Tensile strength analysis of gripped carbon/epoxy rods

G. Portnov, Charles E. Bakis

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The tensile strength of carbon/epoxy composite rods used in tension-leg platforms, prestressed concrete, and post-tensioned concrete, for example, is highly sensitive to the method of load introduction to the ends of the rods by grips or anchors. The present paper analyzes the stresses imparted by the grips to a round-sectioned carbon/epoxy rod by various distributions of shear traction applied to the sides of the rod. The stresses were obtained using the linear theory of elasticity of anisotropic body and a series solution. It was found that severe concentrations of longitudinal and hoop stresses can exist in the rod near the loaded edges of the grips. Due to the singular nature of stresses at the grip edge, it is suggested to use an average stress criterion to estimate the tensile strength of the gripped rod. By applying the average stress criterion to a gripped intermediate modulus carbon/epoxy rod, a clear inverse relationship is shown between the tensile strength and the diameter of the rod. This relationship is independent of any size-dependent variation in inherent material strength. By changing the distribution of the applied shear tractions, the high stress concentrations can be mitigated, resulting in higher strength composite rods.

Original languageEnglish (US)
Title of host publicationSAMPE '07: M and P - From Coast to Coast and Around the World; Conference Proceedings
Volume52
StatePublished - 2007
EventSAMPE '07: M and P - From Coast to Coast and Around the World - Baltimore, MD, United States
Duration: Jun 3 2007Jun 7 2007

Other

OtherSAMPE '07: M and P - From Coast to Coast and Around the World
CountryUnited States
CityBaltimore, MD
Period6/3/076/7/07

Fingerprint

Tensile strength
Carbon
Tension-leg platforms
Prestressed concrete
Composite materials
Anchors
Stress concentration
Elasticity
Concretes

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)
  • Chemical Engineering (miscellaneous)
  • Building and Construction
  • Polymers and Plastics

Cite this

Portnov, G., & Bakis, C. E. (2007). Tensile strength analysis of gripped carbon/epoxy rods. In SAMPE '07: M and P - From Coast to Coast and Around the World; Conference Proceedings (Vol. 52)
Portnov, G. ; Bakis, Charles E. / Tensile strength analysis of gripped carbon/epoxy rods. SAMPE '07: M and P - From Coast to Coast and Around the World; Conference Proceedings. Vol. 52 2007.
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Portnov, G & Bakis, CE 2007, Tensile strength analysis of gripped carbon/epoxy rods. in SAMPE '07: M and P - From Coast to Coast and Around the World; Conference Proceedings. vol. 52, SAMPE '07: M and P - From Coast to Coast and Around the World, Baltimore, MD, United States, 6/3/07.

Tensile strength analysis of gripped carbon/epoxy rods. / Portnov, G.; Bakis, Charles E.

SAMPE '07: M and P - From Coast to Coast and Around the World; Conference Proceedings. Vol. 52 2007.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

TY - GEN

T1 - Tensile strength analysis of gripped carbon/epoxy rods

AU - Portnov, G.

AU - Bakis, Charles E.

PY - 2007

Y1 - 2007

N2 - The tensile strength of carbon/epoxy composite rods used in tension-leg platforms, prestressed concrete, and post-tensioned concrete, for example, is highly sensitive to the method of load introduction to the ends of the rods by grips or anchors. The present paper analyzes the stresses imparted by the grips to a round-sectioned carbon/epoxy rod by various distributions of shear traction applied to the sides of the rod. The stresses were obtained using the linear theory of elasticity of anisotropic body and a series solution. It was found that severe concentrations of longitudinal and hoop stresses can exist in the rod near the loaded edges of the grips. Due to the singular nature of stresses at the grip edge, it is suggested to use an average stress criterion to estimate the tensile strength of the gripped rod. By applying the average stress criterion to a gripped intermediate modulus carbon/epoxy rod, a clear inverse relationship is shown between the tensile strength and the diameter of the rod. This relationship is independent of any size-dependent variation in inherent material strength. By changing the distribution of the applied shear tractions, the high stress concentrations can be mitigated, resulting in higher strength composite rods.

AB - The tensile strength of carbon/epoxy composite rods used in tension-leg platforms, prestressed concrete, and post-tensioned concrete, for example, is highly sensitive to the method of load introduction to the ends of the rods by grips or anchors. The present paper analyzes the stresses imparted by the grips to a round-sectioned carbon/epoxy rod by various distributions of shear traction applied to the sides of the rod. The stresses were obtained using the linear theory of elasticity of anisotropic body and a series solution. It was found that severe concentrations of longitudinal and hoop stresses can exist in the rod near the loaded edges of the grips. Due to the singular nature of stresses at the grip edge, it is suggested to use an average stress criterion to estimate the tensile strength of the gripped rod. By applying the average stress criterion to a gripped intermediate modulus carbon/epoxy rod, a clear inverse relationship is shown between the tensile strength and the diameter of the rod. This relationship is independent of any size-dependent variation in inherent material strength. By changing the distribution of the applied shear tractions, the high stress concentrations can be mitigated, resulting in higher strength composite rods.

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SN - 9781934551004

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Portnov G, Bakis CE. Tensile strength analysis of gripped carbon/epoxy rods. In SAMPE '07: M and P - From Coast to Coast and Around the World; Conference Proceedings. Vol. 52. 2007