International Mechanical Engineering Congress and Exposition, Dallas, November 1997. ASME, 1998. pp. 26-36
@inbook{7800fd6565fd452f9398e5496c987024,
title = "Finite element contact, stress and strain analysis of a composite fibre-matrix micro system subjected to ball indentation",
abstract = "The presented FE contact technique is applied to the problem of a steel ball indented into a composite material consisting of unidirectional continuous carbon fibres in a polyetheretherketone matrix. Indentation was carried out with fibre orientations either normal (N) or parallel (P) to the contact surface at fiber volume fraction 44{\%}. The FE contact stress analysis of a fibre-matrix micro structure has some strong limitations. If FE micro models are used, only a very small (for example 0.1 × 0.1 mm) 3D segment can be modelled while the number of degrees of freedom (DOF) is immediately in the range of 100 000. If the anisotropic numerical models are used, there are no size limitations but the results can not describe the stress and strain states of a real fibre/matrix micro structure. The FE contact analysis involves both an anisotropic (homogeneous) macro and (inhomogeneous) micro contact analysis, following an approximate displacement coupling technique. This technique considers only the displacements along the coupled surfaces. The coupled solution provides a more realistic elastic deformation, stress and strain results of the composite micro system in the vicinity of the contact area, and at the same time the effect o the macro system is also incorporated. The FE contact results show the location and the distribution of the subsurface stresses and strains. For N fibre orientation there is a high shear stress region below the surface, from where the fibre/matrix interfacial failure initiates before propagation to the surface. These results are in good agreement with experimental results published in the open literature. In case of P fibre orientation the matrix is subjected to local plastic deformation while the characteristic deformation of the fibre is bending.",
author = "K. V{\'a}radi and Z. Neder and K. Friedrich and J. Flock",
year = "1998",
language = "English",
pages = "26--36",
booktitle = "Proc. ASME International Mechanical Engineering Congress and Exposition, Dallas, November 1997",
publisher = "ASME",

}

TY - CHAP

T1 - Finite element contact, stress and strain analysis of a composite fibre-matrix micro system subjected to ball indentation

AU - Váradi, K.

AU - Neder, Z.

AU - Friedrich, K.

AU - Flock, J.

PY - 1998

Y1 - 1998

N2 - The presented FE contact technique is applied to the problem of a steel ball indented into a composite material consisting of unidirectional continuous carbon fibres in a polyetheretherketone matrix. Indentation was carried out with fibre orientations either normal (N) or parallel (P) to the contact surface at fiber volume fraction 44%. The FE contact stress analysis of a fibre-matrix micro structure has some strong limitations. If FE micro models are used, only a very small (for example 0.1 × 0.1 mm) 3D segment can be modelled while the number of degrees of freedom (DOF) is immediately in the range of 100 000. If the anisotropic numerical models are used, there are no size limitations but the results can not describe the stress and strain states of a real fibre/matrix micro structure. The FE contact analysis involves both an anisotropic (homogeneous) macro and (inhomogeneous) micro contact analysis, following an approximate displacement coupling technique. This technique considers only the displacements along the coupled surfaces. The coupled solution provides a more realistic elastic deformation, stress and strain results of the composite micro system in the vicinity of the contact area, and at the same time the effect o the macro system is also incorporated. The FE contact results show the location and the distribution of the subsurface stresses and strains. For N fibre orientation there is a high shear stress region below the surface, from where the fibre/matrix interfacial failure initiates before propagation to the surface. These results are in good agreement with experimental results published in the open literature. In case of P fibre orientation the matrix is subjected to local plastic deformation while the characteristic deformation of the fibre is bending.

AB - The presented FE contact technique is applied to the problem of a steel ball indented into a composite material consisting of unidirectional continuous carbon fibres in a polyetheretherketone matrix. Indentation was carried out with fibre orientations either normal (N) or parallel (P) to the contact surface at fiber volume fraction 44%. The FE contact stress analysis of a fibre-matrix micro structure has some strong limitations. If FE micro models are used, only a very small (for example 0.1 × 0.1 mm) 3D segment can be modelled while the number of degrees of freedom (DOF) is immediately in the range of 100 000. If the anisotropic numerical models are used, there are no size limitations but the results can not describe the stress and strain states of a real fibre/matrix micro structure. The FE contact analysis involves both an anisotropic (homogeneous) macro and (inhomogeneous) micro contact analysis, following an approximate displacement coupling technique. This technique considers only the displacements along the coupled surfaces. The coupled solution provides a more realistic elastic deformation, stress and strain results of the composite micro system in the vicinity of the contact area, and at the same time the effect o the macro system is also incorporated. The FE contact results show the location and the distribution of the subsurface stresses and strains. For N fibre orientation there is a high shear stress region below the surface, from where the fibre/matrix interfacial failure initiates before propagation to the surface. These results are in good agreement with experimental results published in the open literature. In case of P fibre orientation the matrix is subjected to local plastic deformation while the characteristic deformation of the fibre is bending.

UR - http://www.scopus.com/inward/record.url?scp=0031961257&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031961257&partnerID=8YFLogxK

M3 - Chapter

AN - SCOPUS:0031961257

SP - 26

EP - 36

BT - Proc. ASME International Mechanical Engineering Congress and Exposition, Dallas, November 1997

PB - ASME

ER -