Research On The Distribution Of Tension In Notched Construction Parts
Report Number: WADD TR 60-906
Author(s): Neuber, Ing H.
Corporate Author(s): Technische Hochschule
Laboratory: Materials Central
Date of Publication: 1961-01
Pages: 76
Contract: AF 61(514)-1111
DoD Project: 7360
DoD Task: 73605
Identifier: AD0262132
Abstract:
The influence of various factors (notch-radius, depth of notch, notch-angle, material) on the stress concentration of notched flat bars was investigated theoretically and experimentally. The aim of the research work was the extension and completion of the methods available for the calculation of stresses in notched structural elements. For the by experimental determination of the strains and stresses mainly electrical strain gages were used; in addition to that measurements were made by means of the photoelastic stress-coat method. In considered cases the elastic stress-concentration factors, and the stress distribution over the minimum cross section were evaluated theoretically and experimentally for the elastic range. For the plastic range a method was developed taking into consideration the real stress-strain curve of the material. This method allows the calculation of the stress concentration factor (which is known to decrease with increasing load) in dependence of the nominal stress in tension and bending. We have evaluated in this way the diagrams for 4 different materials (steel St. 00.12, St 00.21, pure Aluminum, and Aluminum alloy, "Velodur"), which show the SCF vs. the nominal stress. Numerous tests with notched specimens of these materials confirm the theory. In these tests in the plastic range the strain distribution over the minimum cross section was also determined. Further theoretical investigations concern the treatment of V-shaped notches and the influence of the notch-angle in pure shear.
Provenance: IIT
Author(s): Neuber, Ing H.
Corporate Author(s): Technische Hochschule
Laboratory: Materials Central
Date of Publication: 1961-01
Pages: 76
Contract: AF 61(514)-1111
DoD Project: 7360
DoD Task: 73605
Identifier: AD0262132
Abstract:
The influence of various factors (notch-radius, depth of notch, notch-angle, material) on the stress concentration of notched flat bars was investigated theoretically and experimentally. The aim of the research work was the extension and completion of the methods available for the calculation of stresses in notched structural elements. For the by experimental determination of the strains and stresses mainly electrical strain gages were used; in addition to that measurements were made by means of the photoelastic stress-coat method. In considered cases the elastic stress-concentration factors, and the stress distribution over the minimum cross section were evaluated theoretically and experimentally for the elastic range. For the plastic range a method was developed taking into consideration the real stress-strain curve of the material. This method allows the calculation of the stress concentration factor (which is known to decrease with increasing load) in dependence of the nominal stress in tension and bending. We have evaluated in this way the diagrams for 4 different materials (steel St. 00.12, St 00.21, pure Aluminum, and Aluminum alloy, "Velodur"), which show the SCF vs. the nominal stress. Numerous tests with notched specimens of these materials confirm the theory. In these tests in the plastic range the strain distribution over the minimum cross section was also determined. Further theoretical investigations concern the treatment of V-shaped notches and the influence of the notch-angle in pure shear.
Provenance: IIT